JPH0790414A - Ti-Al intermetallic compound intake / exhaust valve having excellent wear resistance and method of manufacturing the same - Google Patents

Abstract

(57) [Abstract] [Purpose] Ti-, which has excellent wear resistance, can improve the wear resistance of required parts without causing defects such as cracking and without reducing productivity. To provide an intake / exhaust valve made of an Al-based intermetallic compound and a method for manufacturing the same. To provide a method of joining with. [Structure] Al: 35-50 at%, and a Ti-Al-based intermetallic compound produced by synthesizing a mixed powder of Ti and Al having a composition of the balance Ti by reaction sintering,
TiB ₂ , Al ₂ O ₃ , ZrO ₂ , Si having an average particle size of 0.5 to 20 μm and a total volume ratio of 0.5 to 30% on one or more of the face, stem, and stem end of the intake and exhaust valves.
Ti, which has excellent wear resistance, is characterized by containing one or more ceramic particles of C, TiC, WC, and Si ₃ N _4.
-Al-based intermetallic compound intake / exhaust valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake / exhaust valve which is required to be lightweight, has high temperature strength, high specific rigidity and wear resistance in an internal combustion engine in the field of automobiles and the like, and more specifically to wear resistance. The present invention relates to a Ti-Al intermetallic compound intake / exhaust valve excellent in heat resistance and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of environmental protection and energy saving,
Attention has been focused on reducing the weight of automobile members, and in particular, the conversion from conventional iron-based members to lightweight aluminum-based members is under consideration. However, there are many sliding members for automobile members, especially for members around the engine, and when a part of the members is replaced with an iron-based member, it is often worn and becomes a practical problem. Therefore, the appearance of a member that is lightweight and has excellent wear resistance is awaited.

From this point of view, the Ti-Al intermetallic compound, which is light in weight and excellent in strength and heat resistance, is expected to be applied to automobile members, and is being studied for sliding members used at high temperatures. is there. In particular, the face face, stem end, and stem side face of the valve are the parts where friction with other members occurs, so wear resistance is required, but conventional Ti-Al-based members do not have sufficient wear resistance. , Some sort of improvement was needed.

Generally, the Ti-Al intermetallic compound is often produced by a melting method such as plasma arc. As shown in Sumitomo Light Metal Technical Report, Vol. 32 (1991) p.95,
It can also be produced by a reaction sintering method using Ti powder and Al alloy powder as raw materials. According to this reaction sintering method,
Since it is possible to disperse particles such as ceramic particles in the material, in order to improve the strength of the Ti-Al-based intermetallic compound, a method of dispersing hard particles such as ceramic particles in the material is "Excellent TiAl-based composite material and method for producing the same"
No. 2 publication.

[0005]

However, in the technique described in the above publication, attention is not paid to the wear resistance, and this technique has an advantage that the strength is improved. Since the particles are contained, the room temperature ductility may be deteriorated and the toughness, which is the original characteristic of the valve, may be impaired. In addition, since a member containing ceramic particles is generally more difficult to cut than a member not containing ceramic particles, there is a problem that it is difficult to finish the valve.

As a countermeasure against this, a composite intermetallic compound in which ceramic particles are dispersed is made to exist only in the frictional portions of the valve (face surface, stem end, stem side surface) without impairing the toughness inherent to the valve. To
It has been considered to improve the wear resistance of the valve. For example, add particles only to the parts of the valve where wear resistance is required,
As a method of precipitation, Japanese Patent Laid-Open Nos. 62-611, 3-180479 and 3-215654 are available.
The technique described in the publication is known.

However, since these are all melting processes such as padding, they cannot be used for the purpose of the present invention. That is, when a material having low ductility such as Ti-Al system is subjected to a treatment involving partial melting such as build-up, there is a problem that cracks easily occur due to internal stress generated during solidification contraction. In order to prevent this, sufficient preheating, post-heating and the like are required, which causes another problem that productivity is remarkably reduced, which is not preferable.

The present invention has been made to solve the above problems, and can improve the wear resistance of a required portion without causing defects such as cracking and without lowering productivity. An object is to provide a Ti—Al-based intermetallic compound intake / exhaust valve having excellent wear resistance and a method for manufacturing the same.

