To provide a titanium sheet excellent in formability and a method for manufacturing the same. A titanium sheet, wherein, when a carbon concentration of a base material is C.sub.b (mass %) and a carbon concentration at a depth d m from a surface is C.sub.d (mass %), the depth d (carbon concentrated layer thickness) satisfying C.sub.d/C.sub.b>1.5 is 1.0 m or more and less than 10.0 m or less, wherein a Vickers hardness HV.sub.0.025 at a load of 0.245 N in the surface is 200 or more, a Vickers hardness HV.sub.0.05 at a load of 0.49 N in the surface is lower than HV.sub.0025, and a difference between HV.sub.0.025 and HV.sub.0.05 is 30 or more, wherein a Vickers hardness HV.sub.1 at a load of 9.8 N in the surface is 150 or less, and wherein an average interval between cracks generated in the surface when a strain of 25% is given in a rolling direction in a bulging forming process is less than 50 m and a depth thereof is 1 m or more and less than 10 m.

Method of treating a workpiece comprising a titanium metal, wherein a titanium metal surface layer of the workpiece is converted to titanium nitrides. The method comprises the following steps; a) heating the workpiece to an initial nitriding temperature (T.sub.n1) and b) subjecting said workpiece to one or more nitriding temperatures (T.sub.n1, T.sub.n2) for predetermined time(s) in a nitrogen containing gas under high pressure at hot isostatic pressing (HIP) conditions for converting the titanium metal surface layer to a first layer portion consisting of titanium nitrides and a second layer portion comprising a nitrogen gradient in the titanium metal. The method further comprises c) quenching the workpiece in the nitrogen containing gas under high pressure at hot isostatic pressing (HIP) conditions, in order to strengthen the titanium metal below the in step b) formed first nitride layer portion.

Method of treating a workpiece comprising a titanium metal, wherein a titanium metal surface layer of the workpiece is converted to titanium nitrides. The method comprises the following steps; a) heating the workpiece to an initial nitriding temperature (T.sub.n1) and b) subjecting said workpiece to one or more nitriding temperatures (T.sub.n1, T.sub.n2) for predetermined time(s) in a nitrogen containing gas under high pressure at hot isostatic pressing (HIP) conditions for converting the titanium metal surface layer to a first layer portion consisting of titanium nitrides and a second layer portion comprising a nitrogen gradient in the titanium metal. The method further comprises c) quenching the workpiece in the nitrogen containing gas under high pressure at hot isostatic pressing (HIP) conditions, in order to strengthen the titanium metal below the in step b) formed first nitride layer portion.

Functional materials and methods for making the functional materials are provided. Also provided are methods for utilizing the functional materials in a variety of applications, including catalysis, adsorption, energy storage, and biomedical applications. The functional materials are made from metal alloys via an oxidative dealloying process that selectively removes one or more elements from the metal alloy and converts one or more of the remaining elements into a stable metal-oxygen matrix having a controlled porosity.

Functional materials and methods for making the functional materials are provided. Also provided are methods for utilizing the functional materials in a variety of applications, including catalysis, adsorption, energy storage, and biomedical applications. The functional materials are made from metal alloys via an oxidative dealloying process that selectively removes one or more elements from the metal alloy and converts one or more of the remaining elements into a stable metal-oxygen matrix having a controlled porosity.

A method of modifying the physical characteristics of a base titanium alloy article previously manufactured through a selective melting process is disclosed. The method includes introducing hydrogen through a thermohydrogen process to the base titanium alloy article, the resulting titanium alloy article exhibiting an isotropic and fine grained equiaxed microstructure. The thermohydrogen process may include introducing hydrogen into the base titanium alloy article to lower the beta transus temperature, heating the base titanium article above the lowered beta transus temperature to form hydrided beta, lowering the temperature of the base titanium alloy article to affect a eutectoid transformation, and dehydriding the base titanium alloy article via vacuum heating. The base titanium alloy article may have an elevated oxygen content and/or hydrogen may be introduced at 0.4 weight percent or greater.

A method of modifying the physical characteristics of a base titanium alloy article previously manufactured through a selective melting process is disclosed. The method includes introducing hydrogen through a thermohydrogen process to the base titanium alloy article, the resulting titanium alloy article exhibiting an isotropic and fine grained equiaxed microstructure. The thermohydrogen process may include introducing hydrogen into the base titanium alloy article to lower the beta transus temperature, heating the base titanium article above the lowered beta transus temperature to form hydrided beta, lowering the temperature of the base titanium alloy article to affect a eutectoid transformation, and dehydriding the base titanium alloy article via vacuum heating. The base titanium alloy article may have an elevated oxygen content and/or hydrogen may be introduced at 0.4 weight percent or greater.

A gold alloy and a method for producing the gold alloy. The gold alloy includes: gold; and an AuX-RE-based hypermaterial represented by a compositional formula AU.sub.100-(a+b)X.sub.aRE.sub.b, wherein, in the compositional formula, X represents at least one atom selected from the group consisting of Al, Ga, In, Si, Ge, and Sn; RE represents a rare-earth element; and a and b respectively represent a content of X and a content of RE, expressed in at %, and satisfy the following (1) and (2): 10?a?40 (1); and 13?b?17 (2), wherein the AuX-RE-based hypermaterial is dispersed in a gold matrix phase.

A steam turbine rotor blade achieving both abrasion resistance and reliability, and a method for manufacturing a steam turbine rotor blade capable of obtaining such a steam turbine rotor blade are provided. A steam turbine rotor blade according to the invention is characterized by including a blade base material and an erosion shield formed on a surface of the blade base material, wherein the blade base material is composed of a titanium alloy, and the erosion shield is composed of a weld overlay layer including a parent phase composed of pure titanium in which a metal element is solid-dissolved or a titanium alloy in which a metal element is solid-dissolved, and a hard phase dispersed in the parent phase.

A steam turbine rotor blade achieving both abrasion resistance and reliability, and a method for manufacturing a steam turbine rotor blade capable of obtaining such a steam turbine rotor blade are provided. A steam turbine rotor blade according to the invention is characterized by including a blade base material and an erosion shield formed on a surface of the blade base material, wherein the blade base material is composed of a titanium alloy, and the erosion shield is composed of a weld overlay layer including a parent phase composed of pure titanium in which a metal element is solid-dissolved or a titanium alloy in which a metal element is solid-dissolved, and a hard phase dispersed in the parent phase.