MANUFACTURE OF HEAT RESISTANT ALUMINUM ALLOY WITH HIGH ELECTRIC CONDUCTIVITY

摘要

PURPOSE:To manufacture the titled alloy maintaining prescribed tensile strength by melting an Al alloy contg. Zr, Si and Fe, casting the molten alloy at a high cooling rate, working the ingot under rapid cooling to reduce the area, and carrying out 2-stage heat treatment at a lower temp. and a higher temp. CONSTITUTION:An alloy consisting of 0.2-1.5% Zr, 0.04-0.5% Si and/or Fe and the balance essentially Al is melted and cast under cooling at =5 deg.C/sec cooling rate. Without carrying out reheating, the ingot is worked at =80% reduction of area under cooling at =5 deg.C/sec cooling rate until the finishing temp. becomes =200 deg.C. The worked ingot is subjected to a primary heat treatment at 250- 400 deg.C for 0.5-30hr and a secondary heat treatment at 300-500 deg.C for 1-50hr. At this time, the latter temp. is made higher than the former temp. The heat treated ingot is then cold worked to obtain a heat resistant Al alloy with high electric conductivity.