[0009]

In order to achieve the above object, the invention of claim 1 is a Ti- produced by synthesizing a mixed powder of Ti and Al containing 35 to 50 at% of Al by reaction sintering. It is made of Al-based intermetallic compound, and has an average particle size of 0.5 to 20 μm and a total volume ratio of 0.5 to 3 at one or more of the face, stem and stem end of the intake and exhaust valves.
0% TiB ₂ , Al ₂ O ₃ , ZrO ₂ , SiC, TiC,
A gist is a Ti—Al-based intermetallic compound intake / exhaust valve having excellent wear resistance, which is characterized by containing at least one kind of ceramic particles of WC and Si ₃ N ₄ .

According to a second aspect of the present invention, the mixed powder of the first aspect further comprises Mn in an amount of 0.05 to 5 at%, which is made of a Ti-Al-based intermetallic compound having excellent wear resistance. The gist is the exhaust valve.

According to a third aspect of the present invention, titanium powder and Al powder or Al-Mn alloy powder are used for Al; 35 to 50 at% and the balance Ti, or Al; 35 to 50 at%, Mn; 0.0.
5 to 5 at% and the balance Ti so as to have a composition, and after solidifying and molding the mixed powder, forging or cutting to form a substantially valve-shaped first member, and the powder used as the mixed powder, Average particle size 0.5 to 20 μm and total volume ratio 0.5
30% of _{TiB 2, Al 2 O 3,} ZrO 2, SiC, Ti
C, WC, Si ₃ N ₄ is mixed with at least one kind of ceramic particles, and the ceramic mixed powder is solidified and molded, and then forged or cut to form a second member having a predetermined shape to supplement the first member, A method for manufacturing a Ti-Al-based intermetallic compound intake / exhaust valve having excellent wear resistance, characterized in that the first member and the second member are combined and heat-treated for reactive sintering. And

Here, the heat treatment for carrying out the reactive sintering is a treatment for reacting Ti and Al to form homogeneous TiAl, and usually, it is 5 at a pressure of 30 MPa or more.
The reaction is carried out at 60 ° C. and then homogenized at a temperature of 1170-1400 ° C. Next, the reason for limiting the numerical values in the claims will be described.

(1) Ceramic Particle Size If the particle size is less than the lower limit, wear resistance is not sufficient. If the upper limit is exceeded, processing becomes difficult. (2) Amount of added ceramic particles If the amount is less than the lower limit, the wear resistance is insufficient. If the upper limit is exceeded, processing becomes difficult.

(3) Amount of Al If the amount is less than the lower limit value, the wear resistance decreases. If it exceeds the upper limit, the ductility decreases. (4) Amount of Mn The ductility of the Ti-Al-based intermetallic compound is improved by adding Mn.
Ordered Intermetallic compound III, MRS, 133 (1
989), p.391 ". If it is less than the lower limit, there is no improvement effect on ductility. If it exceeds the upper limit, the ductility decreases and the density increases.

[0015]

According to the invention of claim 1, in consideration of the finding that the wear resistance is improved by adding ceramic particles to the lightweight Ti-Al intermetallic compound, the wear resistance of the intake / exhaust valve is required to be increased. The particle diameter of the ceramic particles and the addition amount of the ceramic particles within the above range are included.
This makes it possible to obtain a valve with improved wear resistance without unnecessarily reducing the machinability while ensuring the toughness that is the original property of the valve.

According to the invention of claim 2, a predetermined amount of Al and T
Since a mixed powder containing a predetermined amount of Mn in addition to i is used, the ductility is improved. According to the invention of claim 3,
A substantially bulb-shaped first member is formed using a mixed powder of titanium powder and Al powder or Al-Mn alloy powder,
Further, a second member is formed by using a ceramic mixed powder obtained by mixing the powder used as the mixed powder and ceramic particles, and the first member and the second member are combined and heated at a predetermined temperature under a predetermined high pressure. In other words, the base Ti-
Since the heat treatment for reaction sintering is performed in a state where the first member made of Al and the second member containing ceramics are integrated by, for example, fitting, an intake / exhaust valve in which desired portions contain ceramic particles is manufactured. The method of doing is simplified.

[0017]

EXAMPLES Next, examples of the present invention will be described. Example 1 A sponge titanium powder (149 μm or less) produced by the Na method and an Al-7 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomizing method were mixed in a mass ratio of 64:36, Dimensions φ200 mm x φ19
Insert into a 0 mm x 500 mm L aluminum container and evacuate while heating the container to 500 ° C to 1.3 x 10 ^-3 Pa.
Degassing treatment was performed in vacuum. Then, the container is 430 ℃
And extruded to φ37 mm. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. This is Ti-33.5mass% Al-2.
5 mass% Mn (Ti-47.3 at% Al-1.7 at% Mn)
Material for reaction synthesis (hereinafter referred to as Material A).

On the other hand, after sponge titanium powder (149 μm or less) produced by the Na method and Al-7 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed in a mass ratio of 64:36, Average particle size of 5μ
25% by volume of TiB ₂ particles of m were mixed. The mixed powder was inserted into an aluminum container dimensions φ200mm × φ190mm × 500mmL, evacuated to 1.3 × 10 while heating the vessel to 450 ° C. ^- was ³ Pa degassed in a vacuum of. Then, the container was heated to 450 ° C. and extruded to φ40 mm. The aluminum container was removed from the obtained extruded material, and the extruded material was cut as shown in FIG. 1 (b) to obtain (Ti-33.
A composite material for reactive synthesis of 5 mass% Al-2.5 mass% Mn) +25 vol% TiB ₂ (hereinafter referred to as material B) was used.

Next, as shown in FIG. 1 (c), a material B was fitted into the material A to prepare a combination material (hereinafter referred to as material C). And this material C is 80Mp in HIP.
Reaction sintering (560 ° C.) was carried out while increasing the temperature under the Ar gas pressure of a to form an intermetallic compound, and subsequently 1 in HIP.
A heat treatment for homogenization was performed at 300 ° C. for 10 hours. During the homogenization treatment, the atmosphere was Ar gas and the pressure was 180 MPa. After that, the exhaust valve was finished by cutting. In the finished valve, the surfaces of the face, the side surface of the stem, and the stem end were intermetallic compounds containing ceramic particles.

(Experimental Example) Next, an experimental example using the valve of the first embodiment will be described. The valve of Example 1 was subjected to an engine test, and the amount of wear on the face surface, the stem side surface, and the stem end after the test was performed at 10,000 rpm for 2 hours was measured. In addition, the amount of wear of the current material (Comparative Example sample No. 9; SUH35) that was subjected to the same engine test as a comparative material was set to 1 and compared. The results are shown in Table 1 below together with the composition of the material B, and those having a wear amount equal to or less than the current material are good materials. Further, at the time of forming the material B, a φ5 mm × 8 mm test piece was cut and subjected to a room temperature compression test. The results are also shown in Table 1.

As is clear from this experiment, Example 1 is preferable because the room-temperature compression elongation is as large as 13% and the wear amount is 1.0 or less, which is less than the current material. [Example 2] Titanium sponge powder (149 µm or less) produced by the Na method and Al-7mass% Mn alloy powder (149 µm or less) produced by the Ar gas atomization method were mixed in a mass ratio of 73:27. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, after sponge titanium powder (149 μm or less) produced by the Na method and Al-7mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomizing method were mixed in a mass ratio of 73:27, Average particle size 2μ
5% m ₂ Al ₂ O ₃ particles were mixed by volume. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Material C was subjected to reaction sintering in HIP under a pressure of 50 Mpa, followed by heat treatment in HIP at 1250 ° C. to carry out the same experiment as in Example 1. The results are shown in Table 1. As is clear from this experiment, Example 2
The room temperature compression elongation is as large as 18%, and the wear amount is 0.9 or less, which is less than the current material, which is preferable.

[Example 3] Titanium powder (149 µm or less) produced by the hydrodehydrogenation method and Al powder (149 µm or less) produced by the air atomization method were used in a mass of 6
Mixed in a ratio of 4:36. Then, as in Example 1,
The mixture was placed in an aluminum container, degassed, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, a sponge titanium powder (149 μm or less) produced by the Na method and an Al powder (149 μm or less) produced by the Ar gas atomizing method are mass 64: 3.
After mixing at a ratio of 6, TiC particles having an average particle size of 2 μm were mixed at 5% by volume. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1, and the same experiment was conducted. The results are shown in Table 1. As is clear from this experiment, Example 3
Has a large room-temperature compressive elongation of 25% and wear amount of 0.
It is preferable since it is 8 or less and the current material or less.

