JPS6089307A - Manufacture of abrasion-resistant composite layer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a method for manufacturing a wear-resistant composite layer, and more particularly, to a method for manufacturing a wear-resistant composite layer, which is suitable for the inner diameter portion of a cylindrical part that requires wear resistance, such as a cylinder of a plastic molding machine. The present invention relates to a method for manufacturing a coating layer of a wear composite material.

[Prior art and its problems]

Conventionally, centrifugal casting is known as a method for manufacturing a wear-resistant coating layer on the inner diameter of a cylindrical part such as a cylinder of a plastic molding machine. In this centrifugal casting method, one opening of the cylinder is covered with a steel plate, ceramic powder and self-fusing alloy powder are added to the other opening, and then the steel plate is covered.
The self-fusing alloy is heated to 950-1250°C in a furnace to melt it, then taken out of the furnace and cooled to below the melting point of the self-fusing alloy while rotating the cylinder, and then slowly cooled in the furnace. It forms a covering layer. However, in this method, in order to form a composite coating layer with a uniform thickness on the inner surface of the cylinder, the mixture of the molten self-fusing alloy and the ceramic powder must have fluidity. On the other hand, a large amount of self-fusing alloy must be added. Therefore, if there is a difference in specific gravity between the ceramic particles and the self-fusing alloy, the wear-resistant powder will segregate, making it impossible to obtain a uniform composite layer. In other words, if the specific gravity of the ceramic powder is greater than the specific gravity of the self-fusing alloy, the ceramic powder will segregate on the inner wall of the cylinder, requiring a large amount of processing to obtain a composite layer, resulting in high processing costs and wasted material. On the other hand, if the specific gravity of the ceramic powder is lower than that of the self-fusing alloy, the ceramic powder will segregate toward the center of the cylinder, and as a result, the area made only of the self-fusing alloy will exhibit properties as a wear-resistant composite layer. Because there is no material, it is a waste of material.

However, this method had drawbacks such as not being able to provide a thin coating and having poor workability because it rotated hot red-hot parts.

[Purpose of the invention]

It is therefore a general object of the present invention to provide a coating method which obviates many of the drawbacks mentioned above and which makes it possible to form a segregation-free wear-resistant composite layer to the desired thickness.

[Key points of the invention]

In order to achieve this objective, in the method for manufacturing a wear-resistant composite layer according to the present invention, ceramic powder and an organic binder are mixed to form a slurry, the slurry is injected into the inner surface of a rotating cylinder, and the slurry is dried with ventilation while rotating. After that, the slurry obtained by mixing the metal powder and the organic binder is injected into the rotating cylinder and dried with ventilation while rotating to form a double layer of a predetermined thickness, and then heated to decompose and burn the organic binder component. The ceramic layer and the metal powder layer are completely removed by heating in a vacuum or in a non-oxidizing atmosphere to sinter the ceramic layer and the metal powder layer to form a uniform composite layer with excellent wear resistance. The following metal powders are used as the metal powder in the present invention.

(1) N1-based self-fusing alloy (CrO ~ 20%, B1,0
~5.0%, S11.5~5.0%, CI, 1% or less P
e 5% or less, balance Ni) (2) Cog self-fusing alloy (Cr 0-24%, B1,
0 to 5.0%, S11.5 to 5.0%, CI, 5% or less, k'e 5% or less, NfO to 33%, balance Co) or more, with a grain size of 150 mesh or less Use. The reason for using a self-fusing alloy is that its melting point is 900.
It has a relatively low melting point of ~1100°C, does not require a high-temperature furnace for sintering, has high viscosity during melting, has little deformation due to flow and sag during sintering, and has excellent wear resistance and durability. That is what we are doing.

Ceramic powders include WC and VC.

T, iB2. Use materials such as MoB, TiN, ZrN, etc. that have good compatibility with the molten metal powder. The particle size is approximately 1-100μ, and the hardness of these ceramics is Hv15.
00-3400 and has excellent wear resistance.

The organic binder is a viscous solution made by dissolving a natural or synthetic polymer compound in water or a volatile solvent, and is used to impart fluidity to powder particles when forming a ceramic layer or self-fusing alloy layer on the inner wall of a cylinder. used for Moreover, after drying of one layer, it acts as an adhesive between the powder particles and between the powder particles and the inner wall of the cylinder. The polymer compound is preferably one that completely decomposes and burns at as low a temperature as possible.

