JPH0428832A - Manufacture of suction and exhaust valve for internal combustion engine made of aluminide - 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] [Industrial Application Fields] This invention is made of aluminide for internal combustion engine intake and exhaust. The present invention relates to a method for manufacturing a valve.

[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 low-cost for use in aluminide internal combustion engines.
The purpose of the present invention is to provide a method for manufacturing an exhaust valve.

[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 process of solidifying this mixture hot or cold, extruding it and cutting it into a predetermined length, a process of upsetting and forging this extruded material of a predetermined length into a bulb shape, and reacting and sintering this upsetting forged member. 25at%≦Ti or Fe or Ni≦75at%25a
t%≦Al or Al alloy≦75at% [Function] 25at%≦Ti or Fe or Ni≦75at%25a
A mixture with a composition of t%≦Al or Al alloy≦75 at% is solidified in hot or cold, extruded and cut into a predetermined length, and this predetermined length of extruded material is installed in a bulb shape. By performing reactive sintering after forging, aluminide intake and exhaust valves for internal combustion engines can be obtained.

[Example] Examples of the present invention will be described below along with drawings of an apparatus used to carry out the invention. Inner diameter 30 as shown in Figure 1.2
A valve mold 2 is integrally fixed within a #l thick-walled cylindrical forging mold 1. The valve type 2 has a recess 2a corresponding to the face portions of intake and exhaust valves of an internal combustion engine, and a long hole 2b having a diameter of 10 mm corresponding to the stem portion.

Example 1 T with the following composition of Ti powder, Fe powder, or Ni powder and Al powder or Al alloy powder, which are raw materials for aluminide.
i-47Al-3Mn Example 2 Ti-48AL
-2V Example 3 Fe-40Al-13+ Example 4 Ni-26Al, a short cylindrical mixture extruded material 3 having dimensions of φ30ai The material is placed in a forging die 1 as shown in FIG. 2, and is forged by a ram 4 at a stroke of 15 Jll11 and a pressure of 250 tons, as shown in FIG. 2, to obtain an upsetting material 5 having a valve shape or a pseudo-valve shape. This upsetting material 5 was taken out of the forging die 1 and subjected to the heat treatment shown in Table 1 (pre-diffusion treatment in vacuum, reaction sintering by HIP in 1200 atm Ar gas,
The material was homogenized (in vacuum) to form aluminide, which was then processed into the desired valve shape. Table 1 shows the heat treatment conditions for 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 Ce...0.05~10 zr-o, 05~10 Y...0.0505 - 1O...0.05~1O Nb...0.05~10 Hf...0.05~10 Ta-0,05~10 W...0.01~10 Ce-0,01~ 1O Nd...0.01-10 Sl...○, O○1-10 B...0.01-5.0 C...0.001-5. O N...O0O○1~5.0 ○...0.01~1.0 When producing aluminide, the following points should be noted regarding each of the above components: (a) Al, T+ Fe, N+ If it is less than 25 at% or more than 75 at%, the alloy will not react and it will be difficult to form an intermetallic compound.

(b) Regarding Cr, Mn, B, C, and N, Cr, Mn,
is less than 0.05 at%, B is less than 0°01 at%, C,
If N 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. Q
Above at%, the improvement in ductility is saturated.

(C> Regarding W and Sl, no improvement in oxidation resistance is observed when W is less than 0.O'lat% and 3i is less than 0.001 at%, and when W and S exceed 10 at%, oxidation resistance is saturated. .

(d) Co, Zr, Y, Mo, Nb, Hf, Ta, Ce
, Co, Zr, Y, MO, Nb, HfGto, 05at% for Nd
(For Ta, Ce, Nd, O, C) If the content of each element is less than 10 at%, no improvement in strength is observed, and if each element exceeds 10 at%, the strength is saturated.

Since this invention is constituted by the above steps, it has the following excellent effects.

(a) 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 less machining is required, mass production is possible and manufacturing time is shortened.

[Brief explanation of drawings]

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... Forging die 2... Valve die 3... Extruded material 4... Ram 5... Upsetting material

Claims (1)

[Claims] (1) A process 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 solidifying this mixture hot or cold and extruding it. a step of cutting the extruded material to a predetermined length; a step of upsetting and forging the extruded material of the predetermined length into a valve shape;
A method of manufacturing an aluminide intake and exhaust valve for an internal combustion engine, which comprises a step of reaction-sintering this upsetting forged member. 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...0.05-10 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