Example 4 A titanium powder (149 μm or less) produced by the hydrodehydrogenation method and an Al powder (149 μm or less) produced by the air atomization method were mixed in a mass of 7
Mixed in a ratio of 3:27. Then, as in Example 1,
The mixture was placed in an aluminum container, degassed, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, sponge titanium powder (149 μm or less) produced by the Na method and Al powder (149 μm or less) produced by the Ar atomizing method were mixed at a ratio of 73:27 by mass, and then the average particle diameter was added to the mixture. 10 μm SiC particles were mixed by 10% by volume. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and the heat treatment were carried out in HIP in the same manner as in Example 1, and the same experiment was conducted. The results are shown in Table 1. As is clear from this experiment, Example 4
Has a large room-temperature compressive elongation of 20% and has a wear amount of 1.
It is preferable because it is 0 or less and the current material or less.

Example 5 A sponge titanium powder (149 μm or less) produced by the Na method and an Al-7 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed in a mass ratio of 64:36. did. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, after sponge titanium powder (149 μm or less) produced by the Na method and Al-7mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed in a mass ratio of 64:36, Average particle size of 1μ
2% by volume of ZrO ₂ particles of m were mixed. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1, and the same experiment was conducted. The results are shown in Table 1. As is clear from this experiment, Example 5
Has a large room-temperature compressive elongation of 22% and a wear amount of 1.
It is preferable because it is 0 or less and the current material or less.

Example 6 A sponge titanium powder (149 μm or less) produced by the Na method and an Al-7 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomizing method were mixed at a mass ratio of 64:36. Mixed. Then, as in Example 1, the mixture was inserted into an aluminum container,
After degassing, extrusion was performed. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, after sponge titanium powder (149 μm or less) produced by the Na method and Al-7 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed in a mass ratio of 64:36, The average particle size is
8 μm WC particles were mixed by 1% by volume. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Hereinafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1, and the same experiment was performed. The results are shown in Table 1. As is clear from this experiment, Example 6
Has a large room-temperature compressive elongation of 20% and has a wear amount of 0.
It is preferable since it is 8 or less and the current material or less.

Example 7 A sponge titanium powder (149 μm or less) produced by the Na method and an Al-7mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed at a mass ratio of 64:36. Mixed. Then, as in Example 1, the mixture was inserted into an aluminum container,
After degassing, extrusion was performed. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, after sponge titanium powder (149 μm or less) produced by the Na method and Al-7mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed in a mass ratio of 64:36, Average particle size of 15
8 μm volume Si ₃ N ₄ particles were mixed. Then, as in Example 1, the mixture was inserted into an aluminum container,
After degassing, extrusion was performed. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Hereinafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1, and the same experiment was performed. The results are shown in Table 1. As is clear from this experiment, Example 7
Has a large room-temperature compressive elongation of 15% and a wear amount of 0.
It is preferable since it is 8 or less and the current material or less.

[Embodiment 8] Titanium sponge powder (149 μm or less) produced by the Na method and Al-17 mass% Mn alloy powder (149 μm) produced by the Ar gas atomization method.
And the following) in a mass ratio of 57:43. afterwards,
In the same manner as in Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, sponge titanium powder (149 μm or less) produced by the Na method and Al-17 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method.
And are mixed in a mass ratio of 57:43, and then mixed with an average particle size of 1
0 μm SiC particles were mixed by 10% by volume. afterwards,
In the same manner as in Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and heat treatment were carried out in HIP in the same manner as in Example 1, and the same experiment was conducted. The results are shown in Table 1. As is clear from this experiment, Example 8
Has a large room-temperature compressive elongation of 15% and a wear amount of 0.
It is suitable because it is 9 or less and the current material or less.

[0042]

[Table 1]

That is, as is apparent from Table 1, it is preferable that the room temperature compressive elongation showing ductility is 10% or more. However, in all of Examples 1 to 8, the room temperature compressive elongation is 13% or more. Great and excellent. Moreover, as for the wear resistance, the wear amount of each of the present examples is smaller than that of the current material, and thus it is suitable. In addition, since Example 8 has a high Mn content and thus is excellent in ductility, the effect is saturated even if Mn in excess of 5 at% is added, so the addition amount may be small.

