单级时效对稀土铝电工圆杆组织与性能的影响

Effect of Single Stage Aging on Microstructure and Properties of Re-bearing Aluminum Electrical Round Bars

研究了耐热铝合金电工圆杆单级时效过程中时效温度和时间对铝合金力学性能和导电率的影响。采用金相显微镜及扫描电镜观察和对比了不同时效处理制度下铝合金的显微组织。结果表明,单级时效处理的温度越高,铝合金达到峰时效的时间越短,其对应的峰时效强度越低。时效初期,导电率随时效时间的延长而不断上升,且时效温度越高,第二相析出速率越快,铝合金抗拉强度和导电率的增长速率越快;时效后期,试样抗拉强度下降,而导电率升高。最佳单级时效工艺为150℃×10 h,此时导电率为62.5%IACS,抗拉强度为78.5 MPa。

The effects of aging temperature and aging time on mechanical properties and electrical conductivity of Re-bearing aluminum electrical round bars during the single-stage aging of heat-resistant aluminum alloy electrical rods were studied. The microstructures of alloys under different aging treatments were observed and compared by metallographic method and SEM. The results show that the higher the temperature of single stage aging treatment is,the shorter the time of aluminum alloy to reach the peak aging,and the lower the corresponding peak aging strength. At the early stage of aging,the electric conductivity rises with the increase of aging time,and the higher the aging temperature is,the faster the second phase precipitation rate is,and the faster the aluminum alloy＇ s tensile strength and electrical conductivity increase. At the later aging stage,the tensile strength of the sample decreases while the conductivity increases. The best single-stage aging process is 150 ℃ × 10 h,when the conductivity is62. 5% IACS,and the tensile strength is 78. 5 MPa.