The disclosure relates to a method for producing a component, in particular a vehicle component or an engine component, such as a piston of an internal combustion engine. The method comprises forming a first body region, in particular by means of casting or forging. The method includes forming a second body region, which is connected to the first body region, from an aluminium alloy or an iron-based alloy or a copper-based alloy by means of an additive manufacturing method. The second body region is alloyed in such a manner that it has higher thermal stability, higher mechanical strength or higher wear resistance upon tribological stressing than the first body region.

There is provided a cobalt-based alloy product comprising: in mass %, 0.08-0.25% C; 0.1% or less B; 10-30% Cr; 5% or less Fe and 30% or less Ni, the total amount of Fe and Ni being 30% or less; W and/or Mo, the total amount of W and Mo being 5-12%; 0.5% or less Si; 0.5% or less Mn; 0.003-0.04% N; 0.5 to 2 mass % of an M component being a transition metal other than W and Mo and having an atomic radius of more than 130 pm; and the balance being Co and impurities. The impurities include 0.5% or less Al and 0.04% or less O. The product is a polycrystalline body of matrix phase crystal grains. In the matrix phase crystal grains, segregation cells with an average size of 0.13-2 μm are formed, in which the M component is segregated in boundary regions of the segregation cells.

Described herein are additive manufacturing methods and products made using such methods. The alloy compositions described herein are specifically selected for the additive manufacturing methods and provide products that exhibit superior mechanical properties as compared to their cast counterparts. Using the compositions and methods described herein, products that do not exhibit substantial coarsening, such as at elevated temperatures, can be obtained. The products further exhibit uniform microstructures along the print axis, thus contributing to improved strength and performance. Additives also can be used in the alloys described herein.

Provided are: an alloy member that is excellent in homogeneity of both the alloy composition and microstructure and excellent in shape controllability and includes a high entropy alloy having high mechanical properties and high corrosion resistance, a process for producing the same, and a product including the alloy member. In the present invention, the alloy member having a chemical composition comprising elements of Co, Cr, Fe, Ni, and Ti each in an amount within a range of 5 atomic % or more and 35 atomic % or less and Mo in an amount within a range of more than 0 atomic % and 8 atomic % or less, the reminder consisting of unavoidable impurities, wherein ultrafine grains having an average grain diameter of 100 nm or less are dispersed and precipitated in a parent phase crystal.

Provided are: an alloy member that is excellent in homogeneity of both the alloy composition and microstructure and excellent in shape controllability and includes a high entropy alloy having high mechanical properties and high corrosion resistance, a process for producing the same, and a product including the alloy member. In the present invention, the alloy member having a chemical composition comprising elements of Co, Cr, Fe, Ni, and Ti each in an amount within a range of 5 atomic % or more and 35 atomic % or less and Mo in an amount within a range of more than 0 atomic % and 8 atomic % or less, the reminder consisting of unavoidable impurities, wherein ultrafine grains having an average grain diameter of 100 nm or less are dispersed and precipitated in a parent phase crystal.

Metallic matrix composites include a high strength titanium aluminide alloy matrix and an in situ formed aluminum oxide reinforcement. The atomic percentage of aluminum in the titanium aluminide alloy matrix can vary from 40% to 48%. Included are methods of making the metallic matrix composites, in particular, through the performance of an exothermic chemical reaction. The metallic matrix composites can exhibit low porosity.

A sintered bearing is made of a sintered compact containing nickel silver (Cu—Ni—Zn) as a base. In the sintered bearing, P is not added in the sintered compact. Alternatively, a content of P in the sintered compact is less than 0.05 mass % in terms of mass ratio to a total mass. Consequently, crystal grains constituting the sintered compact can be micronized. In particular, in the sintered bearing, an average crystal particle diameter of the crystal grains constituting the sintered compact is 20 μm or less. Consequently, the mechanical strength and the vibration resisting properties can be improved, and the rotation shaft can be prevented from being damaged.

The invention relates to a method for producing a semi-finished product comprising a foamable core comprising a foamable mixture that comprises at least one first metal having an aluminum content of at least approximately 80 wt. %, in relation to the quantity of the at least one first metal, and at least one foaming agent, wherein a layer of at least one second metal in the form of a non-foamable solid material and with an aluminum content of at least approximately 80 wt. %, in relation to the quantity of the at least one second metal, is respectively applied to at least one first and second surface of the core. The invention also relates to a corresponding semi-finished product and to the use of such a semi-finished product for foaming a metal.

There is provided a cobalt-based alloy product comprising: in mass %, 0.08-0.25% C; 0.1% or less B; 10-30% Cr; 5% or less Fe and 30% or less Ni, the total amount of Fe and Ni being 30% or less; W and/or Mo, the total amount of W and Mo being 5-12%; at least one of Ti, Zr, Hf, V, Nb and Ta, the total amount of Ti, Zr, Hf, V, Nb and Ta being 0.5-2%; 0.5% or less Si; 0.5% or less Mn; 0.003-0.04% N; and the balance being Co and impurities. The product is a polycrystalline body of matrix phase crystal grains. In the matrix phase crystal grains, post-segregation cells with an average size of 0.13-2 μm are formed, wherein components constituting an MC type carbide phase comprising Ti, Zr, Hf, V, Nb and/or Ta are segregated along boundary regions of the post-segregation cells.

An aluminum-based composite material includes a plurality of coarse crystalline grains (3) of pure aluminum, and a plurality of fine crystalline grains (4) each having an aluminum matrix (1), and a dispersion material (2) dispersed inside the aluminum matrix and formed by reacting a portion or all of an additive with aluminum in the aluminum matrix. The fine crystalline grains exist among the coarse crystalline grains, and the fine crystalline grains have crystalline grain diameters smaller than crystalline grain diameters of the coarse crystalline grains.