JPH03287702A - Manufacture of aluminide-made inlet and exhaust valve for internal combustion engine - Google Patents

Abstract

PURPOSE:To easily manufacture an inlet and exhaust valve having complicate shape by extruding a billet composed of the mixed material of Ti powder or Fe powder or Ni powder and Al powder for raw material to make the valve shape and executing reaction sintering to this. CONSTITUTION:The Ti powder or Fe powder or Ni powder and Al (alloy) powder for raw material of aluminide, are mixed so as to become composition in the inequalities I and II. The mixed material is cut after making hard in hot or cold state to make the billet. By extruding the billet, valve shape or pseudo valve shape composed of non-extruding part as face part and extruded part as stem part, is formed. By executing heat treatment to this shaped body, the reaction sintering is executed and after that, cutting work, etc., is executed to make the desired inlet and exhaust valve for internal combustion engine. By this method, the valve having complete shape can be manufactured and excellent strength, ductility, heat resistance and oxidizing resistance can be given.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing aluminide intake and exhaust valves for internal combustion engines.

[Prior Art] Conventionally, many aluminide products are generally cast products, but those with complex shapes that are difficult to cast or those with thin parts such as valve stems have been manufactured by machining.

[Problems to be Solved by the Invention] However, when machining an aluminide engine valve or the like having a complicated shape, a large amount of cutting waste is generated, resulting in poor production yield and high manufacturing cost. Furthermore, since aluminide is hard, it is difficult to cut.

This invention is extremely easy to manufacture even if it has a complicated shape, and is also a low-cost aluminide intake for internal combustion engines.
The objective is to provide methods for manufacturing and using exhaust valves.

[Technical means for solving the problems] In order to solve the above problems, this invention uses Ti powder, Fe powder, or Ni powder, which are raw materials for aluminide, and Al powder or A powder.
A step of mixing l alloy powder with the following composition to form a mixture,
A step of hardening this mixture hot or cold and then cutting it into a predetermined length to create a billet for extrusion; and a step of extruding this billet to form an unextruded part that will become the face part of the valve;
The process consists of a step of forming a valve-shaped body or pseudo-valve-shaped body consisting of an extruded portion that becomes the stem portion of the valve, and a step of reaction-sintering this valve-shaped body or pseudo-valve-shaped body.

25at%≦Ti or Fe or Ni≦75at%25a
t%≦Al or Al alloy≦758t% [Function] 25at%≦TI or Fe or Ni≦75at%25a
A mixture with a composition of t%≦Al or Al alloy≦75 at% is hardened hot or cold, then cut into predetermined lengths to make a billet for extrusion, and when extruding this billet, a portion is pressed. A valve-shaped body or pseudo-valve-shaped body is made with the remaining part used as the face part of the valve and the extruded part used as the valve stem part, and this valve-shaped body or pseudo-valve-shaped body is reacted and sintered to form aluminide. Intake and exhaust valves for internal combustion engines are obtained.

[Examples] Examples of the present invention will be described below along with drawings used for carrying out the invention. In Figure 1.2, 1 is a cylindrical container, 2 is a die that can be slid inside the container 1, 3 is a push plate fixed at the bottom of the container 1, and 4 is a pusher that pushes the die 2 downward. The push rods for each are shown. The inner diameter of the container 1 is set to 30φ. The die 2 includes a recess 2a having a contour corresponding to the face of an intake and exhaust valve for an internal combustion engine, and a circular hole 2C communicating with the recess 2a through a communication hole 2b. The diameter of the communication hole 2b is 6
It is φ. The lower part 4a of the push rod 4 is cylindrical and comes into contact with the upper surface 2d of the circular hole 2C of the die 2.

Example 1 Ti-47A Example 2 Ti-48A Example 3 Fe-40△ Example 4 Ni-25A 30φX20h ( A short cylindrical mixture 5 having dimensions h (height) is placed between the die 2 and the push plate 3 as shown in FIG. Push the die 2 downward and unload it when the distance between the upper surface of the push plate 3 and the lower end of the die 2 is 5M.

