A niobium or niobium alloy which contains pure or substantially pure niobium and at least one metal element selected from the group consisting of Ru, Rh, Pd, Os, Ir, Pt, Mo, W and Re to form a niobium alloy that is resistant to aqueous corrosion. The invention also relates to the process of preparing the niobium alloy.

An object of the present invention is to provide a molten ingot of a platinum group metal or a platinum group-based alloy having a high material yield by suppressing a scattering phenomenon during heating and melting in a method for producing a platinum group metal or a platinum group-based alloy. The method for producing a platinum group metal or a platinum group-based alloy according to the present invention includes a preparing step of weighing a raw material that is partially or entirely of powder and, when the alloy is to be produced, mixing the weighed raw material to obtain a powder mixture, a molding step of molding and solidifying the prepared raw material to obtain molded bodies, a sintering step of sintering the molded bodies to obtain a sintered body, a melting step of melting the sintered body to produce a molten ingot, and a deformation processing step of processing the molten ingot. In the sintering step, the molded bodies are sintered in a stacked state to produce a sintered body as a joined body.

An object of the present invention is to provide a molten ingot of a platinum group metal or a platinum group-based alloy having a high material yield by suppressing a scattering phenomenon during heating and melting in a method for producing a platinum group metal or a platinum group-based alloy. The method for producing a platinum group metal or a platinum group-based alloy according to the present invention includes a preparing step of weighing a raw material that is partially or entirely of powder and, when the alloy is to be produced, mixing the weighed raw material to obtain a powder mixture, a molding step of molding and solidifying the prepared raw material to obtain molded bodies, a sintering step of sintering the molded bodies to obtain a sintered body, a melting step of melting the sintered body to produce a molten ingot, and a deformation processing step of processing the molten ingot. In the sintering step, the molded bodies are sintered in a stacked state to produce a sintered body as a joined body.

System and method for welding a precipitation-hardened superalloy, e.g., Nickel-based superalloy, article to produce a weld joint, wherein one or more sections are defined longitudinally within the entire length of the weld joint to be produced, melting of superalloy material adjacent the weld joint to be produced in one of the one or more sections is subsequently performed, by directing a power beam towards the section and longitudinally oscillating the power beam within the section, an intensity of the power beam and a frequency of oscillation of the power beam are selected such that the superalloy material adjacent the weld joint to be produced are caused to become uniformly heated and melt thereby producing the weld joint from the consolidation of the superalloy material so melted, where the weld joint is thereafter solidified by gradually reducing the power beam intensity while oscillating longitudinally the power beam within the section.

A tantalum or tantalum alloy which contains pure or substantially pure tantalum and at least one metal element selected from the group consisting of Ru, Rh, Pd, Os, Ir, Pt, Mo, W and Re to form a tantalum alloy that is resistant to aqueous corrosion. The invention also relates to the process of preparing the tantalum alloy.

A tantalum or tantalum alloy which contains pure or substantially pure tantalum and at least one metal element selected from the group consisting of Ru, Rh, Pd, Os, Ir, Pt, Mo, W and Re to form a tantalum alloy that is resistant to aqueous corrosion. The invention also relates to the process of preparing the tantalum alloy.

A free-cutting titanium material and a preparation process thereof are provided. The free-cutting titanium material includes a matrix component group and a free-cutting component group, and at least one free-cutting component group is added to the matrix component group; the matrix component group includes the following in percentage by mass: iron (Fe): 0-1.0%; nitrogen (N): 0-0.08%; hydrogen (H): 0-0.02%; oxygen (O): 0-0.50%; aluminium (Al): 0-8.0%; vanadium (V): 0-15.0%, and a balance being titanium and unavoidable impurities; and the free-cutting component group respectively refers to: a rare earth (RE) and sulfur (S) group, a copper (Cu) and S group, a zirconium (Zr) group, a carbon (C) group, a boron (B) group, or a magnesium (Mg) group. The free-cutting titanium material is prepared by any one of three methods: vacuum consumable melting, vacuum suspension melting, and powder metallurgy. The present disclosure enhances the machinability of the titanium material.

A free-cutting titanium material and a preparation process thereof are provided. The free-cutting titanium material includes a matrix component group and a free-cutting component group, and at least one free-cutting component group is added to the matrix component group; the matrix component group includes the following in percentage by mass: iron (Fe): 0-1.0%; nitrogen (N): 0-0.08%; hydrogen (H): 0-0.02%; oxygen (O): 0-0.50%; aluminium (Al): 0-8.0%; vanadium (V): 0-15.0%, and a balance being titanium and unavoidable impurities; and the free-cutting component group respectively refers to: a rare earth (RE) and sulfur (S) group, a copper (Cu) and S group, a zirconium (Zr) group, a carbon (C) group, a boron (B) group, or a magnesium (Mg) group. The free-cutting titanium material is prepared by any one of three methods: vacuum consumable melting, vacuum suspension melting, and powder metallurgy. The present disclosure enhances the machinability of the titanium material.