| 摘要 |
PURPOSE: To impart an excellent rigidity at high temperature by specifying the composition of an aluminum alloy and forming a dispersed structure of a fine Si phase. CONSTITUTION: The alloy is such that the composition in wt.% is 14.0-20.0% Si, 1.0-4.0% Cu, 1.0-2.0% Mg, 0.3-1.4% Fe, 0.5-1.5% Ni, 0.04-0.2% Ti and the balance Al with inevitable impurities, and that is provided with a dispersed structure of Si phase of 2.5μm or less. Desirably, this structure is further made to contain 0.1-0.7% Mn, 0.1-0.3% Zr and 0.05-0.5% V. The alloy is manufactured in accordance with a half-melted solidification method by means of ordinary mechanical stirring or electromagnetic stirring. In addition, in order to secure strength at high temperature, the heat treatment is performed with a solution treatment at (solidus line temp. -5) deg.C to (solidus line temp. -25) deg.C and aging processing for 5 to 20 hours at 160-240 deg.C. Thus, the process brings a yield strength of 205N/mm<2> or above and a Young's modulus of 73GPa or above at 200 deg.C temp.
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