螺旋通道转角挤压变形对6005铝合金静态峰时效的影响

Influence of helical channel angular pressing on static peak aging for 6005 aluminum alloy

为研究螺旋通道转角挤压变形对6005铝合金静态峰时效的影响规律,对固溶和螺旋通道转角挤压变形及不同时效工艺处理后的试样进行维氏硬度实验和差示扫描量热实验,分析了不同处理方法下的硬度变化规律和析出相及激活能。结果表明:螺旋通道转角挤压大塑性变形促进了固溶态6005铝合金中激活能相对较低的GP区和β″相的动态析出,起到了析出强化作用,使人工静态峰时效温度从180℃降低至140℃。由于位错强化、细晶强化和析出强化的共同作用,使静态峰时效硬度从65.00 HV提高至71.62 HV。同时,由于大塑性变形过程中存在动态析出相,提高了β′相和β相的静态析出温度和析出激活能,β′相的析出温度提高了25℃,析出激活能提高了12 kJ·mol^(-1),β相的析出温度提高了33℃,析出激活能提高了42 kJ·mol^(-1),使后续析出变得困难,热稳定性提高。

In order to study the influence lows of helical channel angular pressing on the static peak aging for 6005 aluminum alloy,the Vickers hardness tests and the differential scanning calorimetry tests were conducted on the specimens treated by solid solution,helical channel angular pressing and different aging processes,and the hardness change rules,precipitated phases and activation energy under different treatment methods were analyzed.The results show that the severe plastic deformation of the helical channel angular pressing pro-motes the dynamic precipitation of GP zone andβ″phase with relatively low activation energy in the solid solution 6005 aluminum alloy,which plays a role in precipitation strengthening and reduces the artificial static peak aging temperature from 180℃to 140℃.Due to the joint effects of dislocation strengthening,grain fine strengthening and precipitation strengthening,the static peak aging hardness increases from 65.00 HV to 71.62 HV.At the same time,due to the existence of dynamic precipitation phases during severe plastic deformation process,the static precipitation temperature and the precipitation activation energy ofβ′phase andβphase are increased.The precipitati-on temperature ofβ′phase is increased by 25℃,and the precipitation activation energy is increased by 12 kJ·mol^(-1),while the precipi-tation temperature ofβphase is increased by 33℃and the precipitation activation energy is increased by 42 kJ·mol^(-1),which makes the subsequent precipitation difficult and improves the thermal stability.