JPH10244355A - Spray-pouring method and pouring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce enclosed blow holes in a vapor-deposited material and crack and gap in the inner part near a collector surface at the time of sprayed vapor-depositing by controlling the front ridge position of the vapor-deposited metal on the collector to a specific angle and depositing the sprayed metal on the collector. SOLUTION: A vacuum-melting chamber A and a spraying chamber B are arranged in a wall surrounding chamber C and the metal is melted in a refractory crucible 10 in the melting chamber A and poured into a molten metal pool part 14. The molten metal is discharged into an atomizer device 18 and the spraying S of atomized metal is executed onto the collector 30 arranged in the spraying chamber B. The front edge part of the vapor-deposited metal or alloy on the collector 30 is controlled so as to form the acute angle from about 10 deg. to about 300 deg. of the sprayed axis of this metal or alloy to the orthogonal axis, and the sprayed metal or alloy S is deposited on the collector 30 and the vapor-deposited layer is collected to form a poured product. By this method, the sprayed material vapor-deposited on the collector can further effectively be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for spraying molten metal or alloy onto a collector to obtain a spray deposit exhibiting a modified microstructure of low porosity.

[0002]

2. Description of the Related Art A spray casting method is described below.
Described in U.S. Patent No. 38,260,301;
According to this, a molten metal or alloy is sprayed and sprayed onto a collector surface provided in a spray chamber to form a cast product. The spray chamber generally holds the enclosed argon gas or otherwise non-reactive gas at atmospheric pressure, while spraying a molten spray onto the collector.

According to US Pat. No. 3,826,921, now-reissued application No. 31,767, which describes the temperature control of spray deposits regardless of mold temperature, in which case the spray deposit is controlled by spraying. The structure of the spray deposit is adjusted. For this reason, the emphasis of this patent is limited to the gas spraying conditions for the molten metal or alloy in the spray chamber, and the conditions in the spray chamber are not considered.

[0004]

However, in the method of spray casting a metal casting, argon or other gas that increases the porosity of the spray deposit is entrained,
Defects such as the tubular spray casting form providing porosity due to tears near its inner diameter and the unfortunately low yield of the sprayed castings from a commercial production standpoint. . In addition, the banding of the particles is
It is clearly seen in the spray casting of nickel based superalloys such as N718.

[0005]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention sprays a spray metal or alloy toward a collector provided in a spray chamber.
The leading edge of the metal or alloy deposited on the collector is moved about one axis perpendicular to the spray axis of the metal or alloy.
Control to make an acute angle from 0 ° to 30 °,
The invention is characterized in that a spray is collected on a collector, and a vapor deposition layer is collected to form a casting.

[0006] Also, an inner tubular member, an outer collector member partitioned by a space, a heat insulating material mounted in the space, and a device adapted for axial thermal expansion of the outer collector member, for spraying a sprayed metal or alloy. It is characterized by having a collector.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is to provide a spray casting method and a casting apparatus which solves the above-mentioned disadvantages by using a specific spray forming apparatus. Spray elements involved in, but not limited to, collector face orientation, collector heating, tub filters, and spray chamber pressure control techniques, including, but not limited to, spray sprays and sprays flying in a spray chamber. The spray material deposited on the collector provided in the chamber can be more effectively controlled.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;

Referring to FIG. 1, there is shown a schematic diagram of a spray casting apparatus using pressure control technology according to one embodiment of the present invention. This apparatus includes a vacuum melting chamber A and a spray chamber B provided in an enclosure C. A refractory crucible 10 is set in the melting chamber A, and in this crucible, a metal or alloy filling is induction-heated by an induction coil attached around the crucible. The crucible 10 can be tilted around the crucible trunnion T as shown, and a metal or alloy melt is poured into the refractory pool 14 at an appropriate superheating temperature. As shown in FIGS. 1 and 2, a melt holding chamber 14 b and a refractory melt discharge nozzle 14 c are attached to the basin 14. With this nozzle configuration, a melt discharge orifice 14 d (a typical example of the IN718 melt) is shown. The diameter dimension is 0.250 to 0.300 inch (for example, 0.292 inch). The melt is discharged through an orifice 14d to a lower atomizer device 18 attached below an intermediate wall 19 that separates a melt chamber A and a spray chamber B. The basin filters the metal and regulates its flow rate.

The melting chamber A is connected to an ordinary vacuum pump 20 through a pipe C1, and can be evacuated to an extremely high vacuum level of about 10 microns or less by using this pump prior to induction heating of the filling material in the crucible 10. Oxygen, nitrogen and other gases that contaminate and / or react with the melt by this arrangement are removed from chamber A during and prior to melting.

As an illustrative example of the present invention without limitation, an example in which a rod material of a known nickel-based IN718 superalloy is filled in a crucible 10 in an appropriate amount will be started. The crucible 10 is provided with an alumina-coated crucible that does not substantially react with the molten IN718 superalloy. The solid filling of the superalloy of IN718 is induction-melted in the crucible 10 by energizing the induction coil 12. This IN718 melt is suitably heated above the melting point of the alloy (200-300 ° F plus, for example, 300 ° F plus for IN718 superalloy melt) prior to casting. The melting temperature is measured using an infrared (IR) pyrometer. Once the melt is stabilized at the superheated temperature, the melting chamber A
Each of the spray chambers B uses a partial pressure of an inert or non-reactive gas, and a cylinder or a pressure vessel or the like from the atomizer 18 or filled with an inert gas (eg, argon) or a non-reactive gas at a high pressure. Gas source S1 and / or
Or backfill to a pressure level of 400 Torr or less via the exhaust gas from S2 and valves V1, V2.
For this, the S1 and S2 sources are combined with a single gas source,
A gas may be supplied to B. At this point, the superheated molten material is cast into the superheated hot water pool 14.

