采用Gleeble-3500热模拟试验机对5005铝合金材料进行热压缩试验,应变速率为0.01~10 s^(-1),变形温度为300~500℃,研究了材料的流动应力,并建立了本构方程。研究结果表明:在本实验中,5005铝合金具有负温度敏感性和正应变速率敏感性。变...采用Gleeble-3500热模拟试验机对5005铝合金材料进行热压缩试验,应变速率为0.01~10 s^(-1),变形温度为300~500℃,研究了材料的流动应力,并建立了本构方程。研究结果表明:在本实验中,5005铝合金具有负温度敏感性和正应变速率敏感性。变形初期,流动应力随变形程度的增加而迅速升高,达到峰值后,逐渐趋于平缓,此时流变曲线表现为稳态流变特征;该铝合金的热压缩流动应力可用包含Zener-Hollomon参数的双曲正弦关系来描述,其热变形激活能Q为180.69 k J·mol^(-1)。展开更多
The effect of stress on the microstructure and properties of an Al-Cu-Mg-Ag alloy under-aged at 165 ℃ for 2 h during thermal exposure at 200 ℃ was investigated. The tensile experimental results show that the remaine...The effect of stress on the microstructure and properties of an Al-Cu-Mg-Ag alloy under-aged at 165 ℃ for 2 h during thermal exposure at 200 ℃ was investigated. The tensile experimental results show that the remained tensile strength of both specimens at room temperature after being exposed at 200 ℃ with and without applying stress rises firstly, and then drops with the increasing of exposure time. The peak value of the remained strength reaches 439 MPa for non-stress-exposure for 10 h, and 454 MPa after being exposed with stress loaded for 20 h at 220 MPa. The elongation change is similar to that of strength. After being exposed for 100 h, specimen exposed at 220 MPa still remains a tensile strength of 401 MPa, larger than that exposed without applying stress. TEM shows that the microstructure of under-aged alloy is dominated by - phase mainly and a little θ′ phase. The θ′ and - phases are believed competitive with increasing exposure time. The width of precipitation free zone(PFZ) increases and the granular second phase precipitates at grain-boundary correspondingly. It is shown that the mechanical properties of alloy decrease slightly and present good thermal stability after thermal exposure at 200 ℃ and 220 MPa for 100 h.展开更多
文摘采用Gleeble-3500热模拟试验机对5005铝合金材料进行热压缩试验,应变速率为0.01~10 s^(-1),变形温度为300~500℃,研究了材料的流动应力,并建立了本构方程。研究结果表明:在本实验中,5005铝合金具有负温度敏感性和正应变速率敏感性。变形初期,流动应力随变形程度的增加而迅速升高,达到峰值后,逐渐趋于平缓,此时流变曲线表现为稳态流变特征;该铝合金的热压缩流动应力可用包含Zener-Hollomon参数的双曲正弦关系来描述,其热变形激活能Q为180.69 k J·mol^(-1)。
基金Project(2005CB623705-04) supported by the National Basic Research Program of China
文摘The effect of stress on the microstructure and properties of an Al-Cu-Mg-Ag alloy under-aged at 165 ℃ for 2 h during thermal exposure at 200 ℃ was investigated. The tensile experimental results show that the remained tensile strength of both specimens at room temperature after being exposed at 200 ℃ with and without applying stress rises firstly, and then drops with the increasing of exposure time. The peak value of the remained strength reaches 439 MPa for non-stress-exposure for 10 h, and 454 MPa after being exposed with stress loaded for 20 h at 220 MPa. The elongation change is similar to that of strength. After being exposed for 100 h, specimen exposed at 220 MPa still remains a tensile strength of 401 MPa, larger than that exposed without applying stress. TEM shows that the microstructure of under-aged alloy is dominated by - phase mainly and a little θ′ phase. The θ′ and - phases are believed competitive with increasing exposure time. The width of precipitation free zone(PFZ) increases and the granular second phase precipitates at grain-boundary correspondingly. It is shown that the mechanical properties of alloy decrease slightly and present good thermal stability after thermal exposure at 200 ℃ and 220 MPa for 100 h.
