| 摘要 |
PROBLEM TO BE SOLVED: To provide an aluminum alloy casting increased in strength and toughness and having mechanical properties equal to those of forged materials, independently of wall thickness, by specifying alloy composition and casting pressure, respectively, and regulating the size of solidified cells in a structure to a specific value or below. SOLUTION: A molten Al alloy, having a composition consisting of, by weighty, 6-1.0% Si, 0.6-1.2% Cu, 0.8-1.2% Mg, 0.4-1.2% Zn, 0.01-0.20% Ti, 0.002-0.015% B, and the balance Al, is filled into a metal mold. This molten alloy is solidified under a pressure as high as >=500kgf/cm<2> , and the size of the resultant solidified cells as metallic structure is regulated to <=60μm at the maximum. By this method, the occurrence of shrinkage cavity and casting crack can be prevented and the metallic structure in respective parts of the resultant casting can be refined and mechanical properties, particularly elongation value, can be improved, and as a result, the aluminum alloy casting, excellent in strength and toughness, can be obtained by means of high pressure casting.
|