An upright type network-shaped ceramic (zirconia) filter 17 is attached to the basin 14. This filter has, for example, one per inch.
0 to 20 pores are provided, and the filter separates the molten metal holding chamber 14b for the basin and the casting chamber 14g. The casting chamber receives the molten material from the crucible 10 and the static chamber 14h.
Is placed on a melt discharge nozzle 14c, and a statically-dissolved melt is supplied thereto. The filter 17 is used for filtering the melt of the alloy when the melt flows from the casting chamber 14g into the static chamber 14h. At this time, in the chamber 14h, the melt flows into the melt discharge nozzle 14c, and this filter is used for the purpose of dispersing the turbulent flow from the casting chamber to the static chamber. The thermocouple row 15 in the basin records the metal temperature in the basin at the time of spray discharge.

The filter 17 is fixed to the side wall of the basin, and its structure is such that the width of the filter fits into an auxiliary slot cast in the basin, and the filter 17 is further vertical by a zirconia brick 17b. Is held. The filter 17 has an upper overflow channel 17a and a V-shaped bottom, which has a hollow top, extends in a direction perpendicular to the drawing, and has a pool of molten metal in the basin. It assists in the extrusion operation and also helps to concentrate emissions in this local filter area.

The melt injected from the crucible 10 into the preheated basin 14 is supplied to a nozzle heater 14j arranged on the periphery.
Is taken out from the melt discharge nozzle 14c provided with The flow rate of the melt from the discharge orifice 14d is adjusted to properly maintain the top level of the metal in the basin. IN7
Typical flow rates for the 18 superalloy melts are 75-95 pounds /
Can be considered a minute. The melt discharged from the hot-water discharge orifice 14d is poured into the atomizer device 18.

An atomizer device 18 for spraying a melt (shown in FIGS. 2 and 2A) has the shape described in US Pat. Nos. 4,779,802 and 4,905,899, the teachings of which are described herein with respect to the structure of the atomizer. Put. For example, in the atomizer device 18, a stationary primary gas nozzle 18a is attached to the periphery of the melt discharge nozzle 14c. This primary gas nozzle 18a is connected to a manifold 19a
A primary gas such as an inert gas (eg, argon) is used under a pressure of about 30 to 60 psig to prevent rebound of the melt discharged from the orifice 14d. To prevent rebound, the primary gas (argon) pressure should be I
In particular, 35 psig may be employed for the N718 melt. Manifold 1 for nozzle 18a for static pressure gas
9a receives gas from a gas source 22 provided outside the spray chamber B. The gas source may be a conventional high-pressure cylinder or bottle of an inert gas such as high-purity argon or another gas which does not substantially react with the melt.

The atomizer 18 is further provided with a scanning gas atomizer 18d, which receives the spray melt from the primary nozzle 18a, and supplies 70-140p supplied from the manifold 21 for spraying the melt.
A spray gas with an inert gas (eg, argon) is used under a spray gas pressure of about sig. In this case, the secondary atomizing gas pressure is preferably set to 1 for IN718 superalloy melt.
10 psig may be employed. Atomizer 18
d is because it oscillates under repeated cycles,
In each oscillation cycle, when the collector 30 moves and rotates in the axial direction with respect to its vertical axis under the control of the flow rate to the atomizer 18d, vibration is sequentially generated in accordance with an increase in the spray angle. It is assumed that it will occur.

In a non-limiting embodiment, which is limited to the references only, the atomizer 18d may be scanned repeatedly, in which case each cycle starts at the vertical axis of the atomizer and starts at the collector, as shown in FIG. 9A. The vibration operation is set around angles of about 1 °, 7 °, and 13 ° with respect to the rotation of. In other words, the atomizer 18d oscillates around an angle of 1.06 ° with respect to the vertical axis during one revolution of the collector 30, then 7.41 ° with respect to the vertical axis for one revolution of the collector, and then the collector. A rotation of about 13.58 ° relative to the vertical axis for one revolution of. This oscillating cycle operation is repeated with the axial movement of the collector 30 from the deposition start position to the final deposition position under a single pass, so that the desired deposit is formed on the collector as a preform. Under the scan cycle of the atomizer 18d to accommodate the increase in the oscillation angle in response to each rotation of the collector, the spray deposits overlap as shown schematically in FIG. Become restricted. That is, the collector 30 is an atomizer 18d.
On the other hand, in FIGS. 1 and 6 during the single pass, the shaft moves from the right direction to the left direction, and a preform is obtained on the collector surface 104a. In FIG. 9B, the so-called "sweet spots" of the so-called spray deposits are usually spaced apart from one another on the collector surface at equal intervals R, and are usually with respect to the horizontal axis (or if a non-horizontal nozzle / collector orientation is employed). ,
(With respect to the axis perpendicular to the spray axis of the spray nozzle 18d) 10
Within an angle range of ２０20 °, for example, under an angle of 15 °,
A generally uniform spray deposit with a directional leading edge is obtained.

The rotational speed of the collector 30 depends on the variation of the outer diameter of the collector surface 104a, and the centrifugal stress on the spray cast deposit is minimized. For example, this stress will not exceed 20 psi. Atomizer 1
The vibration of 8d occurs according to the rotation speed of the collector 30,
Vibrations of about 1 °, 7 °, 13 ° should always be observed for one revolution of the collector, irrespective of the number of revolutions of the collector, and should be repeated until the desired deposit is obtained. In this case, the residence time (spray duration) for each oscillation of the cycle also decreases as the rotational speed (rpm) of the collector increases.

The manifold 21 of the scanning atomizer 18d receives a spray gas from a gas source 23 provided outside the spray chamber B. Examples of the gas source include a high-pressure cylinder and a bottle filled with an inert gas such as high-purity argon or another gas which does not substantially react with the melt.

The stationary gas nozzle 18a is provided with a plurality (12 sets) of gas discharge orifices 18f (0.055 inch in diameter) spaced along the circumference of the melt discharge orifice 14d shown in FIG. 2A. The scanning gas atomizer 18d has a plurality (24 sets) of gas discharge orifices 18i (0.1570 inches in diameter) spaced along the circumference of the atomizer spray opening 18j, also shown in FIG.
Provide. The opening 18j of the atomizer 18 and the gas discharge orifice 18i are attached so that the metal or alloy melt can be sprayed to some extent effectively when spraying fine molten droplets. Atomizers employed in this case are disclosed in U.S. Pat. Nos. 4,779,802 and 4,905,899, the teachings of which are incorporated herein by reference. Here, the spray S of the sprayed metal or alloy is applied to the spray chamber B during the passage of the spray S shown in FIG.
Is sprayed toward the lower mild steel support 104 of the collector 30 provided therein.

The collector 30 is mounted on the double coaxial mechanism shown in FIG. 3, and the collector is rotated by using this mechanism, and the collector is moved from the axial start position to the final end position with respect to the atomizer 18d. The inner shaft 31 rotates the collector via a bearing stand between the shafts 31 and 33, while the outer shaft 33 is connected to the collector 30.
And the collector causes the atomizer 18d to perform an axial movement. The vacuum seal assembly 31b and the bearing device are mounted in the double wall chamber. The rotating shaft 31 is driven to rotate using an AC servomotor 34. Although not shown, the AC servomotor 34 and the AC servomotor 32 are respectively mounted on a common slide or a carriage. This common slide or carriage is driven via a conventional ball / screw drive (not shown), on which the motors 32, 34 are mounted and the shaft 31 is rotated, while the sliding movement and the axial movement of the shaft 33 are carried out. And are integrated.

The collector 30 is provided with an outer collector support surface 104a so that the spray cast metal or alloy to be deposited on the collector has the desired shape.
The standard separation distance between the outer surface 104a and the atomizer 18d is about 23 to 29 inches.
In the case of spraying a superalloy melt of No. 8 this distance is for example 2
6 inches.

Outer collector surface 104 of collector 30
The shape of a is cylindrical, and it is also possible to obtain a ring or tube-shaped deposit D having the inner and outer cylindrical collector surfaces 104a required for the ring or tube. Alternatively, the shape of the collector surface 104a is
The tapered cone or other shape shown in FIG. 6 can be used to form the desired spray cast deposit preform thereon.

In one embodiment of the present invention, the collector 30 is not shown in FIG. 1, but usually employs a stationary induction coil and performs a preheating operation prior to spraying the melt. The power and time for collector preheating also depend on the size and shape of the support, in which case the final preheat temperature of the support is IN7
Approximately 1700-1800 ° F for 18 nickel alloy
It is. In contrast, a DC plasma torch can replace this induction preheating operation, as will be shown later. In spray casting of IN718 superalloy, another material may be used for the collector depending on the metal or alloy to be spray-cast, but this collector can be made of mild steel.

The outer surface 104a of the cylindrical collector employed
The standard dimensions are about 3.5 to 60 inches in outside diameter and about 60 inches in length. In this case, the spray length (spray length) that can be employed is about 56 inches.

FIG. 3 shows a more detailed portion of the collector 30. In this case, the collector 30 has a hollow cylindrical structure, is simple and inexpensive, can be easily changed in the manufacturing operation, and has a heat insulating inner diameter. The structure is compatible with the thermal expansion of the collector. The collector 30 supports the weight of the shaft holding end plates 100a, 100b and other collector portions, and the SS reinforcing beam 102 for concentrically positioning the end plates 100a, 100b, and the mild steel collector support 104, Collector surface 10 with respect to the collector axis
4a. The shaft end 102a of the reinforcing beam 102 is welded to the hub 112. Tension ring 106 and corresponding ring bolts and nuts 108, 1 1
Reference numeral 09 is connected to the right-hand end plate 100b in FIG. 3, and tightens the collector support 104 made of mild steel into a 360-degree square ring groove found between the axial end plates 100a and 100b. Tighten the reinforcement beam with tension ring 106 using tension ring clamping pin 106a, which pin passes through the proper diameter hole (not shown) in tension ring and reinforcement beam 102 and retains the clamping pin at its end. The ring 106 is fastened to the reinforcing beam by using a retaining ring for the ring. The left-hand support end plate 100 a is fixed to the hub 112 using screws 114. Next, 112 is sequentially rotated and tightened to the terminal hub 31a of the rotating shaft by using a spline and bolt connecting tool shown in the figure. The shaft 33 is sealed with a vacuum 0-ring pack 31b.

The diameter of the end plates 100a and 100b can be changed to form the outer shape of the tapered collector of FIG. 6, in which case the outer diameter of the support 104 is reduced from one end to the other end, or the outer diameter is reduced. The configuration is reversed.

Nut 109 of tension ring bolt 108
(Compressible) graphite felt washer 1 between the faces of the end plates 100b facing outwardly and facing outward.
Attach 10 and allow the collector support to stretch while receiving the heated metal spray deposit with this washer while preheating the collector. The dimensional stability of the collector is also maintained by this compatible mechanism against thermal expansion.

