| 摘要 |
<p>The invention provides a cast bar of an aluminum base alloy for forging. The bar exhibit high tensile strength, impact resistance and fatigue strength and comprises 2.0 to 9.0 wt.% of copper, 0.2 to 1.2 wt% of magensium, 0.2 to 1.2 wt.% of silicon, 0.2 to 0.8 wt.% of manganese, and optionally, titanium or titanium and boron in a total amount of from 0.005 to 0.15 wt.%. The balance consists of aluminum and unavoidable impurities, and the grain diameter is not greater than 80 .mu.m, the second dendrite are spacing is not greater than 15 .mu.m and the second phase particles comprising intermetallic compounds have a size not greater than 10 .mu.m. A process is also provided for producing a cast bar of an aluminum base alloy which comprises 2.0 to 9.0 wt.% of copper, 0.2 to 1.2 wt% of magnesium, 0.2 to 1.2 wt.% of silicon 0 2 to 0.8 wt.% of manganese, and optionally, titanium or titanium and boron in a total amount of from 0.005 to 0.15 wt.%. The process comprises preparing a melt of the alloy composition and continuously casting the melt at a solidification speed of not lower than 25.degree.C./sec. The products of the invention are of homogeneous structure, are free of defects, exhibit excellent mechanical properties and can be subjected, as cast, or after a heat treatment, to a working operation such as forging.</p> |
