| US 7,601,389 B2 | ||
| Metal material and method for production thereof | ||
| Mitsuo Kuwabara, Tsurugashima (Japan); Tadashi Okada, Saitama (Japan); Naoji Yamamoto, Shizuoka-ken (Japan); Masahito Hasuike, Hamamatsu (Japan); Hideo Yoshikawa, Shizuoka-ken (Japan); Michiharu Hasegawa, Mie-ken (Japan); Tetsuaki Aoki, Kumamoto-ken (Japan); Masanori Kogawa, Kumamoto-ken (Japan); Kazunori Sakamoto, Kumamoto-ken (Japan); and Keizou Tanoue, Kumamoto (Japan) | ||
| Assigned to Honda Giken Kogyo Kabushiki Kaisha, Tokyo (Japan) | ||
| Appl. No. 10/523,266 PCT Filed Jul. 31, 2003, PCT No. PCT/JP03/09737 § 371(c)(1), (2), (4) Date Nov. 09, 2005, PCT Pub. No. WO2004/013370, PCT Pub. Date Feb. 12, 2004. |
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| Claims priority of application No. 2002-225216 (JP), filed on Aug. 01, 2002; application No. 2002-225220 (JP), filed on Aug. 01, 2002; application No. 2002-225228 (JP), filed on Aug. 01, 2002; application No. 2002-225231 (JP), filed on Aug. 01, 2002; and application No. 2002-225236 (JP), filed on Aug. 01, 2002. | ||
| Prior Publication US 2006/0134453 A1, Jun. 22, 2006 | ||
| Int. Cl. B05D 1/12 (2006.01) | ||
| U.S. Cl. 427—191 [427/201] | 8 Claims |
| 1. A method of producing a metal material comprising a diffusion layer which is formed by diffusing an element into a base
material of a metal and which has a depth from a surface of said base material of not less than 0.5 mm, a concentration of
said element being gradually decreased from said surface to inside of said base material, said method comprising:
coating said surface of said base material with a coating agent, said coating agent consisting essentially of a powder of
a substance containing said element to be diffused, a reducing agent for reducing an oxide film formed on said surface of
said base material, and a solvent in which said powder of said substance and said reducing agent are dispersed or dissolved;
and
diffusing said element into said base material by heating said base material which is coated with said substance such that
the element is diffused into the base material to a depth of not less than 0.5 mm from the surface, wherein
said diffusing step causes the concentration of said element to be gradually decreased from said surface to inside of said
base material such that an interface is not formed between the base metal material and the diffusion layer, and
the surface of the base metal material having the element diffused therein is exposed outwardly after said diffusion step.
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