The annular space 120 provided between the outer diameter of the reinforcing beam 102 and the inner diameter of the collector support 104 has a K.
Fill aowool insulation (partially shown) to maintain the temperature of the support 104 during the spraying operation at a temperature sufficient to sufficiently reduce the porosity due to rips in the inner diameter. For example, as a comparative example, it is sufficient to compare the upper preform of FIG. 8A without using the heat insulating material with the lower preform of FIG. 8B using the heat insulating agent.

While depositing the spray S on the upper surface, the collector 30 is rotated with respect to the atomizer 18 by using a drive motor and a shaft 31 connecting the motor and the collector 30. By this operation, the spray S can be deposited on the entire periphery or circumference of the collector outer surface 104a. The rotational speed of the collector is usually IN718
100 to 2 for a melt flow rate of 75 to 95 lb / min.
It is set to about 00 rpm. The rotation speed of this collector is
It is specified by the allowable centrifugal stress applied to the deposit. For example, it is as if the centrifugal stress did not exceed about 20 psi. As described above, the atomizer 18d provides about 1 °, 7 °, and about 1 °, 7 °, for each rotation of the collector 30, as the collector rotates and operates in the axial direction until deposits are formed along the desired length of the collector. Operated under a repetitive cycle including a 13 ° oscillation.

Preferably, the collector has its end plate 100
A peripheral "start" surface 104b is provided near a to indicate a standard angle, and a surface spray of spray metal or alloy is started on this surface. The spray material is trapped in the surface area 104b at this angle, and the material in the area 104a accumulates "quickly" (see FIGS. 4A, 4B, 4C4D and "Start" in FIGS. 7, 8). Preservation of the material in the part is achieved. That is, if there is no 104b in the collector area, there should be spillage or loss of the deposition material,
This is unfavorable for the components and also leads to a loss of deposition material on the collector. Attaching the surface area 104b also increases the shielding effect between the molten metal spray and the collector end plate 100a. Similarly, an angle maintaining surface area (not shown) may be attached near the end plate 100b on the opposite side or a separate place of the collector 30. For example, in order to take advantage of the edge region characteristics of the deposited material shown in FIGS.

In practicing the present invention, the spray chamber B
Is connected to the conduit C2 provided on the opposite side during the period from the atomizer 18d to the vacuum device, and the spray device B is evacuated to a sufficiently high degree of vacuum by the vacuum device. Collector 3
When spraying the spray S toward zero, the gas partial pressure in the spray chamber B (for example, when the gas released from the stationary atomizer 18a and the operation atomizer 18d is argon) is selected to be sufficiently low. I can do it. That is,
The vacuum apparatus should exhaust the argon gas from the spray chamber B sufficiently quickly. When the spray S is sprayed onto the collector 30 for vapor deposition, it is necessary to keep the selected gas partial pressure in the spray chamber sufficiently low. Preferably, the gas partial pressure in spray chamber B is kept as low as about 400 Torr to about 10 Torr. Gas partial pressure in chamber B is about 250 to 400 torr
Torr or less, but this requires IN718
In the case of spray casting of the superalloy melt, the following vacuum apparatus is used.

As a preferred vacuum device for obtaining the above-mentioned partial pressure of gas in the spray chamber B, single-stage and two-stage blowers (pumps) B1, B2 are mounted in series with an intercooler B3 mounted between the blowers. . The first stage blower B1 is a commercially available Stokes HPB622 blower, while the second stage blower B2 is a commercially available Hibbon SIAV25 blower. When this is connected, the first and second stage blowers B1, B2 maintain a sufficient degree of vacuum and apply a spray gas flow at 110 psi (that is, equivalent to about 900 ft3 / min) in the spray chamber B. The spray chamber B is capable of holding a vacuum of 200 or 400 Torr or less during spray deposition operations under standard operating conditions. The degree of vacuum in the spray chamber B is controlled by a proportionally integrated induction controller CC (for example, Hone).
YDC UDC3000 controller), but the blowers B1, B
The regulating valve VV between 2 and the spray chamber B is automatically controlled.

Before the spray spray S is blown into the spray chamber using the collector 30, the spray chamber B is initially evacuated using the vacuum pump 20 according to the exhaust conditions of the melting chamber A.
It is evacuated to less than about 1 micron to remove oxygen, nitrogen and other undesirable gases. After melting the alloy in crucible 10 under high vacuum, both chambers A and B are backfilled with a partial pressure of about 400 Torr or less of an inert gas (eg, high purity argon) or a non-reactive gas. The backfill gas is provided by the atomizer 18 or the gas sources S1 and / or S2.
It is also supplied via a valve V1 and / or V2 from a high-pressure cylinder or bottle for high-purity inert or non-reactive gas. A single conventional gas source (not shown) can be supplied to chambers A and B via conventional valves (not shown) for this same purpose. After spray chamber B is filled under a partial pressure of an inert or non-reactive gas of about 400 Torr or less,
The melt is filled and supplied to an atomizer 18 via a basin 14 and a spray spray S is blown towards a preheating collector 30 on which a typical layer thickness of 0.5-4.
A 0 inch spray cast deposit is obtained. The collector 30 is rotated in the axial direction with respect to the atomizer 18d in the single pass to deposit a spray material to obtain a desired preform on the collector surface 104a.

