PROCESS FOR PRODUCING BRAKE PISTON

Title:

PROCESS FOR PRODUCING BRAKE PISTON

Document Type and Number:

WIPO Patent Application WO/2011/046196

Kind Code:

A1

Abstract:

A brake piston having required mechanical strength is produced through fewer steps than in conventional processes. An aluminum alloy having an Si concentration (CSi, mass%) and an Mg concentration (CMg, mass%) which are within the range surrounded by the four points A(0.75, 1.25), B(1.4, 1), C(1.4, 0.6), and D(0.75, 0.85) in terms of relationship therebetween (CSi, CMg) and further having a Cu concentration of 0.07-0.9 mass%, an Mn concentration of 0.1-0.9 mass%, a Ti concentration of 0.005-0.15 mass%, a Cr concentration of 0.2 mass% or less, and an Fe concentration of 0.5 mass%, the remainder comprising Al and incidental impurities, is cast to obtain a rod-shaped ingot. The rod-shaped ingot, without being subjected to homogenizing, is straightened within 3 days after the casting. The straightened rod-shaped ingot is cut into a given thickness to obtain a material to be forged. This material, without being subjected to annealing, is cold-forged within 7 days after the casting of the rod-shaped ingot at a reduction ratio of 25-90% to shape the material into a cup, which is subjected to age hardening without being subjected to solution heat treatment.

Inventors:

OKAMOTO YASUO (JP)

Application Number:

PCT/JP2010/068124

Publication Date:

April 21, 2011

Filing Date:

October 15, 2010

Export Citation:

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Assignee:

SHOWA DENKO KK (JP)
OKAMOTO YASUO (JP)

International Classes:

C22F1/05; B21J5/00; B21K1/18; B22D11/00; B22D11/20; C22C21/02; C22C21/06

Foreign References:

JPH10183287A	1998-07-14
JP2002294383A	2002-10-09
JPH1143798A	1999-02-16

Other References: