Title:
The surface modification method of the piston for internal-combustion engines, and the piston for internal-combustion engines
Document Type and Number:
Japanese Patent JP6001989
Kind Code:
B2
Abstract:
Provided is a piston for internal combustion engines which suffers no decrease in strength even in high-temperature environments. In a space in which oxygen is present, an aluminum-silicon alloy piston for internal combustion engines is subjected to a first jetting treatment in which iron-based alloy shots having a particle diameter of 20-200 µm, a thermal conductivity at 25°C of 30 W/m·k or less, and a specific gravity of 7.5 g/cm 3 or higher are jetted against the surface of the piston under the conditions of an arc height value of 0.07-0.13 mm(N) and successively to a second jetting treatment in which the shots are jetted against the piston surface under the conditions of an arc height value of 0.13-0.22 mm(N). Thereafter, a heat treatment is given to the piston surface at 170-190°C for 1.5 hours or longer in the presence of oxygen to form a surface modification layer in the range from the outermost surface to a depth of about 30 µm, the layer having a structure that includes an intergranular oxide constituted of an oxide of an aluminum-iron alloy at the boundaries of crystal grains of aluminum and/or an aluminum-based alloy.
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Inventors:
Nobuyuki Fujiwara
Shio Miyasaka
Shio Miyasaka
Application Number:
JP2012224359A
Publication Date:
October 05, 2016
Filing Date:
October 09, 2012
Export Citation:
Assignee:
Art Metal Industry Co., Ltd.
Fuji Machine Sales Co., Ltd.
Fuji Machine Sales Co., Ltd.
International Classes:
C23C10/28; B24C1/10; F02F3/00; F16J1/02
Domestic Patent References:
| JP200851091A | ||||
| JP2002301663A | ||||
| JP586443A | ||||
| JP201090812A |
Attorney, Agent or Firm:
Masaaki Ogura
Tetsuro Tomura
Tetsuro Tomura