When a nickel-base superalloy such as IN718 is spray-casted in particular, the flow rate ratio of spray gas / metal, which is a condition adopted in carrying out the present invention, is set to about 1.2: 1 as a standard value. It is not limited to this. An advantage of the present invention is that the quality of the spray deposit is not significantly affected by the gas / metal flow ratio even when the spray pressure in the spray chamber B is near atmospheric pressure.

When the collector 30 is rotated as described above and the cycle operation is repeated, the spray S is scanned and moved at the collector 30 using the scanning atomizer 18d. In this case, about 1 °, 7 °, and 13 °
This also includes the vibration operation. When the spray S is deposited toward the collector 30, the vacuum pumps B1 and B2 are operated, and if the gas partial pressure (for example, the argon partial pressure when argon is used as the spray gas) can be set to about 10 Torr to about 400 Torr, It can be said that it was kept at a low level.

Referring to one embodiment of the invention, FIG.
The collector 30 is preheated during the spraying operation using a DC plasma torch or gun, as shown at 6B, 6C. In particular, by using a low pressure type DC arc plasma preheating torch or gun, the collector surface 104 directly above the leading edge LE of the deposited material can be effectively heated. In other words, the heating of the support can be performed on site during the deposition. By using a torch or gun 130 to heat the portion immediately before the deposit, the following effects can be obtained. 1) The bond between the deposit and the support 104 is enhanced. 2) As the thermal condition of the interface with respect to the deposit, 1700 to 1700
Maintaining a temperature of 1800 ° F. reduces porosity due to cracks in the inner diameter. 3) When thermal energy is essential for the operation, the thermal energy can be concentrated at the leading edge of the deposit.

When the collector support 104 is preheated in the field by using the collector having a structure having the torch 130 and the heat insulating material 122, the porosity due to the crack generated in the inner diameter portion of the deposit is reduced concomitantly. Therefore, the heat condition in the inner diameter portion is also improved. The DC plasma arc torch or gun device 130 is fitted with a standard conventional argon + helium plasma gun used for vacuum plasma spraying. The torch or gun is water cooled via a suitable water line 150, where the water line is
30 and a suitable gas for plasma is supplied via a suitable gas line (not shown) connected to the gun.

Alternatively, the collector can be heated with the aid of the induction preheating technique described above. However, this induction preheating method should be used only when preheating the collector prior to the spray operation, while the technique of using a DC plasma source can be used before and during the spray operation.

The torch or gun 130 is shown in FIGS. 6A, 6B,
Attach to a slide mechanism in spray chamber B as seen at 6C. The slide mechanism is used to hold the boom 142, which is a part of the torch assembly device. Boom 14
2 rests on a slider 144, which can be moved by a servomotor 145 and a ball / screw mechanism 146 in a direction parallel to the diameter of the collector 30, the plume of the torch being sprayed concentrated on the support surface 104 during the spraying operation. The radial size of the deposit can be adjusted. See FIG. 6C for this.

The torch 130 and the collector 30 are initially set at the start position on the collector 30 by the axial movement of the double-shaft mechanism. By adjusting the torch 130,
The plume form of the plasma is the collector support surface 104
It can be manipulated to make any angle that is orthogonal to a or using a preset tapered collector surface. During spraying, as the collector 30 moves axially (from right to left in FIG. 6B), the plasma plume is also directed just forward of the deposit leading edge LE for the above purpose.

The point of the present invention in the spray casting operation is to form an acute angle with the axis perpendicular to the spray axis of the spray nozzle 18d for the purpose of reducing the porosity of the breach in the inner diameter portion, regardless of the pressure in the spray chamber. , 9A in determining the outer surface angle of the leading edge LE of the spray deposit. For this purpose, the vibration angle of the spray nozzle 18d may be appropriately adjusted. Alternatively or additionally, the outer surface 104a of the collector (or alternatively the axis angle of the collector 30)
To deviate from the horizontal direction. For example, the angle AA (see FIG. 1) of the collector surface 104a is set to 10 to 30 °, for example, 25 ° (or separately to make an acute angle to the horizontal axis) with respect to the horizontal direction, so as to reduce the porosity due to the internal rift, The quality of the spray deposited layer can be improved. When the angle AA of the collector surface 104a indicates 45 ° or 0 ° with respect to the horizontal direction, a spray-cast IN718 deposit can be obtained on the collector 30, and in this case, the porosity of the inner diameter portion is optimal. It can be less than or equal to the value. For example, regarding the porosity of the inner diameter crack in the deposit, FIGS.
B, 4C, 4D (AA angle is 0 °) and FIG. 7 (B) (AA angle of tapered collector surface 104a 45 °), and FIGS. 7 (A), 8 (A), 8 (B) corresponding thereto (The AA angle of the tapered collector surface 104a is 25 °). The preforms shown in FIGS. 4A, 4B and 4C were sprayed at an angle of 0 ° (angle A in FIG. 1).
A; that is, see the figure configuration where the collector axis is horizontal)
Things. It can be seen that the spray deposits in FIGS. 4C, 4D, 7 and 8 are divided into two parts after the spray operation.

For adjusting the AA angle of the collector surface 104a with respect to the horizontal direction, a tapered collector support 104 shown in FIG. 6 is used. Instead of this, the double-axis mechanism and the coaxial AC servomotors 31 and 33 are attached to adjust the angle AA, but the axis angle with respect to the horizontal axis may be changed for the same purpose.

After spray casting, 0.5 to 4.
A 0 inch thick deposition ring or tube is cooled in spray chamber B under a relative vacuum. The spray casting ring or tube may then be removed from the collector 30 at ambient temperature and the isostatic pressure may subsequently be applied by hot isostatic pressing to consolidate the deposition ring or tube.

