Abstract: A forming method wherein a billet (31, 66, 77, 87, 107, 128, 136, 144, 153, 77B, 77C) comprising a metal-based composite material (27) prepared by mixing an aluminum alloy (22) and a ceramic (15) is subjected to pressure forming to manufacture a formed article, which comprises carrying out the pressure forming by the use of different compression ratios for different portions of the formed article, wherein a compression ratio means the ratio of the height of a billet before the pressure forming to height of the billet after the pressure forming. The above forming method allows the manufacture of a formed article having different volume contents 8Vf) of the ceramic for different portions thereof.

Abstract: An aluminum base composite material (10) having an aluminum alloy (11) as a base material and, incorporated therein, a reinforcing material (12) composed of alumina particles of alumina fibers, wherein a spinel layer (13) is formed on the surface of the reinforcing material and an aluminum nitride layer (14) exhibiting excellent wettability is formed on the surface of said spinel layer.

Abstract: A brake drum includes a ring-shaped drum body, and a friction member secured to the inner circumferential surface of the drum body. Because the drum body is formed of a lightweight Al alloy and the friction member is formed of an Al-base composite material, the brake drum can be reduced in weight as a whole. Further, because the friction member, having projection portions formed on its outer periphery, is cast enveloped by molten metal of the Al alloy, the friction member and the drum body can be firmly fastened together. Thus, even when a great braking force is applied to the drum brake, the friction member can be prevented from being undesirably detached from the drum body.

Abstract: A brake drum has its strength elevated in its disk portion. The brake drum is formed from a composition having ceramics dispersed in a matrix. The disk portion has a high ceramic content and thereby a high strength. Its cylindrical portion has a ceramic content decreasing gradually from the outer edge of the disk portion.

Abstract: A brake drum has its strength elevated in its disk portion. The brake drum is formed from a composition having ceramics dispersed in a matrix. The disk portion has a high ceramic content and thereby a high strength. The brake drum has a disk portion and a cylindrical portion. The disk portion has a first ceramic content by volume and the cylindrical portion has a second ceramic content by volume that is less than the first ceramic content by volume as a result of the application of a higher compression ratio to the disk portion.

Abstract: A forming method wherein a billet (31, 66, 77, 87, 107, 128, 136, 144, 153, 77B, 77C) comprising a metal-based composite material (27) prepared by mixing an aluminum alloy (22) and a ceramic (15) is subjected to pressure forming to manufacture a formed article, which comprises carrying out the pressure forming by the use of different compression ratios for different portions of the formed article, wherein a compression ratio means the ratio of the height of a billet before the pressure forming to height of the billet after the pressure forming. The above forming method allows the manufacture of a formed article having different volume contents 8 Vf) of the ceramic for different portions thereof.

Abstract: An aluminum casting process using a casting mold in which after the cavity (25) is filled with an inert gas, magnesium is introduced into the cavity to have a magnesium layer (58a) deposited on the cavity wall. Then, nitrogen gas is introduced into the cavity to form magnesium nitride (58b) on the surface of the magnesium layer after the cavity wall is heated to a specific temperature. Then, molten aluminum is supplied to have an aluminum casting molded, while the surface of the molten aluminum (39) is reduced with magnesium nitride. This makes it possible to form magnesium nitride within a short time and decrease the amount of nitrogen gas as required.

Abstract: A cast-bonding process includes a magnesium coating step and a magnesium nitride-forming step. The magnesium-coating step is carried out by supplying gasified magnesium into a mold in which a cast-in insert formed from an aluminum alloy, or an aluminum-based composite material is set, so that magnesium may coat the insert. The magnesium nitride-forming step is carried out by supplying nitrogen gas into the mold so that the coating magnesium and nitrogen gas may react to form magnesium nitride. Then, a molten aluminum alloy is poured into the mold for cast-bonding the insert.

Abstract: An aluminum casting process using a casting mold in which after the cavity (25) is filled with an inert gas, magnesium is introduced in to the cavity to have a magnesium layer (58a) deposited on the cavity wall. Then, nitrogen gas is introduced into the cavity to form magnesium nitride (58b) on the surface of the magnesium layer after the cavity wall is heated to a specific temperature. Then, molten aluminum is supplied to have an aluminum casting molded, while the surface of the molten aluminum (39) is reduced with magnesium nitride. This makes it possible to form magnesium nitride within a short time and decrease the amount of nitrogen gas as required.

Abstract: A method of feeding a blank (31) by cutting a billet (11) for plastic working includes the steps of superimposing a plurality of annular members (15 to 18) having a coefficient of linear expansion smaller than that of the billet and an inside diameter slightly greater than the outside diameter of the billet on one another to assemble a tubular jig (12), inserting the billet into the assembled jig, heating the billet and the jig to a temperature at which the billet is half-molten, and cutting the billet into at least one blank by moving the annular members adjacent to one another in opposite directions. The cutting of the billet does not need a cutting tool, thus causing no wear of blades, and thereby allowing reduction in production cost. The billet can be cut into a plurality of pieces at a time, increasing productivity. Since the blanks can be fed together with the annular members, there is no need to reheat the blanks, providing increased productivity.

