JPS60106656A - Production of dispersion strengthened alloy casting - Google Patents

Abstract

PURPOSE:To improve the mechanical strength of a casting by dispersing uniformly fine particles for reinforcement into a metallic matrix by using a vertical pressure casting device provided with an electromagnetic stirrer. CONSTITUTION:Fine particles 13 for reinforcement and a molten metal 14 are poured into a sleeve 4 of a vertical pressure casting device which serves temporarily as a well the molten metal and an electromagnetic stirrer 10 is actuated. The molten metal 14 in the sleeve 4 is then stirred to suspend the particles 13 in the molten metal 14. The molten metal 14 is introduced into a gate 9 and product cavity 3 delineated by vertically split dies 1, 2 and thereafter the molten metal is pressurized by a plunger 6. The casting dispersed uniformly with the particles 13 is obtd. by the above-mentioned method by which the mechanical strength of the casting is improved.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a method for manufacturing dispersion-strengthened alloy castings, and in particular, strength etc. can be improved by dispersing reinforcing fine particles in a metal such as an aluminum alloy. Part II & relates to a method for manufacturing reinforced alloy castings.

[Prior art]

Dispersion-strengthened alloys in which hard, fine particles that are stable even at high temperatures are dispersed and composited in a metal matrix are known. For example, if the matrix is aluminum, S A
P (Sintered Aluminum Powd
er) is well known. Fine particles dispersed in this metal matrix prevent metal transfer and improve strength. Therefore, the greater the amount of fine particles present in the total bending matrix and the more uniformly they are dispersed, the higher the strength will be.

By the way, in order to manufacture such dispersion-strengthened alloy castings, a step of mixing molten metal and reinforcing fine particles is required.

Conventionally, the following two manufacturing methods have been used, depending on the timing at which reinforcing fine particles are mixed into the molten metal.

The first conventional method is to stir and mix /843i and reinforcing fine particles in a furnace (eg, vortex method), and then cast the mixture into a mold by gravity casting.

In this first conventional method, reinforcing fine particles made of ceramic or the like generally have poor wettability with the molten metal, so when stirring in the furnace is stopped, the reinforcing fine particles separate and become less likely to float. Furthermore, due to the time it takes to cast the metal from the furnace into the mold, and the long solidification time of the molten metal in gravity casting, the tendency for reinforcement fine particles to separate increases, thus ensuring uniform dispersion. The problem is that it can't be done. In addition, a stirring device inside the furnace is required,
There are problems in that it takes up space and increases cost.

As a countermeasure to this problem, it is possible to improve the wettability between the reinforcing fine particles and the molten metal, such as providing a coating layer on the surface of the reinforcing fine particles to increase the number of wettability, or adding a component to the molten metal that improves wettability. Although methods have been adopted, they are not always sufficient and are a factor in high costs.

The second conventional method is to mix reinforcing fine particles in the middle of the path of casting /8 hot water into the mold. This method includes /
There are methods such as a casting method in which a vortex is mixed in by creating a swirl flow in 8/Pi, and an injection dispersion method in which reinforcing fine particles are mixed into the molten metal flow at high speed.

However, in the second conventional method, reinforcing fine particles are mixed into the fluid flowing into the gold 7r, 2ζ.
There is a problem that there is a limit in quantity and the amount of dispersion is small. Additionally, solidification time is generally long due to gravity casting.
There is a problem that a uniform dispersion state cannot be obtained due to condensation of reinforcing fine particles.

[Purpose of the invention]

The present invention was made in order to solve the problems of the prior art described above, and provides a method for manufacturing Molecule i & reinforced alloy castings that can uniformly disperse reinforcing fine particles in metal 71.υnox. purpose.

C Structure of the Invention] According to the present invention, the present invention provides a mold that is divided into upper and lower parts defining a product cavity and a gate, and a sleeve that communicates with the gate and serves as a temporary pool for molten metal. , /8
Stir the plunger that pressurizes the hot water and the /8 field inside the sleeve.
A method for producing a dispersion-strengthened alloy casting using a vertical pressure casting device equipped with an electromagnetic stirring device, comprising: pouring reinforcing fine particles and molten metal into the sleeve; A method for producing a dispersion-strengthened alloy casting, characterized in that the reinforcing fine particles are stirred and suspended in the molten metal by actuation, the molten metal is introduced into the product cavity through a gate, and then the molten metal is pressurized with a plunger. achieved by.

