Abstract: Discontinuous fiber preforms, fiber-reinforced metal matrix composites, and methods of making same are disclosed. A fiber preform includes a milled fiber material having a weighted average fiber length of about 0.03 mm to 0.12 mm and/or a percent fiber volume fraction of the fiber preform of about 15% to about 55%. The milled fiber material is at least substantially free of a binder material. A fiber-reinforced MMC includes a milled fiber material having a weighted-average fiber length of about 0.03 mm to 0.12 mm and/or a percent fiber volume fraction of the fiber preform of about 15% to about 55%. The fiber-reinforced MMC further includes a metal infiltrated into the milled fiber material. The milled fiber material is at least substantially free of a binder material. The milled fiber can be substantially uniformly oriented and/or randomly oriented in the fiber preform and/or the fiber-reinforced MMC.

Abstract: Discontinuous fiber preforms, fiber-reinforced metal matrix composites, and methods of making same are disclosed. A fiber preform includes a milled fiber material having a weighted average fiber length of about 0.03 mm to 0.12 mm and/or a percent fiber volume fraction of the fiber preform of about 15% to about 55%. The milled fiber material is at least substantially free of a binder material. A fiber-reinforced MMC includes a milled fiber material having a weighted-average fiber length of about 0.03 mm to 0.12 mm and/or a percent fiber volume fraction of the fiber preform of about 15% to about 55%. The fiber-reinforced MMC further includes a metal infiltrated into the milled fiber material. The milled fiber material is at least substantially free of a binder material. The milled fiber can be substantially uniformly oriented and/or randomly oriented in the fiber preform and/or the fiber-reinforced MMC.

Abstract: A containerless method of producing a crack free metallic article of near-net shape includes melting a filler material into a metallic substrate or seed under conditions chosen to preclude cracking. In a preferred embodiment of the invention, a laser beam is operated at a relatively low power density and at a relatively large beam diameter at the substrate surface for an extended length of time to produce a molten pool with a low aspect ratio. Near-net shape is achieved by applying the process in a closed-loop, multi-axis material deposition system.

Abstract: A filler material is melted into a metallic substrate having a defect under conditions chosen to preclude cracking. In a preferred embodiment of the invention, a laser beam is operated at a relatively low power density and at a relatively large diameter for an extended length of time to produce a molten pool with a low aspect ratio.

Abstract: A containerless method of producing a crack free metallic article of near-net shape includes melting a filler material into a metallic substrate or seed under conditions chosen to preclude cracking. In a preferred embodiment of the invention, a laser beam is operated at a relatively low power density and at a relatively large beam diameter at the substrate surface for an extended length of time to produce a molten pool with a low aspect ratio. Near-net shape is achieved by applying the process in a closed-loop, multi-axis material deposition system.