Toyota Jidosha Kabushiki Kaisha

Isolite Babcock Refractories Co., Ltd.

Tadashi Dohnomoto

Atsuo Tanaka

Masahiro Kubo

Kaneo Hamajima

Hidetoshi Hirai

Yoshiaki Kajikawa

Yoshio Fuwa

Yorishige Maeda

Yoshiaki Tatematsu

Hirohumi Michioka

Yoshitaka Takahashi

Shiro Machida

Haruo Kito

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 a method for making a carbon fiber reinforced material, a mass of carbon fibers, disposed in a closed loop configuration, and initially having a Young's modulus which is between about 23 ton/mm.sup.2 (23,000 kg/mm.sup.2) and about 35 ton/mm.sup.2 (35,000 kg/mm.sup.2), is embedded within a mass of matrix metal by a process which involves the mass of matrix metal being heated at least to its melting point. A composite material made by such a method is also disclosed. Preferably, the carbon fibers, before being thus embedded in the mass of matrix metal, should have a Young's modulus which is between about 23 ton/mm.sup.2 and about 30 ton/mm.sup.2. By the Young's modulus of the carbon fibers thus being relatively moderate, the occurrence of faults such as cracks and fissures in the resulting composite material is obviated, and the resulting composite material has good strength and other characteristics.

Composite material including matrix metal and closed loop configuration

A composite material is made from reinforcing fiber material embedded in a matrix of metal. The matrix metal is a light metal such as aluminum alloy or magnesium alloy. The reinforcing fiber material is a mixture of potassium titanate whiskers and a short fiber material, which is one or a mixture of: silicon carbide whiskers, silicon nitride whiskers, alumina short fibers, crystalline alumina-silica short fibers, and amorphous alumina-silica short fibers. The overall volume proportion of the reinforcing fiber material in the composite material is between approximately 5% and approximately 50%, and more desirably may be between approximately 5% and approximately 40%, and even more desirably may be between approximately 10% and approximately 40%. And the relative volume proportion of the potassium titanate whiskers in the reinforcing fiber material is from about 10% to about 80%, and more desirably may be between approximately 10% and approximately 70%, and even more desirably may be between approximately 20% and approximately 60%.

Composite material with light matrix metal and with reinforcing fiber

A composite material is made from alumina-silica type short fibers embedded in a matrix of metal. The matrix metal is an alloy consisting essentially of from approximately 2% to approximately 6% of copper, from approximately 0.5% to approximately 3.5% of magnesium, and remainder substantially aluminum. The short fibers have a composition of from about 35% to about 80% of Al.sub.2 O.sub.3 and from about 65% to about 20% of SiO.sub.2 with less than about 10% of other included constituents, and may be either amorphous or crystalline, in the latter case optionally containing a proportion of the mullite crystalline form. The fiber volume proportion of the alumina-silica type short fibers is between approximately 5% and approximately 50%, and may more desirably be between approximately 5% and approximately 40%. If the alumina-silica short fibers are formed from amorphous alumina-silica material, the magnesium content of the aluminum alloy matrix metal may desirably be between approximately 0.5% and approximately 3%. And, in the desirable case that the fiber volume proportion of the alumina-silica type short fibers is between approximately 30% and approximately 40%, then the copper content of the aluminum alloy matrix metal is desired to be between approximately 2% and approximately 5.5%.

Composite material including alumina-silica short fiber reinforcing

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 composite material is made from silicon carbide and/or silicon nitride short fibers embedded in a matrix of metal. The metal is an alloy consisting essentially of between approximately 2% to approximately 6% of copper, between approximately 0.5% to approximately 3% of silicon, and remainder substantially aluminum. The short fibers may be all silicon carbide short fibers, or may be all silicon nitride short fibers, or may be a mixture of silicon carbide and silicon nitride short fibers. The fiber volume proportion of the silicon carbide and/or silicon nitride short fibers may desirably be between approximately 5% and approximately 50%, and may more desirably be between approximately 5% and approximately 40%.

Composite material including silicon carbide and/or silicon nitride

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.

Production of pistons having a cavity

The fiber reinforced metal composite material according to this invention provides a composite material comprising, in combination, alumina-fibers or alumina-silica fibers excellent in abrasion resistance, heat resistance and seizure resistance and hypereutectic aluminum-silicon-type alloys enriched with proeutectic silicon which is hard grains.

Fiber reinforced metal composite material

A light metal alloy cast piston including a thermal strut (32, 48, 52) arranged in a shoulder portion of the piston skirt. The thermal strut is composed of an annular fiber-reinforced metal portion in which high-tensile-strength reinforcing fibers are integrally molded. The reinforcing fibers include first fibers (34), such as carbon fibers, having a coefficient of linear expansion substantially smaller than that of the matrix metal alloy, and second fibers (36), such as silicon carbide fibers and alumina fibers, having a flexural or bending strength larger than that of the first fibers. The first fibers primarily serve to restrain thermal expansion of the piston skirt and the second fibers, having a larger bending strength, act to protect the first fibers from excessive bending forces. In a preferred embodiment, the first fibers are located in the inner region of the thermal strut and the second fibers are arranged in the outer region.

