6063铝合金双道次热变形微观组织演变

采用Gleeble-1500热模拟试验机对6063铝合金进行双道次热轧试验,分析了合金在变形温度为300~500 ℃,应变速率为0.001~0.1 s^-1,道次间停留时间10~90 s时的流变应力和微观组织。结果表明:随着道次间停留时间增长,第二道次屈服应力减小;温度与道次间停留时间对合金的静态软化率有较大的影响。低温大应变速率短道次间停留时间下试样的强化相较多,其形貌为长条状与圆形;高温低应变速率长道次间停留时间下试样的强化相数量有所减少,其形貌以圆形为主。通过能谱分析可知,试样中的强化相以AlFeSi为主,长条状强化相为6 μm左右,圆形强化相尺寸约2 μm。

Microstructure evolution of 6063 aluminum alloy during double-pass hot deformation

Double-pass hot rolling test on 6063 aluminum alloy was carried out by using Gleeble-1500 thermal simulator. Flow stress and microstructure of the alloy when the deformation temperature was 300-500 ℃, the strain rate was 0.001-0.1 s^-1 and the residence time between passes was 10-90 s were analyzed. The results show that the yield stress of the second pass decreases with the increase of the residence time between passes, and the static softening rate of the alloy is affected by the temperature and the residence time between passes. There is more strengthening phase in the double-pass hot rolled alloy under the condition of low temperature, high strain rate and short residence time between passes, which morphology is mainly strip and round, however, when under the condition of high temperature, low strain rate and long residence time between passes, the content of the strengthening phase decreases and its morphology is mainly round. Besides, the strengthening phase in the alloy is mainly AlFeSi phase, and the strip-like phase has a length of about 6 μm and the round phase has a size of about 2 μm.