[Comparative Example 1] A sponge titanium powder (149 μm or less) produced by the Na method and an Al powder (149 μm or less) produced by the Al gas atomizing method were mixed in a mass of 7
Mixed in a ratio of 8:22. Then, as in Example 1,
The mixture was placed in an aluminum container, degassed, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, a sponge titanium powder (149 μm or less) produced by the Na method and an Al powder (149 μm or less) produced by the Ar gas atomizing method are 78: 2 by mass.
After mixing at a ratio of ₂ , 25% by volume of TiB ₂ particles having an average particle size of 5 μm were mixed. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1 and the evaluation was performed. The results are shown in Table 2 below. In Comparative Example 1, the elongation was low because the amount of Al was low. [Comparative Example 2] Titanium sponge powder (149 µm or less) produced by the Na method and Al powder (149 µm or less) produced by the Ar gas atomizing method were mixed in a mass ratio of 62:38. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, a sponge titanium powder (149 μm or less) produced by the Na method and an Al powder (149 μm or less) produced by the Ar gas atomizing method are mass 62: 3.
After mixing at a ratio of 8, Al ₂ O ₃ particles having an average particle diameter of 2 μm were mixed at 5% by volume. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and the heat treatment were carried out in HIP in the same manner as in Example 1 and subjected to the evaluation. The results are shown in Table 2.
In Comparative Example 2, the elongation was low because the Al content was high. Comparative Example 3 A sponge titanium powder (149 μm or less) produced by the Na method and an Al-7 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed in a mass ratio of 64:36. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, after sponge titanium powder (149 μm or less) produced by the Na method and Al-7mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomizing method were mixed in a mass ratio of 64:36, Average particle size of 5μ
m TiB ₂ particles were mixed by 0.3% by volume. Then, as in Example 1, the mixture was inserted into an aluminum container,
After degassing, extrusion was performed. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1 and the evaluation was performed. The results are shown in Table 2.
In Comparative Example 3, the amount of particles added was small and the wear resistance was poor. [Comparative Example 4] A sponge titanium powder (149 µm or less) produced by the Na method and an Al-7mass% Mn alloy powder (149 µm or less) produced by the Ar gas atomization method were used in a mass ratio of 67.7: 32.3. Mixed. Then, Example 1
Similarly to the above, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, a sponge titanium powder (149 μm or less) produced by the Na method and an Al-7 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomizing method were used in a mass ratio of 67.7: 32.3. After mixing, 33% by volume of TiB ₂ particles having an average particle size of 5 μm were mixed. afterwards,
In the same manner as in Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1 and the evaluation was performed. The results are shown in Table 2.
However, in Comparative Example 4, the amount of particles added was too large to perform cutting. [Comparative Example 5] A sponge titanium powder (149 µm or less) produced by the Na method and an Al-7mass% Mn alloy powder (149 µm or less) produced by the Ar gas atomization method were used in a mass ratio of 67.7: 32.3. Mixed. Then, Example 1
Similarly to the above, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, a sponge titanium powder (149 μm or less) produced by the Na method and an Al-7 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomizing method were used in a mass ratio of 67.7: 32.3. After mixing, 20% by volume of TiB ₂ particles having an average particle size of 25 μm were mixed. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1 and the evaluation was performed. The results are shown in Table 2.
However, in Comparative Example 5, the added particle size was large and the cutting process could not be performed. Comparative Example 6 Titanium sponge powder (149 μm or less) produced by the Na method and Al-7mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed in a mass ratio of 64:36. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material and cut into a valve shape shown in FIG. 1 (material A).

On the other hand, after sponge titanium powder (149 μm or less) produced by the Na method and Al-7mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed in a mass ratio of 64:36, The average particle size is
2 μm Si ₃ N ₄ particles were mixed by 10% by volume. Then, like Example 1, the mixture was inserted into an aluminum container, deaerated, and then extruded. The aluminum container was removed from the obtained extruded material, cut and processed to prepare a composite material for reaction synthesis (material B), which was combined with material A to prepare material C.

Thereafter, the reaction sintering and the heat treatment were carried out in HIP in the same manner as in Example 1 and the evaluation was carried out. The results are shown in Table 2.
In Comparative Example 6, the added particle size is small and the wear resistance is poor. [Comparative Example 7] A sponge titanium powder (149 µm or less) produced by the Na method and an Al-7mass% Mn alloy powder (149 µm or less) produced by the Ar gas atomization method were used in a mass ratio of 67.7: 32.3. After mixing, add an average particle size of 2μ
5% m TiB ₂ particles were mixed by volume. This mixed powder was inserted into an aluminum container in the same manner as in Example 1, and the container
The degassing treatment was performed in the same manner as in Example 1 while heating at 50 ° C. Then, the container was heated to 450 ° C. and extruded to φ40 mm. The aluminum container was removed from the obtained extruded material and cut into a valve shape.

Thereafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1 and the evaluation was performed. The results are shown in Table 2.
Note. In Comparative Example 7, since the whole particle-added composite material was used, the stem portion which was considered to have insufficient toughness was broken 3 minutes after the engine test was started, and the wear resistance could not be evaluated.

[Comparative Example 8] A sponge titanium powder (149 μm or less) produced by the Na method and an Al-7 mass% Mn alloy powder (149 μm or less) produced by the Ar gas atomization method were mixed at a mass ratio of 64:36. Mixed. This mixed powder was inserted into an aluminum container in the same manner as in Example 1, and was degassed in the same manner as in Example 1 while heating the container to 500 ° C. Then, the container was heated to 430 ° C. and extruded to φ37 mm. The aluminum container was removed from the obtained extruded material and cut into a valve shape.

Thereafter, the reaction sintering and the heat treatment were performed in HIP in the same manner as in Example 1 and the evaluation was performed. The results are shown in Table 2.
Note. This Comparative Example 8 was inferior in wear resistance because the whole was not added with particles. [Comparative Example 9] This comparative example 9 is an iron-based SU which is the current material.
Since it is made of H35, it is excellent in compressive elongation, but is heavier than the Ti-Al system.

[0060]

[Table 2]

Although the embodiments of the present invention have been described above, the present invention is by no means limited to such embodiments, and it goes without saying that the present invention can be implemented in various modes. For example, the ceramic particles may be mixed at the same time as the Ti—Al-based material powder is mixed.

[0062]

According to the first aspect of the present invention, since the portion of the intake / exhaust valve where wear resistance is required contains the ceramic particles of a predetermined particle size and addition amount, while maintaining the original toughness of the valve. The wear resistance can be improved without reducing the machinability.

According to the invention of claim 2, a predetermined amount of Al and T
Since a predetermined amount of Mn is contained in addition to i, there is an advantage that ductility is improved. According to the third aspect of the present invention, the Ti—Al-based first member serving as the base and the second member including the ceramics are subjected to heat treatment in order to react and sinter. It is possible to easily manufacture an intake / exhaust valve having excellent wear resistance. Further, according to this manufacturing method, there is a feature that defects such as cracks do not occur and the productivity is high.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a method of manufacturing a valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kim Jun Atsushi 5-11-3 Shimbashi, Minato-ku, Tokyo Within Sumikari Light Metal Industry Co., Ltd. (72) Inventor Hiroyuki Ichimoto 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Takashi Morikawa 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation

Claims (3)

[Claims] 1. A T produced by synthesizing a mixed powder of Ti and Al containing 35 to 50 at% of Al by reaction sintering.
It is made of i-Al intermetallic compound, and has a total volume ratio of 0.5 to 30% with an average particle diameter of 0.5 to 20 μm at one or more of the face, stem and stem end of the intake and exhaust valves.
iB ₂ , Al ₂ O ₃ , ZrO ₂ , SiC, TiC, WC, S
An intake / exhaust valve made of a Ti—Al-based intermetallic compound having excellent wear resistance, which comprises one or more ceramic particles of i ₃ N ₄ . 2. The mixed powder according to claim 1, further comprising M
An intake / exhaust valve made of a Ti-Al-based intermetallic compound having excellent wear resistance, characterized by containing n in an amount of 0.05 to 5 at%. 3. Composition of titanium powder and Al powder or Al-Mn alloy powder, Al; 35-50 at% and balance Ti, or Al; 35-50 at%, Mn; 0.05-5 at% and balance Ti. And the mixture powder is solidified and molded, and then forged or cut to form a substantially valve-shaped first member, and the powder used as the mixed powder and an average particle diameter of 0.5 to 20 μm. Ti with a total volume ratio of 0.5 to 30%
B ₂ , Al ₂ O ₃ , ZrO ₂ , SiC, TiC, WC, Si
_After mixing one or more kinds of ₃ N ₄ ceramic particles and solidifying and molding the ceramic mixed powder, the mixture is forged or cut to form a second member having a predetermined shape to supplement the first member. A method of manufacturing a Ti-Al intermetallic compound intake / exhaust valve having excellent wear resistance, which comprises performing heat treatment for performing reactive sintering in combination with a second member.