JPS6186064A - Production of composite metallic body compounded with inorganic fibers - Google Patents

Abstract

PURPOSE:To obtain a titled composite metallic body which has excellent strength and wear resistance and is free from variance in quality by dispersing small lumps formed by combining inorg. fibers with a metallic material consisting of Al, Mg, etc. into a separately prepd. metallic melt consisting of Al or Mg and subjecting the same to die casting. CONSTITUTION:The above-mentioned primary composite bodies made into small lumps by reworking are added under stirring to the separately prepd. metallic melt of Al or Mg and are dispersed and mixed therewith. Such mixture is ejected from a small hole and is poured fluidly into a cavity, by which the mixture is die-cast. The short fiber reinforcing material in the above-mentioned small lumps is thereby unraveled and uniformly dispersed, by which the intended composite metallic body compounded with the inorg. fibers is obtd. Carbon fibers, silicon carbide fibers, etc. are used as the reinforcing material to be used in this invention.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a metallic composite containing inorganic #tulle fibers, in which gold-iK inorganic fibers such as aluminum or magnesium are uniformly dispersed to provide excellent strength and durability. In addition to wear resistance, the aim is to obtain a product that is consistent in these properties.

Industrial applications A technology for manufacturing composites in which inorganic fibers are dispersed in metals such as aluminum or magnesium.

Conventional technology Materials in which inorganic short fiber reinforcing materials such as carbon, silicon carbide, or alumina are dispersed in a metal matrix such as aluminum or magnesium have excellent wear resistance and strength. Many studies are being conducted regarding its use in parts that require wear resistance and strength, such as industrial machinery and vehicles.

However, the reinforcing characteristics of a composite obtained by dispersing and blending such a reinforcing material greatly depend on the quality of the dispersion of the reinforcing material in the matrix, and therefore, various proposals have been made regarding methods for dispersing and compounding the reinforcing material. In other words, as a general method for manufacturing composites, a molded body made of pre-formed reinforcing material is
This is a method in which a molten metal called II Lux is forcibly infiltrated and solidified using a casting technique such as pressure casting or centrifugal casting to form a composite body. In some cases, the composite obtained by this general method is processed again into small lumps, and the small lumps are added to a separately prepared matrix melt in an appropriate ratio, stirred, dispersed and mixed, and then cast. There is a way to make it a composite.

Problems to be Solved by the Invention However, in the general method described above, the reinforcing material is molded in advance, and the IJ lux melt is forcibly infiltrated and solidified into the molded body to form a composite. However, there are many difficulties in manufacturing composites with thin walls and complex shapes. In addition, this composite is processed again into small pieces and made into another ma)
Even if the above-mentioned disadvantages can be alleviated by dispersing IJ lux in the melt, a uniform dispersion state cannot be obtained, and the reinforcing material is unevenly distributed, so that the abrasion resistance and strength are not sufficiently excellent. It doesn't become a thing.

``Structure of the Invention'' Means for Solving the Problems The present invention was devised to solve the problems of the conventional products as described above. Forming small lumps of primary phase coalescence made of composite fibers, dispersing the small lumps in a separately prepared aluminum or magnesium metal melt, and performing die casting by dynamic casting into a cavity Kffc. This is a method for producing a whole lipid complex containing inorganic 5fL fiber, characterized by:

The present invention can be effectively applied to the production of thin-walled or complex-shaped composites by casting small lumps of the primary collar assembly dispersed in a separately prepared aluminum or magnesium precious metal melt. By die-casting the b-bath water, it is possible to achieve favorable fluidization of the molten material at the sprue part and appropriately disperse the blended inorganic fibers, which eliminates the uneven distribution of the fibers and improves strength and its properties. Improve variation and significantly reduce wear amount? Come.

By setting the speed at the sprue to 35 m7'see or more, particularly 50 m/sec or more, each of the above effects can be achieved accurately.

EXAMPLE To further explain the present invention, the present inventors reprocessed the composite according to the general method described above into small lumps, added them to another molten matrix and stirred them to disperse and crystallize them. It has been found that the short fiber reinforcing material in the nodules is broken down and uniformly dispersed by die-casting by blowing out the holes.

As the reinforcing material used in the present invention, carbonaceous fibers, silicon carbide fibers, alumina fibers, and other inorganic short fibers can be widely used. As the matrix material in the primary coalescence to obtain the above-mentioned small lumps, 1000 series industrial ordinary purity aluminum, 4000 thread F)4%2+ aluminum alloy, etc. can be used as appropriate; 70
00 series heat-treated wrought alloys may also be used.

However, if an aluminum alloy for die-casting as shown in JI8H2212 or JI8H2118 or other die-castable aluminum alloy is used, the composition of the die-cast casting can be stabilized, which is advantageous.

In addition to magnesium ingots of ordinary purity such as class 1 or 2 not shown in JISH2150, magnesium alloys shown in JISH2221 can be used.
If a die-castable magnesium alloy such as the die-casting magnesium alloy ingot shown in SH2222 is used, it is advantageous because the composition can be stabilized after die-casting in the same manner as in the case of the above-mentioned aluminum metal.