By keeping the gas partial pressure in the spray chamber B low according to the present invention, the temperature of the droplets in the flying spray state in the spray chamber B and the temperature of the spray metal or alloy deposited on the collector 30 can be reduced. Effective control and a reduction in the mechanism ratio at the time of spraying can be achieved.
For example, a porosity of 0.9% by volume under a spray pressure of 400 torr.
4B can be compared with the state of FIG. 4D with a porosity of 2.1% by volume under a spray pressure of 730 torr. In fact, the use of spray chamber pressure control techniques can reduce the heat loss due to convection of droplets, which would otherwise occur at relatively high spray chamber pressures, or reduce the deposition metal or alloy on collector 30. It is possible to achieve early thermal equilibrium or to maintain a relatively high temperature of the spray droplets sprayed in the spray chamber B and deposited on the collector.

4A, 4B, 4C and 4D were obtained under low pressure (eg 400 Torr) in spray chamber B according to the invention.
FIG. 4C illustrates the difference between the IN718 ring of spray deposit (FIG. 4A) and the IN718 ring by spray deposition obtained at relatively high pressure (eg, 730 Torr) in spray chamber B (FIG. 4C). In particular, the porosity of the crack at the inner diameter portion (the inner diameter portion of the ring near the collector 30) and the porosity due to the embedding gas in the ring deposition are both significantly reduced, while the porosity due to the same uniform particle size (for example, 6% by ASTM). ~
6.5 equivalents) is retained in the microstructure of each ring, in particular without showing banding or layering due to the particles.

FIGS. 4B and 4D show the microstructure of the spray ring of FIGS. 4A and 4C, respectively. The argon buried in the spray deposit according to the present invention (eg, 2.1% by volume porosity) is compared to the buried argon in the spray deposit under a relatively high pressure of 730 Torr (eg, 2.1). Volume% porosity). As a further example, the embedding argon in the ring by Waspaloy spray casting according to the invention is 0.5 ppm by weight, whereas W obtained under pressure conditions near atmospheric pressure in spray chamber B.
Buried argon in the ring by aspaloy spray casting shows a 1.5 ppm weight concentration.

FIG. 5 also shows a spray chamber B according to the invention.
The porosity during welding with an electron beam in the Waspaloy ring by spray deposition obtained at medium and low pressures (eg 400 Torr) is low (FIG. 5A), while the relatively high pressure in spray chamber B (eg 730 Torr) The porosity at the time of welding with an electron beam in the Waspaloy ring of the spray deposition obtained in (1) is high (FIG. 5B). FIG. 5B shows that the sample sprayed at 730 Torr has a high porosity in the area exposed to the welding heat.

According to the pressure regulation technique in the spray chamber, the amount of buried spray gas in the metal or alloy deposited on the collector 30 is reduced (determined by the porosity) and the collector outer surface 3
The crack porosity near 0a is also reduced, and the thermal equilibrium conditions in the deposit during the spray deposition operation are also improved, thereby ensuring substantially uniform grain size through the deposited layer thickness found on the collector 30. Furthermore, the formation of relatively large diameter rings or tube deposits on the collector 30 is promised. For example, a deposit having a large diameter of, for example, 30 inches or more is obtained, and on the other hand, no overlapping layer formation of particles or the formation of a strip thereof is observed in the deposit.

In the spray casting operation of 400 Torr or less according to the present invention with respect to the conventional operating pressure of 730 Torr, since the temperature of the spray and the temperature of the deposit are increased accompanyingly,
Since the convective cooling is reduced, the method and apparatus for producing a relatively large-diameter preform (evaporated product) can be measured and evaluated. The increased spray / deposit temperature allows for spraying of large preforms at relatively slow rotational speeds (reduced centrifugal stress), while reducing porosity due to cracks in the bore. Even if the processing window has a large diameter that can be effectively widened, an acceptable thermal environment is maintained.

Under spray casting at 400 Torr or less according to the present invention, porosity due to cracks in the inner diameter is reduced, the amount of gas embedded in the deposit is reduced, and the uniform microstructure of the deposit is reduced. It is also possible to widen the processing window that can be obtained in various shapes and sizes to support the above. In addition, the technique of adjusting the support angle based on the implementation of the present invention also suppresses the generation of pores due to cracks in the inner diameter part, and assures the shape and size of various components that represent the microstructure of the homogeneous deposit. Window expansion is also conceivable. By utilizing the above-described cycle of the scan atomizer, utilizing the adiabatic collector, and utilizing the DC plasma arc torch according to another embodiment of the present invention,
The porosity of the rift in the inner diameter portion is also kept low, and the enlargement of the processing window that produces the shape and size of various constituent devices exhibiting a uniform microstructure of the deposited layer is also considered.

As a result, according to the present invention, it is possible to obtain a spray-deposited ring and a tube in which a crack or a porosity of an inner diameter portion is reduced, and on the other hand, the spray-deposited result at a relatively high pressure (for example, 730 torr) is obtained. And a uniform particle size distribution over the spray deposited layer thickness without any banding of the particles is guaranteed.

Although several embodiments of the present invention have been shown and described in detail, various changes and modifications can be made without departing from the spirit and scope of the present invention, as set forth in the appended claims. Will understand.

That is, using a specific spray composition device,
It is an object of the present invention to provide a spray casting method and a casting apparatus that solves the above-mentioned deficiencies, and has a configuration feature related to, for example, an improved spray collector, a collector surface orientation, a collector heating, a filter for a hot water pool, and a spray chamber pressure control technology. However, the present invention is not limited to such spray elements.However, according to the control technique, it is possible to more effectively control the spray material flying on the spray chamber and the spray material deposited on the collector provided in the spray chamber. I can do it.

