Toyota Jidosha Kabushiki Kaisha

Kaneo Hamajima

Atsuo Tanaka

Tadashi Dohnomoto

Masahiro Kubo

Shinji Kato

Yoshio Fuwa

Tetsuya Suganuma

Hirohumi Michioka

Yoshiaki Kajikawa

A slide member is made of an aluminum alloy and compositely reinforced at its sliding surface by a reinforcing material. The reinforcing material is a mixture of alumina short fibers consisting of not less than 80 wt. % alumina and the remainder silica and having 5-60 wt. % alpha alumina content, and non-spherical mullite particles consisting of 40-86 wt. % alumina and the remainder silica and having 3-60 microns mean diameter. The volumetric percentages of the alumina short fibers and the mullite particles are 2-12% and 5-25%, respectively, on the basis of the volume of the reinforced portion.

Slide member made of an aluminum alloy

Disclosed is a polymer powder cross-linked by metallic ions and containing reinforcing material which includes a polymer cross-linked by metallic ions, and at least one reinforcing material selected from the group consisting of a fibrous reinforcing material and a particulate reinforcing material and contained uniformly in the polymer cross-linked by metallic ions in an amount of from 3 to 70% by volume. The polymer powder can be processed into a composite material based on the polymer. The composite material is improved in the strength and the impact resistance while maintaining the superb physical properties of the polymer, because the reinforcing material is dispersed too uniformly to be localized therein. Additionally, processes are disclosed which are suitably adapted to produce the polymer powder and the composite material.

Polymer powder cross-linked by metallic ions and containing reinforcing

In an aluminum alloy composite material including an aluminum alloy matrix and a reinforcing material such as fibers, whisker or particles, intermetallic compounds made of Al and at least one selected from a group of Fe, Ni, Co, Cr, Cu, Mn, Mo, V, W, Ta, Nb, Ti and Zr are finely dispersed in the matrix existing among reinforcing material elements so as to maintain rigidity of the matrix alloy necessary to support the reinforcing material elements at high temperature. Optimum shapes and volumetric density of such intermetallic compounds are experimentally obtained.

Aluminum alloy composite material with intermetallic compound finely

A preform for being embedded in a matrix material for making a composite material is made essentially of many short fibers stuck together by a quantity of dried binder. This preform has a first portion in which the fiber volume proportion is relatively high, a second portion in which the fiber volume proportion is relatively low, and a third portion, joining between the first portion and the second portion, in which the fiber volume proportion changes substantially continuously from its portion adjoining to the first portion to its portion adjoining to the second portion. Thereby, the characteristics of the composite material, such as its strength, heat and wear resistance, and machinability and workability and characteristics with respect to wear on a mating member, alter smoothly from the first portion to the second portion without any severe discontinuity, thus ensuring that no points of weakness are caused. A method for making such a preform, and a composit material object manufactured using such a preform, which may be an engine piston, are also disclosed.

Short fiber preform, method of making it, and composite material

In this method for making an alloy of a first metal and a second metal which has a stronger tendency to form an oxide than the first metal, a powdered solid is prepared comprising at least one of a compound of the first metal with oxygen and the second metal, the compound is mixed with the second metal, and an alloying process is carried out of alloying a melt with the powdered solid, in which the second metal is oxidized by the oxygen of the compound of the first metal with oxygen which is reduced. The compound of the first metal with oxygen may be an oxide, and may be a simple oxide or a compound oxide. As one variation, the powdered solid may contain the compound of the first metal with oxygen, in which case the melt will contain the second metal; or alternatively the powdered solid may contain the second metal, in which case the melt will contain the compound of the first metal with oxygen. Alternatively, the powdered solid may contain both the compound of the first metal with oxygen and the second metal, in which case the melt may contain a third metal.

Process for manufacturing alloy including fine oxide particles

In this method for manufacturing an aluminum alloy, a porous preform is manufactured from a mixture of a finely divided oxide of a metallic element which has a weaker tendency to form oxide than does aluminum, and an additional substance substantially more finely divided than that metallic oxide. Then an aluminum alloy containing a substantial quantity of silicon is permeated in the molten state through the porous preform. This causes the metallic oxide to be reduced by a thermite reaction, to leave the metal which it included as alloyed with the aluminum alloy. At this time, the silicon in the aluminum alloy does not tend to crystallize out upon the particles of the metallic oxide, which would interfere with such a reduction reaction by forming crystalline silicon shells around such metallic oxide particles and would lead to a poor final product, because instead the silicon tends to crystallize out upon the particles of the additional substance. This alloying method is effective even if the average particle diameter of the finely divided metallic oxide, on the assumption that it is in the form of globular particles, is less than about 10 microns. The melting point of the additional substance should desirably be substantially higher than the melting point of the aluminum alloy. The silicon content of the aluminum alloy may freely be greater than about 1.65% by weight. Desirably, the preform may further contain reinforcing fibrous material. And, particularly, the additional substance may be Al.sub.2 O.sub.3.

Method for manufacturing aluminum alloy by permeating molten aluminum

A piston of a light alloy matrix material having a cavity for containing heat insulating air immediately below its head or a cavity for passing cooling oil inside the grooved side wall is manufactured by preforming a precursory member having the shape of the cavity from an extractable material which remains in solid state at room temperature and is convertible into a fluid, gas or liquid when heated at a temperature below the melting point of the matrix metal. The precursory member is disposed in place in a pressure casting mold having a cavity corresponding to the shape of the piston, and covered with a porous member stable to the molten matrix metal. A head member of heat resisting metal material to constitute at least a portion of the piston head may be disposed on the mold cavity bottom. Molten matrix metal is then cast into the mold cavity and a pressure is applied thereto to form a piston-shaped casting having precursory member and porous member embedded therein. Finally the casting is heated at a sufficient temperature to gasify or liquefy the extractable material of the precursory member material into fluid, which is extracted from the casting, leaving a cavity at the location of the precursory member. Alternatively, the precursory member may be formed from a composite material of a gasifiable material and a stable material whereby the cavity is given as a porous insert of the stable material which is left after the extraction of the gasifiable material by heating.

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Toyota, Japan

Kaneo Hamajima