时效处理对Cu-Ni-Be合金组织和性能的影响

Effects of Aging Process on the Microstructure and Properties of Cu-Ni-Be Alloy

采用Cu-1.7Ni-0.5Be低铍铜合金为对象,研究了时效温度和时效时间对Cu-1.7Ni-0.5Be合金的强度、电导率等性能和组织的影响。结果表明,Cu-1.7Ni-0.5Be合金经920℃×1h固溶+480℃×6h时效处理后的综合性能最佳,电导率为34.278MS/m,抗拉强度为758MPa,伸长率为21%;在0.25~10h范围内,时效初期无明显析出相,合金强化主要体现为Be原子聚集区(G.P.区)强化。随着时效时间延长,合金的析出相逐渐形成并弥散分布;时效10h时,510℃下的析出相比480℃时的析出相更为粗大。在450~510℃时效下,合金抗拉强度整体上均随着时效时间的延长先升后降,450、480、510℃达到峰值的时间分别为8、6、2h,时效温度越高达到峰时效越早;合金的电导率随着时效时间的延长,逐渐上升且增加速度逐渐变缓,合金的室温断裂方式为韧性断裂。

Effects of aging temperature and duration on the strength,electrical conductivity and microstructure of Cu-1.7Ni-0.5Be alloy were investigated by OM,SEM,EDS and tensile testing.The results indicate that the comprehensive performance of Cu-1.7Ni-0.5Be alloy is desirable after solid solution at 920℃ for 1h and aged at 480℃ for 6h,where the electrical conductivity,tensile strength and elongation reach 34.278MS/m,758MPa and 21%,respectively.In the range of 0.25~10h,absence of precipitated phase is observed at the beginning of aging,and the alloy strengthening is dominated by the G.P.region.With the increase of aging time,the precipitated phase is generated gradually and exhibits dispersed distribution.When aging for 10h,the precipitation at 510℃ is coarser than that of ones at 480℃.Under the aging temperature of 450~510℃,the tensile strength is increased at first and then decreased with the increase of aging time on the whole.The peak time of the alloy at 450℃,480℃ and 510℃ are 8h,6h and 2h,respectively.The higher the aging temperature is,the earlier the peak value appears.With the increase of aging time,the electrical conductivity is increased gradually with a slower rate.The main fracture mode is dominated by ductile fracture under normal temperature stretch.