Next, the configuration of the present invention will be explained with reference to the drawings.

In the present invention, a vertical pressure casting apparatus is used. In the present invention, the vertical pressure casting apparatus includes a vertical die casting apparatus and a high pressure casting apparatus. That is, the present invention is capable of retaining 1/8 hot water in the sleeve,
Any device that can pressurize can be used. Further, in the present invention, an electromagnetic stirring device is provided around the sleeve.

The reinforcing fine particles ζ used in the present invention must stably exist in the aluminum marlinox at high temperatures and must not grow or coarsen to cause a decrease in strength. Fine f1 gamma particles that meet this condition include oxides,
There are nitrides, carbides, metals, etc. Specifically, SiC,
, TiC, ZrC, WClNbC, , TiN, 13N,
Si, N4, 8I:O], hOlSiO2, Zr0i,
[N e, O), CuO1 graphite, W, C.

can be used.

The particle size of these fine particles is desirably 5 μm or less in order to achieve sufficient dispersion strengthening.

The method for forming dispersion-strengthened alloy castings of the present invention will be explained using the vertical pressure casting apparatus shown in the figure as an example.

FIG. 1 is a sectional view of a main part of a vertical pressure casting apparatus, where 1 is an upper mold and 2 is a lower mold. A product cavity 3 is defined by the upper mold I and the lower mold 2. A plunger sleeve 4 is provided in the center of the types I and 2, and a pressurizing plunger 5 and a counter plunger 6 are placed inside this plunger sleeve 4.
(The center is freely attached to the center 3 + ili. The tip 01'' and 1 of the branja 5.6 of this both swords are respectively equipped with the upper chino 7 and the counter tip 8. Also, the product cavity 3 and plunger sleeve 4 are
-9, 5% by weight of SiC fine particles 13 were charged to the molten metal 14. Then, the inside of sleeve 4 was heated to 720°C.

Pour molten aluminum alloy 14 (JIS AC4C),
By operating the electromagnetic stirring device 10, the alumina fine particles 13 were stirred and mixed into the melt #i14.

Next, while continuing the stirring, the counter chip 8 is lowered, the gate 9 is opened, and the aluminum alloy molten A14 is guided into the product cavity 3. At the same time, the pressure is applied by the pressurizing plunger 5, and the aluminum alloy/82814 is introduced into the product cavity 3. Fill it. The time from the completion of this pouring to the completion of filling into the product cavity 3 was about 3 seconds.

The high-temperature fatigue strength of the rocker arm obtained as a result at 150°C is approximately 25% higher than that of the first conventional method described above.
I bought it.

[Brief explanation of the drawing]

The figure is a sectional view of a vertical pressure casting apparatus used in the present invention. 1-----J type 2 2-----Lower mold 3-----Issei Toyabiti 4-----Plano jaw sleeve 5-----~Pressure plunger 6----Counter plunger 7 -------Pressure tip 8---Ichirikitsuntachisub9------Gate 10------1 Electromagnetic stirring device 11------Pouring port 12--1---Extrusion Pin 13 --- Reinforcement 11 "1 Particles 14 --- Molten metal applicant Toyotaro's amendment to the procedures for joining the company on leave of employment (Method) Mr. Commissioner of the Japan Patent Office 1, Indication of the case, 1988, 1-11 Patent Application No. 211594'T;-2,
Name of the invention, Part j1 (reinforced alloy 1) is the manufacturing method of the product 3, and the amendment is related to the cheater case Patent applicant address: 1 Toyota-cho, Yutaka 11, Aichi Prefecture February 28, 1982 Li 5, 471 Specification subject to amendment 6, contents of amendment

Claims (1)

[Claims] (1) A mold divided into upper and lower parts that defines a product cavity and a gate, a sleeve that communicates with the gate and serves as a temporary reservoir for molten metal, and a plunger that pressurizes the molten metal.
A method for producing a dispersion-strengthened alloy casting using a vertical pressure casting device equipped with an electromagnetic stirring device for stirring the molten metal in a sleeve, the method comprising: pouring reinforcing fine particles and the molten metal into the sleeve; The production of dispersion-strengthened alloy castings is characterized by stirring and suspending reinforcing fine particles in the molten metal by activating the molten metal, then introducing the molten metal into the product cavity through a gate, and then pressurizing the molten metal with a plunger. Method.