According to the present invention, one embodiment is assumed. According to this, the vibration of the spray atomizer (spraying device) and / or the direction of the collector is controlled to reduce the porosity of the crack in the inner diameter portion. The result of enhancing the quality of spray deposits. A deposit leading edge with an outer surface with a selected sharp mounting is obtained. The present invention also envisages another embodiment, according to which the collector mounted close to the leading edge of the deposit is functionally heated for the same purpose. In this case, the collector is heat-insulating, and as shown in another embodiment, the collector is compatible with the thermal expansion of the collector. In addition, in the additional embodiment, the scanning speed and the scanning distance of the scanning atomizer are controlled depending on the rotation speed of the collector. The actual atomizer residence time (spray time) is also reduced with increasing collector rotation speed. Further, a hot-water pool with a built-in filter mechanism is attached, and the statically filtered melt is supplied to the atomizer for further advantages.

The particular embodiment of the present invention preferably employs pressure control techniques, which allow the spray chamber to be evacuated in-situ when spray depositing the sprayed metal or alloy on the collector. Thus, the inert or non-reactive gas partial pressure in the spray chamber is set to no more than 400 Torr, preferably in the range of about 10 to about 400 Torr or less. This lower gas pressure in the spray chamber keeps the spray spray temperature in the spray chamber and the spray material temperature deposited on the collector in the spray chamber relatively high. Note that the amount of gas embedded in the deposit is smaller than the amount of gas in the deposit sprayed at near atmospheric pressure. Sprays for spraying molten metals or alloys use a blowing gas, such as argon or other gas that is inert or non-reactive with the melt, to deliver the melt to a spraying device, which melts as about 400 molten droplets. Atomize into a spray chamber below Torr. The spray chamber has an initial (backfill) inert or non-reactive gas partial pressure.
Thereafter, the gas partial pressure in the spray chamber is exhausted on site, the introduced spray gas is removed from the spray spray, and the spray chamber is sprayed on the collector for about 400 hours during vapor deposition.
It is kept below torr. In the case of spray castings such as rotationally symmetric rings and tubes, the collectors can also be rotated in a single pass configuration with respect to the spray device.

According to the spray casting method and apparatus of the present invention, a relatively high-temperature spray spray and a deposit can be obtained, the number of embedded pores in the deposit can be reduced, and the inner diameter near the collector surface during spray deposition can be reduced. Crevice gaps are also reduced, and the thermal equilibrium state in the deposit during spray deposition is improved.

[0058]

As is apparent from the above detailed description, the sprayed metal or alloy is sprayed toward the collector provided in the spray chamber, and the leading edge portion of the metal or alloy deposited on the collector is replaced with the metal. Or, control by forming an acute angle of about 10 ° to 30 ° with respect to the axis perpendicular to the axis of spraying of the alloy, accumulate the spray on the collector, collect the deposited layer and form the cast product, It is an object of the present invention to provide a spray casting method and a casting apparatus for solving the above-mentioned defects by using a spray constituting apparatus, and the constitutional features thereof include, for example, an improved spray collector, a collector surface orientation, a collector heating, a filter for a hot water pool and Spray elements related to, but not limited to, spray chamber pressure control technology include, but are not It is possible to more effectively control the spray material flying on the spray chamber and the spray material deposited on the collector provided in the spray chamber.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an apparatus according to an embodiment of the present invention when implementing a low gas partial pressure control technique of the present invention.

FIG. 2 is a cross-sectional view of a spray device (atomizer) and a basin when the present invention is carried out.

FIG. 2A is an enlarged view of a main part of FIG. 2;

FIG. 3 is a cross-sectional view of one collector for a spray melt.

FIG. 4A is a characteristic photograph of an IN718 nickel-base superalloy material sprayed on a mandrel having a diameter of approximately 20 inches at a pressure of 400 Torr while being sprayed.

FIG. 4B is a photomicrograph showing grain size and porosity of an IN718 nickel-based superalloy material at 400 Torr pressure and as sprayed.

FIG. 4C is a photograph of the characteristics of an IN718 nickel-base superalloy material sprayed on a mandrel of approximately 20 inches diameter at 730 Torr pressure, as sprayed.

FIG. 4D is a photomicrograph showing grain size and porosity of IN718 nickel-based superalloy material as sprayed at 730 torr.

FIG. 5A is a photomicrograph showing a hot isostatically sprayed Waspaloy nickel-based superalloy material sprayed at 400 torr under electron beam welding heat.

FIG. 5B is a micrograph showing a hot isostatically sprayed Waspaloy nickel-based superalloy material sprayed at 730 torr, receiving electron beam welding heat.

FIG. 6A is a side view of a DC plasma heating torch useful for practicing the present invention.

FIG. 6B is a plan view of the preheating torch of FIG. 6A.

FIG. 6C is a front end view of the preheating torch of FIG. 6A.

FIG. 7 (A) shows an angle of 25 ° (see AA angle in FIG. 1) at the collector surface, and in this case the central part of the deposit forms an angle of 45 °, approximately 20 inches in diameter. 5 is a photomicrograph of an IN718 nickel-base superalloy material as sprayed at 730 torr on the tapered collector surface of FIG. FIG. 7B shows an angle of 45 ° to the collector surface, where the central portion of the deposit forms an angle of 25 ° and a 730 Torr pressure on the approximately 20 inch diameter tapered collector surface. IN as sprayed
It is a microscope picture of 718 nickel system superalloy material.

