Cu-Ni-Si合金的时效析出与再结晶

通过分析时效期间Cu-Ni-Si合金显微硬度、导电率及微观组织的变化,研究了析出相和再结晶行为的相互作用,以期为该合金多级复合工艺的制定提供参考.研究发现,时效初期析出相对随后的再结晶过程具有强烈阻碍作用.在450、550℃较低温度时效时,合金发生原位再结晶,析出相在其体积分数略微升高或不变的情况下发生粗化;导电率上升趋势为先快后慢并趋于稳定,因而其变化曲线上无峰值出现;显微硬度则由于时效后期析出颗粒粗化,析出强化效果降低而出现峰值.在750℃高温时效时,合金发生不连续再结晶,析出相在体积分数略有降低的情况下发生粗化;导电率先快速上升后缓慢下降,因而出现峰值,而显微硬度由于析出物迅速粗化,一开始就表现为持续下降.

Aging precipitation and recrystallization of Cu-Ni-Si alloy

By analyzing the change of microhardness,electric conductivity and microstructure of Cu-Ni-Si alloy during aging, the interaction between the precipitated phase and the recrystallization was studied, which can provide reference to the alloy’s composite processs. Results show that, precipitated phase in the early aging can strongly prevent the recrystallization. When aging at low temperature of 450 ℃ and 550 ℃, the recrystallization in site happened. Precipitated phase grew under the condition of volume fraction increasing a little or unchanging. The increase of the electric conductivity was rapid at first, then slow and inclined to be stable in the end. So there was no peak in its curves. But there was peak in the microhardness curves due to the growth of the precipitated grains. When aging at high temperature of 750 ℃, the discontinuous recrystallization happened. Precipitated phase grew under the condition of volume fraction decreasing a little. Electric conductivity increased rapidly at first,then decreased slowly. So there appeared a peak in its curve. However, microhardness decreased continuously just from the beginning because the precipitated phase grew rapidly.