Abstract
An aluminum alloy, 2024, has been mechanically alloyed with nickel to investigate the effects of three process control agents, i.e., zinc stearate, amorphous carbon and graphite, on milling process and powder characteristics. In milling aluminum powders, some process control agent must be used so that a balance between cold welding and fracturing is obtained. Zinc stearate has turned out to be a suitable additive for controlling milling processes. The influences of process control agents on mechanical property were assessed in tensile tests of extrudates of the mechanically alloyed powders. It was found that carbon and graphite gave good tensile strengths both at ambient temperature and at elevated temperatures. Although zinc stearate gave good room temperature tensile strengths, it was not so effective to improve elevated temperature strengths. It was found that the combined addition of process control agents offered a way to comply with various demands; for example, good control characteristics of milling process with excellent high-temperature strengths on the extrudates were achieved by a combined addition of zinc stearate and carbon.