The above-mentioned method for producing small lumps of primary collar coalescence involves infiltrating the inorganic short fiber aggregate with molten metal under pressure to impregnate the voids within the short fiber aggregate with aluminum or magnesium precious metals.This impregnation is carried out under high pressure. Even if a press or the like may be used, it is preferable to use a centrifugal casting device and impregnate under centrifugal pressure in order to sufficiently penetrate the bath water. The amount of molten metal to be impregnated into the short fiber aggregate is the amount necessary to sufficiently impregnate the inside of the aggregate, but excessive use of molten metal should be avoided since this simply increases the molten metal portion.

Short #1 impregnated with molten metal as above! After the fibers are cooled and solidified, they are crushed into small pieces, and any one of a crusher, a crusher, a beater, and an impeller breaker may be used for this crushing. It is also possible to cut it depending on the case.

The fiber content of the pellets obtained in this way is usually 10-
However, when impregnating the short fiber aggregate with molten aluminum, if the aggregate is compressed and impregnated under pressure, this fiber content should be reduced to 30 V.
o It can be increased to about 1%. In order to improve the dispersibility of the short fibers during die-casting, the crushed small lumps are preferably sieved as necessary to have a particle size of about 1 to 5 mm.

After cleaning the surface of the primary phase agglomerate obtained as described above with an acid or alkali solution if necessary,
The predetermined amount is mixed and melted with separately molten aluminum or aluminum alloy, flowed into a cavity, and die-cast. In addition to the general die-casting method, this die-casting method includes a method in which the inside of the mold cavity is in a vacuum or reduced pressure state, a die-casting method in which the waste inside the cavity is in a laminar flow state, and a die-casting method in which the inside of the cavity is replaced with oxygen. A plastic die casting method can be adopted. The sprue speed of the molten metal during this die casting is determined by the sprue opening, the mold cavity volume, and the filling time, or by setting the sprue speed to 35 m/sec or more,
The short fibers in the primary phase coalescence can be uniformly dispersed in the die-cast plate composite, preferably 50 m
/sec, but the speed is further increased to 200m/sec
Even if it is more than c, the symmetry state will not be satisfied, resulting in an increase in the size of the equipment and a meaningless loss of energy.

A specific example of the lining according to the present invention using aluminum material is as follows.

Alumina vessel K 1 r with a diameter of 70 mm and a depth of 150 mm.
Filled with alumina short fibers with a length of less than 100 mm to a depth of 50 mm, and on top of the alumina fibers, 3% Cu-9.5% 5L-1
%Mj-1%N1 alloy molten metal was injected and placed in a centrifugal casting machine, and the centrifugal casting machine was operated at a rotation radius of 250 m + n1 rotation speed of 150 Orpm to apply a far Ib force to impregnate the short fiber aggregate with the molten metal. Ta. This material was taken out in a semi-molten state, crushed with a hammer, and the crushed composite was separated with a sieve to prepare small pieces of 1 to 5 m.

The above gu 0 is ii:'? The primary phase coalesced lumps were separately prepared by melting Al-3%Cu-1% homogeneous 1%Ni-0.
．． Added to 6% Fs alloy molten metal 100H while stirring,
Various mixed hot water baths were prepared in which short fibers were mixed with 1% MaO and 0 to 10% MaO, and the mixed hot water baths were die-cast by varying the sprue speed.

In addition, for comparison, a similar composite was manufactured by using the mixed molten metal prepared as described above.

For each of the composites obtained as described above, the strength using a universal tensile sample and the abrasion resistance were measured according to the five measurement conditions shown in Table 1 below.

In other words, if such measurement results are organized and summarized according to the content of alumina short fibers and shown together with comparative examples, the results are as shown in Table 2 below.
The numerical value in i/d, c) is the variation range (maximum value - minimum value), and the numerical value without any parentheses is the wear amount (■
).

Table 3 below summarizes the case where the group content of the alumina short fibers was 5% and the sprue speed of the molten metal was varied under certain conditions.

That is, when the sprue speed is 35 m/sec or more, the variation is drastically reduced and the strength is increased, and the amount of wear is significantly reduced by about one order of magnitude compared to the comparative example. It is estimated that there is no essential change in these measured values when the sprue speed is 50 m/sec or higher. Regarding strength variation, 2 to 4 #/- under conditions where the strength itself is greatly increased.
It is extremely significant that this is the case.

Although the above description is for the case where aluminum metal is used, it has been confirmed that the present invention has the same effect even when magnesium metal is used.

"Effects of the Invention" According to the present invention as explained above, the quality of this type of composite is greatly improved, and the strength is appropriately improved and the range of variation thereof is appropriately reduced. This invention is industrially very effective.

Claims (1)

[Claims] 1. Form a small lump of a primary composite consisting of a metal such as aluminum or magnesium mixed with inorganic fiber, and use the small lump as a separately prepared aluminum or magnesium metal. A method for producing a metallic composite containing inorganic fibers, which comprises dispersing a molten material into a cavity and performing die casting. 2. The speed of the molten material at the sprue of die casting is 3.
A method for manufacturing a metallic composite compounded with the inorganic fiber according to claim 1, wherein the velocity is 5 m/sec or more.