US 12,169,000 B2
Mechanical component and method for manufacturing mechanical component
Ayaka Yamahara, Kuwana (JP); Miyu Sato, Kuwana (JP); and Chikara Ohki, Kuwana (JP)
Assigned to NTN CORPORATION, Osaka (JP)
Appl. No. 16/955,741
Filed by NTN CORPORATION, Osaka (JP)
PCT Filed Dec. 14, 2018, PCT No. PCT/JP2018/046152
§ 371(c)(1), (2) Date Jun. 18, 2020,
PCT Pub. No. WO2019/124265, PCT Pub. Date Jun. 27, 2019.
Claims priority of application No. 2017-244284 (JP), filed on Dec. 20, 2017; and application No. 2017-244285 (JP), filed on Dec. 20, 2017.
Prior Publication US 2020/0318684 A1, Oct. 8, 2020
Int. Cl. C21D 9/40 (2006.01); F16C 33/12 (2006.01); C22C 14/00 (2006.01)
CPC F16C 33/121 (2013.01) [C21D 9/40 (2013.01); C22C 14/00 (2013.01); F16C 2204/42 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A mechanical component made of a titanium alloy and having a surface, the mechanical component comprising a plurality of primary a crystal grains and a plurality of secondary a crystal grains,
at the surface, the primary a crystal grains having an area ratio of 10% or more and 30% or less,
at the surface, the secondary a crystal grain having a major diameter of 75 μm or less and a minor diameter of 10 μm or less,
at the surface, the titanium alloy forming a solid solution including 1% by mass or more of oxygen,
wherein a titanium oxide is removed from the surface so as to expose the solid solution, and
wherein the solid solution has a hardness of 650 Hv or more at the surface.