Aluminum alloy composite material with intermetallic compound finely dispersed in matrix among reinforcing elements
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsKaneo Hamajima, Atsuo Tanaka, Tadashi Dohnomoto, Yoshio Fuwa, Hirohumi Michioka
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Abstract
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.
Claims31
An aluminum alloy material including a local portion reinforced to form a composite material comprising a matrix of an aluminum alloy, a reinforcing material of short fibers, whiskers or particles, and intermetallic compounds made of Al and at least one metallic element selected from the group consisting of Fe, Ni, Co, Cr, Cu, Mn, Mo, V, W, Ta, Nb, Ti and Zr as finely dispersed in the matrix at 5-70% by volume, said aluminum alloy material having been manufactured by forming a porous body of a mixture of said reinforcing material and a powder of said selected metallic element or elements, placing said porous body in a molding cavity of a casting mold, charging a molten body of said aluminum alloy into said molding cavity, and infiltrating a pan of said molten body of said aluminum alloy into said porous body.
An aluminum alloy casting comprising a local composite material portion which defines a surface portion of said aluminum alloy casting, said composite material portion comprising a matrix of an aluminum alloy, a reinforcing material of short fibers or whiskers, and intermetallic compounds made of Al and at least one metallic element selected from the group consisting of Fe, Ni, Co, Cr, Mn, Mo, V, W, Ta, Nb, Ti and Zr as finely dispersed in the matrix, wherein as viewed in a surface portion of the casting the ratio by area of such intermetallic compounds having a ratio of L/D greater than 3 is less than 30%, where L and D are length and width of each intermetallic compound element, respectively, said aluminum alloy casting having been manufactured by forming a porous body of a mixture of said reinforcing material and a powder of said selected metallic element or elements, placing said porous body adjacent a wall of a molding cavity of a casting mold, charging a molten body of said aluminum alloy into said molding cavity, and infiltrating a part of said molten body of said aluminum alloy charged in said molding cavity into said porous body.
A piston for an internal combustion engine of an aluminum alloy, wherein at least a lower surface of a top ring groove is defined by a composite material comprising a matrix of said aluminum alloy, a reinforcing material of short fibers, whiskers of particles, and intermetallic compounds made of Al and at least one element selected from the group consisting of Fe, Ni, Co, Cr, Cu, Mn, Mo, V, W, Ta, Nb, Ti and Zr, the amount of said reinforcing material in said composite materials being more than 3% by volume, the amount of said intermetallic compounds being 10-15% BY volume, and the total amount of said reinforcing material and said intermetallic compounds being less than 60% by volume, said piston having been manufactured by forming an annular porous body of a mixture of said reinforcing material and powder of said selected metallic element or elements, placing said annular porous body along an annular corner of a cylindrical molding cavity of a casting mold, charging a molten body of said aluminum alloy into said molding cavity, infiltrating a part of said molten body of said aluminum alloy charged into said molding cavity into said porous body, and cutting said top ring groove in a portion of a cast body incorporating said porous body therein.
Dependencies are inferred from the claim text.