As a result, a portion of the mixture 5 extends upward through the communication hole 2b and forms the stem portion of the valve. The remainder of the mixture 5 is formed in the stem of the valve by the recess 2a of the die 2. This charged material 6 was taken out from the container 1 and subjected to the heat treatment shown in Table 1 (pre-diffusion treatment in vacuum, reaction sintering at 150 °C).
After performing HIP in 0 atm Ar gas and homogenization treatment in vacuum) to form aluminide, 3Mn 2V 13 was cut into the desired valve shape. Table 1 shows the heat treatment conditions of each example and comparative examples.

In the above embodiments, the Al alloy may contain one or more of the following as components (at%), and the remainder may be A.

Cr...0.05~10 Mn・0.05~10 ■...0.05~10 Co...0.05~10 Zr...0.05~10 Y...0.05~10 Mo...0.05~10 Nb ...0.05-10 Hf...0.05-10 Ta...0.01-10 W...0.01-10 Ce...0.01-'10 Nd...0.01-10 Si...09001-10 B...0 .01~5.0 C...0.001~5. O N...0.001~5.0 0...0.01~1.0 When producing aluminide, the following should be noted regarding each of the above components: (a) 25 at% unvortexed for Al, Ti, Fe, and N or if it exceeds 75 at%, the alloy will not react,
It is difficult to form it into an intermetallic compound.

(b) Or for Cr, Mn, B, C, and N, Mn is less than 0.05 at%, B is less than 0.01 at%, C, N
If the content is less than 0.001 at%, no improvement in ductility is observed.

Also, Cr and Mn are 10 at%, and B, C, and N are 5. Qat
%, the improvement in ductility becomes saturated.

(C>W, Si) If W is less than 0.01 at% and 3i is less than 1 at% of O,0O, no improvement in oxidation resistance is observed, and if W or Si exceeds 10 at%, the oxidation resistance is saturated.

(d) Co, Zr, Y, Mo5Nb, Hf, Ta.

Regarding Ce and Nd, no improvement in strength is observed when Co, Zr, Y, Mo, Nb, and Hf are less than 0.05 at%, Ta, Ce, and Nd are less than 0.018 t%, and multi-elements are more than 10 at%. and the intensity is saturated.

[Effects] Since the present invention is constituted by the above steps, it has the following excellent effects.

(B) It is possible to manufacture valves with complex shapes and has excellent strength, ductility, heat resistance, and oxidation resistance.

(b) Good yield and low manufacturing cost.

(C) Since there is less machining, mass production is possible and production time is shortened.

[Brief explanation of the drawing]

FIG. 1 shows a device used in the practice of the invention in its pre-operation state, and FIG. 2 its post-operation state. 1...Container 2...Dice 3...Press plate 4...Push bar Fig. 1 Fig. 2 1...Container 3...Press plate 2...Dice 4...Push bar

Claims (1)

[Claims] (1) A step of mixing Ti powder, Fe powder, or Ni powder, which is a raw material for aluminide, and Al powder or Al alloy powder in the following composition to form a mixture, and after solidifying this mixture hot or cold. A valve-shaped body or pseudo-valve consists of a process of cutting a billet to a predetermined length to create a billet for extrusion, extruding this billet, and an unextruded part that becomes the face of the valve, and an extruded part that becomes the stem of the valve. A method for manufacturing an aluminide intake and exhaust valve for an internal combustion engine, comprising the steps of forming a shaped body and reacting and sintering the valve shaped body or pseudo-valve shaped body. 25at%≦Ti or Fe or Ni≦75at%25a
t%≦Al or Al alloy≦75 at% (2) The component (at%) of the Al alloy contains one or more of the following elements, and the remainder is Al.
A method for manufacturing an aluminide intake and exhaust valve for an internal combustion engine according to claim 1. Cr...0.05-10 Mn...0.05-10 V...0.05-10 Co...0.05-10 Zr...0.05-10 Y...0.05-10 Mo...0.05-10 Nb ...0.05-10 Hf...0.05-10 Ta...0.01-10 W...0.01-10 Ce...0.01-10 Nd...0.01-10 Si...0.001-10 B... 0.01~5.0 C...0.001~5.0 N...0.001~5.0 O...0.01~1.0