The invention relates to a method for producing a sintered component comprising the steps: providing a metallic powder; filling the powder into a powder press; pressing the powder to form a green compact; removing the green compact from the powder press; sintering the green compact into a sintered component with pores; optional redensification of the sintered component; hardening of the sintered component, wherein the pores of the sintered component, prior to hardening at least in that region of the surface of the sintered component which is subjected to a hardening, are at least partially filled with a filling agent.

Metal components subject to wear or contact fatigue in a first area, and subject to bending, axial and/or torsional stress loading in a second area comprise a surface hardened, first surface layer in the first area, and a surface compressive-stress treated, second surface layer in the second area. The second surface layer has a material hardness different from, and typically lower than, the first surface layer, and induced residual compressive stress to improve fatigue strength. Example components described include a gear, a cog, a pinion, a rack, a splined shaft, a splined coupling, a torqueing tool and a nut driving tool. A hybrid manufacturing process is described, including area-selective surface hardening combined with a process to add compressive stress to fatigue failure prone areas.

Metal components subject to wear or contact fatigue in a first area, and subject to bending, axial and/or torsional stress loading in a second area comprise a surface hardened, first surface layer in the first area, and a surface compressive-stress treated, second surface layer in the second area. The second surface layer has a material hardness different from, and typically lower than, the first surface layer, and induced residual compressive stress to improve fatigue strength. Example components described include a gear, a cog, a pinion, a rack, a splined shaft, a splined coupling, a torqueing tool and a nut driving tool. A hybrid manufacturing process is described, including area-selective surface hardening combined with a process to add compressive stress to fatigue failure prone areas.

A method for volume heat treating a part having an external surface delimiting its volume, the method comprising the following steps: a. providing a laser source; b. providing the part; c. providing support means for supporting the part; d. placing said part so that it is held in position by said support means; and e. irradiating with the laser source at least one segment of the external surface of the part with a laser exposure power and duration to obtain a temperature rise in essentially the entire volume of the part.

A method for volume heat treating a part having an external surface delimiting its volume, the method comprising the following steps: a. providing a laser source; b. providing the part; c. providing support means for supporting the part; d. placing said part so that it is held in position by said support means; and e. irradiating with the laser source at least one segment of the external surface of the part with a laser exposure power and duration to obtain a temperature rise in essentially the entire volume of the part.

The present invention suppresses leakage of combustion gas from a contact surface. A cylinder head (20) is attached to a cylinder block. The surface (26) of the side of the cylinder head (20) that is attached to the cylinder block includes a first region (AH1) and a second region (AH2) that has higher hardness than the first region (AH1).

The present invention suppresses leakage of combustion gas from a contact surface. A cylinder head (20) is attached to a cylinder block. The surface (26) of the side of the cylinder head (20) that is attached to the cylinder block includes a first region (AH1) and a second region (AH2) that has higher hardness than the first region (AH1).

Provided are a silver jewelry article formed using pure silver, which has high Vickers hardness and prohibit the occurrence of discoloration and its method. Disclosed are a silver jewelry article and its method, wherein the Vickers hardness is adjusted to 60 HV or higher, and when the height of the peak of 2θ=38°±0.2° by an XRD is designated as h1, and that of 2θ=44°±0.4° is designated as h2, h2/h1 is adjusted to 0.2 or greater.

Provided are a silver jewelry article formed using pure silver, which has high Vickers hardness and prohibit the occurrence of discoloration and its method. Disclosed are a silver jewelry article and its method, wherein the Vickers hardness is adjusted to 60 HV or higher, and when the height of the peak of 2θ=38°±0.2° by an XRD is designated as h1, and that of 2θ=44°±0.4° is designated as h2, h2/h1 is adjusted to 0.2 or greater.

A manufacturing method according to one aspect includes performing a first process of refining crystal grains of the metal member, performing a second process of releasing residual stress of the metal member after the first process, and performing a third process of applying residual stress to the metal member after the second process.