The mixing ratio of the polymer compound to water or volatile solvent in the organic binder is about 1 to 20% by weight. A preferable example of the mixing ratio of the polymer compound and the solvent is polyester urethane (8%)/methyl ethyl ketone ( 92%)
.

Polymethyl acrylate (13.5%)/Toluene (86%)
, 5%), polyvinyl alcohol (3%)/water (97%)
). The mixing ratio of the organic binder to the anti-wear powder is preferably about 0.1 to 5% by weight.

To attach the slurry to the inner wall of the cylinder, cover both ends of the cylinder with lids that have an opening in the center, and while rotating the cylinder, pour the ceramic slurry into a predetermined amount through a funnel through one opening, so that the slurry is sufficiently coated on the inner wall of the cylinder. When the self-fusing alloy slurry is evenly distributed, it is dried under rotating ventilation, and then the self-fusing alloy slurry is poured in. When the self-fusing alloy slurry is sufficiently evenly distributed on the ceramic layer, it is dried under rotating ventilation.

The dry slurry layer is heated in order to decompose, burn, and gasify the polymer compound component of the organic binder used as a binder for the ceramic powder and the self-fusing alloy powder. Approximately 3
The process is carried out at 00 to 750°C until complete gasification. If the polymer compound remains undecomposed, it will contaminate the inside of the sintering furnace in the next process.
It also causes the formation of pores in the wear-resistant composite layer.

The purpose of the subsequent heating in a vacuum and non-oxidizing atmosphere is to sinter the ceramic powder and the self-fusing alloy powder, and the temperature is 50 to 200°C higher than the melting point of the self-fusing alloy, about 100°C.
It is carried out at 0 to 1600°C. In order to prevent the self-fusing alloy and ceramic powder from being oxidized and decarbonized, the process is carried out in a vacuum or in a non-oxidizing atmosphere. At this temperature, the self-fusing alloy melts and penetrates into the WC layer, and liquid phase sintering occurs between the two. As a result, ceramic powder with excellent wear resistance is uniformly distributed in the self-fusing alloy as a matrix. A composite layer is formed with a distribution of At the same time, a diffusion layer is formed between this composite layer and the cylinder inner wall (base material), resulting in a coating layer with excellent adhesion strength.

[Embodiments of the invention]

Next, the present invention will be specifically explained with reference to Examples.

The compositions of the self-fusing alloy and organic binder used in the examples are shown below.

Example 1 WC powder with an average particle size of 10 μm was mixed with an organic powder (ind.
3-5) A lid body 14.2 is mixed with 10m/ml to form a ceramic slurry, and as shown in FIG. i4 was attached, a funnel 16 was inserted through the opening 12 of one lid 14, and the slurry 18 was poured into the cylinder 10 through the funnel 16 while rotating the cylinder 10 at about 50 rpm. Thereafter, air was blown into the cylinder 10 while continuing one revolution to dry the slurry 18 for 30 minutes, thereby forming a ceramic layer 20. Next, a self-fusing alloy powder (Ni-2) 21& with a particle size of 250 mesh or less is mixed with an organic binder (B-
3) mixed with 250d to obtain self-fusing alloy slurry 22,
The funnel 1 was rotated 100 times in the same manner as above.
Ceramic layer 200 on the inner surface of the cylinder 10 via 6
The slurry was poured onto the surface and then blown with air to dry the slurry for 30 minutes to form a uniform self-fusing alloy layer 24 (second
(see figure). Thereafter, natural drying was performed for 14 hours to completely dry the film.

Thereafter, the cylinder 10 was held at 400° C. for 60 minutes in the atmosphere to completely decompose and burn the polyvinyl alcohol.

Next, the mixture was heated in a vacuum furnace at 1100° C. for 60 minutes while being kept still, and then cooled in the furnace.

It was taken out of the furnace at a temperature below 200°C and air cooled to room temperature.

When the cross section of the obtained composite layer was observed using a micrograph, it was found that the WC particles 26 were uniformly dispersed in the matrix of the N1-based self-fusing alloy 28, as shown in FIGS. 3 and 4. No segregation was observed. In addition, the thickness of the composite layer is 1.0 mm, and the hardness is Hv 830-132.
0, and the diffusion layer 62 formed between it and the base material 30 (80M435) had a thickness of about 25μ, confirming that it was firmly bonded to the base material. Furthermore, the WC content of the composite layer at this time was about 62% by weight.

