Abstract: A magnesium alloy member includes a member main body formed of a magnesium alloy containing aluminum, and an anodic oxidation coating covering at least a portion of the member main body. The anodic oxidation coating includes a porous first layer and a second layer located between the first layer and the member main body and having a higher aluminum content than that of the first layer. The ratio of the thickness of the second layer with respect to the thickness of the anodic oxidation preferably is about 5% to about 20%.

Abstract: An engine component is composed of an aluminum alloy containing silicon, and includes a plurality of primary-crystal silicon grains located on a slide surface. The plurality of primary-crystal silicon grains have an average crystal grain size of no less than about 12 ?m and no more than about 50 ?m.

Abstract: An engine component is composed of an aluminum alloy containing silicon, and includes a plurality of primary-crystal silicon grains located on a slide surface. The plurality of primary-crystal silicon grains have an average crystal grain size of no less than about 12 ?m and no more than about 50 ?m.

Abstract: A magnesium alloy member includes a member main body formed of a magnesium alloy containing aluminum, and an anodic oxidation coating covering at least a portion of the member main body. The anodic oxidation coating includes a porous first layer and a second layer located between the first layer and the member main body and having a higher aluminum content than that of the first layer. The ratio of the thickness of the second layer with respect to the thickness of the anodic oxidation preferably is about 5% to about 20%.

Abstract: An engine component is composed of an aluminum alloy containing silicon, and includes a plurality of primary-crystal silicon grains located on a slide surface. The plurality of primary-crystal silicon grains have an average crystal grain size of no less than about 12 ?m and no more than about 50 ?m.

Abstract: An engine component is composed of an aluminum alloy containing silicon, and includes a plurality of primary-crystal silicon grains located on a slide surface. The plurality of primary-crystal silicon grains have an average crystal grain size of no less than about 12 ?m and no more than about 50 ?m.

Abstract: An internal combustion engine includes a cylinder block formed of a metal material, a cylinder liner formed of a metal material different from that of the cylinder block, the cylinder liner being fitted onto the cylinder block, a water jacket provided between the cylinder block and the cylinder liner for retaining a coolant, and a sealing member provided in contact with the cylinder block and the cylinder liner, the sealing member preventing leakage of the coolant from the water jacket. The cylinder block and the cylinder liner have respective positioning surfaces, each of which determines a relative position against the other. The positioning surfaces are provided on the opposite side of the sealing member from the water jacket. The cylinder block and the cylinder liner are spaced apart from each other, in between the sealing member and the water jacket.

Abstract: An engine component is composed of an aluminum alloy containing silicon, and includes a plurality of primary-crystal silicon grains located on a slide surface. The plurality of primary-crystal silicon grains have an average crystal grain size of no less than about 12 ?m and no more than about 50 ?m.

Abstract: A composite piston and method for forming such a piston for a reciprocating machine such as an internal combustion engine. A blank is formed from a pair of dissimilar alloys, one of which has substantially greater properties such as strength or abrasion resistance. The blank is formed by a process whereby he two materials are initially bonded and extruded into a composite blank. The blank is forged into a piston in such a way that the two materials are bonded together in the forging process. The higher strength and/or abrasion resistance material forms at least a part of the outer surface of the piston in areas where the better properties are required. The other material backs up the higher strength or hardness material in necessary areas so as to provide an integral structure that has lightweight, low costs and nevertheless the desired properties.

Abstract: A composite piston and method for forming such a piston for a reciprocating machine such as an internal combustion engine. A blank is formed from a pair of dissimilar alloys, one of which has substantially greater properties such as strength or abrasion resistance. The blank is forged into a piston in such a way that the two materials are bonded together in the forging process. The higher strength and/or abrasion resistance material forms at least a part of the outer surface of the piston in areas where the better properties are required. The other material backs up the higher strength or hardness material in necessary areas so as to provide an integral structure that has lightweight, low costs and nevertheless the desired properties. Various physical constructions and forming operations are disclosed.

Abstract: The present invention is a piston for use in an internal combustion engine and a method of manufacturing the piston. In the method of the present invention, a first block comprising a first alloy and a second block comprising a second alloy are press-forged to form a piston. The piston has a head and a skirt, with the head comprising at least a portion of the first alloy and the skirt comprising at least a portion of the second alloy. The first alloy preferably comprises an aluminum-iron based alloy, and the second alloy preferably comprises an aluminum-silicon based alloy. Preferably, during the forging process an interface between the blocks is increased in length or area, whereby oxide layers on the blocks are destroyed and the material comprising the two alloys is bonded directly.

Abstract: An improved method of forging a piston and a forging die therefor. The forging die is formed from a pair of pieces which form an area where the forged material is extruded into. These pieces merge at a parting line that passes through the center of the outer edge of the forged material so as to afford some relative movement between the die pieces to avoid cracking and also to permit air to escape. Some small flash or parting line may be present in the finished material which is not objectionable and permits the attainment of the higher strength and better wear resistant piston.

Abstract: A method of forming a piston for a reciprocating machine such as an engine. The piston is formed from a powdered material that is comprised of aluminum alloyed with a material selected from the group of silicon (Si) and iron (Fe) having a particle diameter not greater than 10 .mu.m. The resulting alloy is then forged into a piston having a piston head and a piston skirt. The powder which is solidified and forged is formed by a process comprising the steps of forming an ingot from an alloy comprised of aluminum and an alloying material. This ingot is then melted and dispersed as a liquid in a chilling stream to form powdered metal particles. These powdered metal particles are then compressed into a blank having a cylindrical configuration for subsequent forging.

Abstract: A composite piston and method for forming such a piston for a reciprocating machine such as an internal combustion engine. A blank is formed from a pair of dissimilar alloys, one of which has substantially greater properties such as strength or abrasion resistance. The blank is forged into a piston in such a way that the two materials are bonded together in the forging process. The higher strength and/or abrasion resistance material forms at least a part of the outer surface of the piston in areas where the better properties are required. The other material backs up the higher strength or hardness material in necessary areas so as to provide an integral structure that has lightweight, low costs and nevertheless the desired properties. Various physical constructions and forming operations are disclosed.

Abstract: In a method of manufacturing the piston, a first block including first alloy and a second block including a second alloy are press-forged to form a piston. The piston has a head and a skirt, with the head including at least a portion of the first alloy and the skirt including at least a portion of the second alloy. The first alloy preferably including an aluminum-iron based alloy, and the second alloy preferably comprises an aluminum-silicon based alloy. Preferably, during the forging process an interface between the blocks is increased in length or area, whereby oxide layers on the blocks are destroyed and the material comprising the two alloys is bonded directly.

Abstract: An aluminum alloy for pistons and a method of manufacturing pistons making use of said alloy, enabling casting without sacrificing the ease of casting, and restricting deformation and melting at high temperatures, and fatigue and wear caused by high speed sliding movement. The aluminum alloy contains Si+SiC in an amount in the range of 8% to 20% by weight, and SiC in an amount of 2% or more by weight. An ingot containing the aluminum alloy is melted, sprayed in the state of mist, rapidly cooled and solidified into rapidly cooled powder. The rapidly cooled powder is heated and solidified into a blank from which the piston is forged, heat-treated, and machined.