Abstract: An aluminum casting process using a casting mold in which after the cavity (25) is filled with an inert gas, magnesium is introduced into the cavity to have a magnesium layer (58a) deposited on the cavity wall. Then, nitrogen gas is introduced into the cavity to form magnesium nitride (58b) on the surface of the magnesium layer after the cavity wall is heated to a specific temperature. Then, molten aluminum is supplied to have an aluminum casting molded, while the surface of the molten aluminum (39) is reduced with magnesium nitride. This makes it possible to form magnesium nitride within a short time and decrease the amount of nitrogen gas as required.

Abstract: A brake drum has its strength elevated in its disk portion. The brake drum is formed from a composition having ceramics dispersed in a matrix. The disk portion has a high ceramic content and thereby a high strength. Its cylindrical portion has a ceramic content decreasing gradually from the outer edge of the disk portion.

Abstract: An aluminum casting method includes the step of applying in advance a mold release agent including magnesium to a mold surface. Thereafter, a nitrogen gas is injected into a cavity to cause reaction between the magnesium in the surface of the mold release agent and the nitrogen gas, thereby forming magnesium nitride. Since the nitrogen gas reacts only with the magnesium exposed in the surface of the mold release agent, the forming time of the magnesium nitride is reduced and also the amount of nitrogen gas used is reduced.

Abstract: A brake drum includes a ring-shaped drum body (13), and a friction member (16) secured to the inner circumferential surface (18) of the drum body. Because the drum body is formed of a lightweight Al alloy and the friction member is formed of an Al-base composite material, the brake drum can be reduced in weight as a whole. Further, because the friction member, having projecting portions (17a) formed on its outer periphery (17), is cast-enveloped by molten metal of the Al alloy, the friction member and the drum body can be firmly fastened together. Thus, even when a great braking force is applied to the drum brake, the friction member can be prevented from being undesirably detached from the drum body.

Abstract: A brake drum includes a ring-shaped drum body, and a friction member secured to the inner circumferential surface of the drum body. Because the drum body is formed of a lightweight Al alloy and the friction member is formed of an Al-base composite material, the brake drum can be reduced in weight as a whole. Further, because the friction member, having projection portions formed on its outer periphery, is cast enveloped by molten metal of the Al alloy, the friction member and the drum body can be firmly fastened together. Thus, even when a great braking force is applied to the drum brake, the friction member can be prevented from being undesirably detached from the drum body.

Abstract: A method for injection molding a metallic material is disclosed in which an injecting material comprised of a half-solidified metallic material and a molten metallic material is injected into a cavity of a die from an injection cylinder through a gate thereof. A non-product portion remaining at the gate of the die is separated from a product portion while it is still hot. The separated high-temperature non-product portion is press-formed into a billet in the injection cylinder. Utilization of heat from the injecting material in melting the high-temperature billet enables reuse of the non-product portion remained at the gate and reduction of heat energy required in melting the billet.

Abstract: An aluminum casting process using a casting mold in which after the cavity (25) is filled with an inert gas, magnesium is introduced into the cavity to have a magnesium layer (58a) deposited on the cavity wall. Then, nitrogen gas is introduced into the cavity to form magnesium nitride (58b) on the surface of the magnesium layer after the cavity wall is heated to a specific temperature. Then, molten aluminum is supplied to have an aluminum casting molded, while the surface of the molten aluminum (39) is reduced with magnesium nitride. This makes it possible to form magnesium nitride within a short time and decrease the amount of nitrogen gas as required.

Abstract: An aluminum casting method includes the step of applying in advance a mold release agent including magnesium to a mold surface. Thereafter, a nitrogen gas is injected into a cavity to cause reaction between the magnesium in the surface of the mold release agent and the nitrogen gas, thereby forming magnesium nitride. Since the nitrogen gas reacts only with the magnesium exposed in the surface of the mold release agent, the forming time of the magnesium nitride is reduced and also the amount of nitrogen gas used is reduced.

Abstract: A method of feeding a blank (31) by cutting a billet (11) for plastic working includes the steps of superimposing a plurality of annular members (15 to 18) having a coefficient of linear expansion smaller than that of the billet and an inside diameter slightly greater than the outside diameter of the billet on one another to assemble a tubular jig (12), inserting the billet into the assembled jig, heating the billet and the jig to a temperature at which the billet is half-molten, and cutting the billet into at least one blank by moving the annular members adjacent to one another in opposite directions. The cutting of the billet does not need a cutting tool, thus causing no wear of blades, and thereby allowing reduction in production cost. The billet can be cut into a plurality of pieces at a time, increasing productivity. Since the blanks can be fed together with the annular members, there is no need to reheat the blanks, providing increased productivity.

Abstract: A cast-bonding process includes a magnesium coating step and a magnesium nitride-forming step. The magnesium-coating step is carried out by supplying gasified magnesium into a mold in which a cast-in insert formed from an aluminum alloy, or an aluminum-based composite material is set, so that magnesium may coat the insert. The magnesium nitride-forming step is carried out by supplying nitrogen gas into the mold so that the coating magnesium and nitrogen gas may react to form magnesium nitride. Then, a molten aluminum alloy is poured into the mold for cast-bonding the insert.