Example 2 The organic binder of the WC slurry was (B-2), and a self-fusing alloy (Ni-13 was used, organic) (inder (B-2) was used).
-2) Except that it was made into a slurry, the process was carried out in exactly the same manner as in Example 1 to obtain a composite layer having exactly the same properties except for the hardness of the composite layer of Hv 700 to 1250.

Example 3 The organic binder of the WC slurry was (B-1), a self-fusing alloy (Co-1) was used, and the organic binder (41
The process was carried out in the same manner as in Example 1 except that it was made into a slurry in step 3-1) to obtain a composite layer having exactly the same properties as in Example 1 except for the hardness of the composite layer of Hv 700 to 1200.

According to the present invention, it is possible to easily obtain a particularly thin composite layer of a desired thickness, which prevents segregation of wear-resistant powder, on the inner wall of the cylinder without rotating the cylinder by heating it to red.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various changes can be made without departing from the spirit of the invention.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of adding WC slurry while rotating the cylinder in Example 1 of the present invention, Figure 2 is an explanatory diagram of adding self-fusing alloy powder slurry, and Figure 3 is Example 1 of the present invention. Micrograph of the cross section of the composite layer obtained in (X20
0) and its explanatory diagram, FIG. 4, are also copies X (X100). 10... Cylinder 12... Opening 14... Lid
Body 16...Funnel 18..., WCC powder silica 11-20...Ceramic layer 22...Self-fusing alloy slurry 24...Self-fusing alloy layer 26...WC particles 28...Ni Base self-fusing alloy patent senryu (Toshiba Machine Co., Ltd. dispatcher et al. Patent attorney Hama 1) JiβitFl (3,
1 FIG, 3 200 FIO, 4 (3z) Procedural Amendment Form February 8, 1980 Commissioner of the Patent Office Kazuo Wakasugi I. 1. Indication of the case 1982 Patent Application No. 196167 2. Name of the invention Method for manufacturing a wear-resistant composite layer 3. Person making the amendment Relationship to the case Patent applicant address 4-2-11 Ginza, Chuo-ku, Tokyo Name (345
) Toshiba Machine Co., Ltd. representative plate material Kazuo 4, agent 6, subject of amendment (1) Brief explanation of drawings in the specification. 7. Contents of amendment +11 yi+as stated. Japanese Patent Application No. 58-196167, amended specification, page 14, lines 5 to 8, “Figure 3 is...” was changed to “Figure 3 is obtained in Example 1 of the present invention.” Micrograph (x200) of the cross section of the crystal structure of the composite layer and its explanatory diagram, No. 4
The figure is a micrograph (X100) of a cross section of the crystal structure of the same composite layer as in Figure 3. ” and correct it. Patent applicant: Toshiba Machine Co., Ltd.

Claims (1)

[Claims] (1) Ceramic powder and organic binder are mixed to form a slurry, this slurry is injected into the inner surface of a rotating cylinder and dried with ventilation while rotating, and then the metal powder and organic binder are mixed. The slurry is injected into the rotating cylinder and dried under rotation with ventilation to form a double layer of a predetermined thickness, and then heated to completely remove the organic binder component by decomposition and combustion, and then heated in a vacuum or in a non-oxidizing atmosphere. At the same time, the ceramic layer and the metal powder layer are heated to form a uniform composite layer in which the ceramic layer and the metal powder layer are sintered, and at the same time, the entire uniform composite layer is formed in which this composite layer and the inner surface of the cylinder are integrally bonded via a diffusion layer. 7. A method for producing a wear-resistant composite layer, characterized by: (2) Ceramic powder is metal carbide such as WC, VC, Tit32. Metal borides such as Mo8, TiN. The method for producing a wear-resistant composite layer according to claim 1, characterized in that the powder is selected from the group consisting of metal nitrides such as ZrN, or mixtures thereof. (6) The method for manufacturing a wear-resistant composite layer according to claim 1, wherein the metal powder is a Ni-based self-fusing alloy powder or a CO-based self-fusing alloy powder. (4) The method for producing a wear-resistant composite layer according to claim 1, wherein the organic binder comprises a solution of a natural or synthetic polymeric substance in water or a volatile organic solvent.