Light metal alloy piston

This composite material includes reinforcing hybrid fiber mixture material in a matrix of metal which is aluminum, magnesium, copper, zinc, lead, tin, or an alloy having these as principal components. The hybrid fiber mixture is a mixture of crystalline alumina-silica fiber material and mineral fiber material. The crystalline alumina-silica fiber material has as principal components 35% to 80% by weight of Al.sub.2 O.sub.3 and 65% to 20% by weight of SiO.sub.2, with a content of other substances of less than or equal to 10% by weight, and with the percentage of mullite being greater than or equal to 15% by weight, and with the percentage of non fibrous particles with diameters greater than 150 microns being less than or equal to 5% by weight. And the mineral fiber material has as principal components SiO.sub.2, CaO, and Al.sub.2 O.sub.3, the content of MgO being less than or equal to 10% by weight, the content of Fe.sub.2 O.sub.3 being less than or equal to 5% by weight, and the content of other inorganic substances being less than or equal to 10% by weight, with the percentage of non fibrous particles being less than or equal to 20% by weight, and with the percentage of non fibrous particles with diameters greater than 150 microns being less than or equal to 7% by weight. The volume proportion of the reinforcing hybrid fiber material is at least 1%. The qualities of this composite material with regard to wear, wear on a mating member, and bending strength are good.

Composite material made from matrix metal reinforced with mixed

This composite material is composed essentially of a matrix metal which is copper or an alloy thereof, and a reinforcing fiber material which is a collection of alumina - silica type short fibers in which the included amount of alumina is about 40% by weight or more, with the total amount of non fibrous particles included in the collection of fibers being less than or equal to about 7% by weight, with the total amount of non fibrous particles with diameter greater than or equal to about 150 microns included in the collection of fibers being less than or equal to about 1% by weight, and with the volume proportion of the short fiber material being from about 0.5% to about 30%. Optionally and preferably, this volume proportion of short fiber material is from about 1.0% to about 25%, or from about 0.5% to about 10%, or even better from about 1.0% to about 5%. And the total amount of non fibrous particles can be less than or equal to about 4% by weight; and the total amount of non fibrous particles with diameter greater than or equal to about 150 microns can be less than or equal to about 0.6% by weight. The reinforcing fiber material can be fibers containing a substantial amount of silica, or alternatively can be a fiber material substantially made only of alumina; and may contain a substantial amount of, or consist substantially only of, alpha alumina. The matrix material may be pure copper, brass, or bronze.

Fiber reinforced material with matrix metal containing copper and

A composite material, including reinforcing fiber material with principal components SiO.sub.2 and/or CaO and/or Al.sub.2 O.sub.3, and with a Mg content by weight of between about 0% and about 10%, an Fe.sub.2 O.sub.3 content by weight of between about 0% and about 5%, and a content by weight of other inorganic substances of between about 0% and about 10%, and consisting essentially of mineral fibers and non fibrous particles to a total percentage of not more than about 20% by weight, the weight percentage of the part of the non fibrous particles which have a diameter of greater than or equal to about 150 microns being between about 0% and about 7%. Also, the composite material includes a matrix metal selected from the group consisting of aluminum, magnesium, copper, zinc, lead, tin, and alloys having these as principal components, the volume proportion of the mineral fibers being in the range of from about 4% to about 25%. This composite material is economical to manufacture and has very good wear characteristics, machinability, and bending strength.

Composite material including reinforcing mineral fibers embedded in

This composite material includes reinforcing hybrid fiber mixture material in a matrix of metal which is aluminum, magnesium, copper, zinc, lead, tin, or an alloy having these as principal components. The hybrid fiber mixture is a mixture of amorphous alumina-silica fiber material and mineral fiber material. The amorphous alumina-silica fiber material has as principal components 35% to 80% by weight of Al.sub.2 O.sub.3 and 65% to 20% by weight of SiO.sub.2, with a content of other substances of less than or equal to 10% by weight, with the percentage of non fibrous particles included therein being less than or equal to about 17% by weight, and with the percentage of non fibrous particles with diameters greater than 150 microns being less than or equal to 7% by weight. And the mineral fiber material has as principal components SiO.sub.2, CaO, and Al.sub.2 O.sub.3, the content of MgO being less than or equal to 10% by weight, the content of Fe.sub.2 O.sub.3 being less than or equal to 5% by weight, and the content of other inorganic substances being less than or equal to 10% by weight, with the percentage of non fibrous particles being less than or equal to 20% by weight, and with the percentage of non fibrous particles with diameters greater than 150 microns being less than or equal to 7% by weight. The volume proportion of the reinforcing hybrid fiber material is at least 1%. The qualities of this composite material with regard to wear and bending strength are good.

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Toyota, Japan

Tadashi Dohnomoto