FIG. 8A shows a spray sprayed at 400 torr on a tapered collector surface approximately 20 inches in diameter with a central portion forming an angle of 25 ° (see AA angle in FIG. 1). It is a microscope picture of IN718 nickel system superalloy material. FIG. 8 (B) shows that the central portion forms an angle of 25 ° (FIG. 1).
AA angle of about 20 inches) on a tapered collector surface as sprayed under 400 Torr pressure
It is a microscope picture of 718 nickel system superalloy material.

FIG. 9A illustrates a collector outer surface having a spray cast deposit and an oscillating cycle showing the spray angle increment of the injection nozzle.

FIG. 9B is a diagram illustrating an overlap state of the spray distribution concentrated on the outer surface of the collector as a result of the vibration spray cycle.

[Explanation of symbols]

 10 crucible 14 hot water pool 17 filter 18 atomizer 30 collector

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor David A. Cook United States 49420 Heart, Michigan. 23 Apple Street (72) Inventor David P. Ingersoll United States 49437 Montague, Michigan Indian Bay Road 8651 (72) Inventor Jacques-W. Van Heath United States 49457 Michigan Twin Lake Holton Duck Lake Road 4848 (72) Inventor Robert Di. Adia United States 49448 Nunica, Michigan e. 8395 Pontarna Road

Claims (18)

[Claims] A metal or alloy spray is sprayed toward a collector provided in a spray chamber, and a front edge portion of the metal or alloy deposited on the collector is set to an axis orthogonal to a spray axis of the metal or alloy. About 10 ° to 30 °
A spray casting method, comprising forming a spray on a collector, collecting vapor deposited layers, and forming a cast product. 2. Controlling the oscillation cycle of the scanning atomizer to form the leading edge portion, giving the cycle several continuous oscillations, and increasing the oscillation angle with respect to the preceding oscillation to increase the leading edge portion. The spray casting method according to claim 1, wherein 3. The spraying method according to claim 2, wherein the scanning speed of the atomizer is made dependent on the rotation speed of the collector, and the residence time of the atomizer is reduced as the rotation speed of the collector increases. Casting method. 4. The method according to claim 1, wherein the collector is placed in a spray chamber, and the collector surface is disposed at an acute angle in a range of about 10 ° to about 30 ° with respect to a horizontal direction.
Spray casting method described in 1. 5. The spray casting method according to claim 4, wherein the method is attached to a shaft mechanism inclined at about 10 ° to about 30 ° with respect to a horizontal plane. 6. The method of claim 4, wherein the collector surface is a tapered cone. 7. When spraying to a collector, the partial pressure of gas in the spray chamber is maintained in a range of about 10 torr to about 400 torr or less, and the porosity of the deposit on the collector is reduced by reducing the amount of entrained gas. 2. The method according to claim 1, wherein the temperature of the spray in the spray chamber is increased so as to lower the temperature. 8. The spray temperature in the spray chamber when spraying to the collector, keeping the gas partial pressure between about 10 Torr and about 400 Torr and effectively reducing the crevices inside the deposit on the collector. The spray casting method according to claim 7, wherein 9. A rotating and axially moving collector provided in the spray chamber is scanned by an atomizer for generating a spray of a spray metal or alloy, and the collector is rotated and axially moved to prevent the preceding vibration. The atomizer is vibrated in a cycle consisting of several continuous vibrations to increase the vibration angle, and the collector is rotated and moved in the axial direction to repeat the cycle operation, and the spray is concentrated on the collector A spray casting method comprising collecting objects and forming a cast product. 10. A vapor-deposit having a leading edge portion of a vapor-deposited metal or alloy formed at an angle of about 10 to 30 ° with respect to an axis perpendicular to a spray axis of the metal or alloy by adjusting a vibration angle. The spray casting method according to claim 9, wherein the method is configured. 11. Regardless of the rotational speed of the collector,
The spray casting method according to claim 9, wherein each vibration is caused for one rotation of the collector. 12. Spraying a spray metal or alloy onto a collector installed in a spray chamber, heating the collector near a front edge of the deposit according to the formation of the deposit, concentrating the spray on the collector, A spray casting method having a configuration in which a deposit having a leading edge is formed. 13. The method of claim 12, wherein the collector is heated by concentrating a plume of a DC plasma arc torch on the collector near the leading edge of the deposit. 14. An apparatus for receiving spray of spray metal or alloy comprising an inner tubular member, an outer collector member separated by a space, insulation material mounted in the space, and a device adapted for axial thermal expansion of the outer collector member. A casting device characterized by having a collector. 15. An end plate provided near an axial end of said outer collector member, said end plate extending in a plurality of axes and connected to said inner tubular member by means of adjustable connectors. The casting apparatus according to claim 14, wherein the thermal expansion is absorbed by using a compressible washer mounted between the end plate and the end plate. 16. A basin for supplying a melt to an apparatus for spraying a melt, wherein the basin is provided with a built-in ceramic filter to form a pouring (casting) chamber in the basin. A casting apparatus for receiving a melt from a melt source, further providing a static chamber above a melt discharge nozzle connected to the melt spray device, and supplying the static chamber to the static chamber. 17. The casting apparatus according to claim 16, wherein the ceramic filter incorporates one of the upright ceramic filters with a regulated pore size, thereby filtering the melt. 18. The casting apparatus according to claim 16, wherein the ceramic filter is mounted on a side portion of the basin using a width of a filter to be inserted into a slot in the basin.