Light Rail Asynchronous Traction Motor Of Special Copper Alloys

With the background of studying copper alloy bar for asynchronism traction electromotor, a kind of copper bar and its preparation techniques are developed, and its hardness, tensile properties, electrical properties and microstructure are studied. Furthermore, the rule of structure and properties changing with heat-treatment is especially illustrated. The results show:The first, there is obvious aging strengthening effect in Cu-10Zn-0.8(Cr,Zr) alloy. The optimal preparation process of bar is extrusion-quench-cold-drawing-aging(450 "C /4hours). The tensile strength, yield strength, elongation percentage and electrical resistance rate achieved 454MPa, 400MPa, 15.9% and 4.08 u fi - cm each.The second, the strength of bar raises with increasing of the aging temperature and time, and the bar strength achieved maximum when treated by aging 450癈/4hours, then with the increasing of the aging temperature and time, it began to decrease. The electronic resistance rate of bar gradually decreases with increasing of the aging temperature and time, but after aging 450癈/4hours, it declines rarely.The third, the high strength of bar is caused by solid-solute strengthening, deformation-heat-treatment strengthening and precipitate strengthening, but the precipitate strengthening is the leading strengthening mechanism. The reversion and precipitation of the second phase which occurs during the course of aging result in electronic conductivity reversion of bar.The fourth, in the process of aging treatment, reversion, precipitation and recrystallizing occurs successively, they interact and impact each other, and decide the structure and properties changing of bar. As Cu-10Zn-0.8(Cr,Zr) is concerned, precipitation precedes recrystallizing and put off recrystallizing.