In order to investigate the effect of die temperature on the microstructure and mechanical properties of formed components, the forming and quenching experiments on U-shaped components of 7075 aluminum alloys at different die temperatures ranging from 25 to 350 °C were carried out. Mechanical properties of formed components were measured by Vickers hardness measurement, tensile test and electrical conductivity test. Microstructure evolution was observed by optical microscopy and scanning electron microscopy. In order to evaluate the effect of die temperature on the shape accuracy of formed components, the springback of U-shaped component was analyzed. The results showed that the Vickers hardness and tensile strength (TS) of formed components decreased with the increase in die temperature. The reduction in strength of the formed component was not obvious until die temperature reached 250 °C. The Vickers hardness and TS were 180 HV and 585 MPa, which were similar to those in T6 temper. When die temperature increased to 350 °C, the Vickers hardness and TS dropped to 93 HV and 445 MPa, respectively. As die temperature increased, the grain size increased gradually and the precipitated phase became larger. Springback angle of formed components decreased with the increase in die temperature. The die temperature should be 200 °C for forming and warm die quenching process of 7075 aluminum alloys to obtain enough strength effect and shape accuracy.

中文翻译：

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AA7075铝合金的成形及热模淬火工艺及其应用

为了研究模具温度对成形零件的组织和力学性能的影响，在70-铝合金的不同模具温度（25-350℃）下对7075铝合金U型零件进行了成形和淬火实验。通过维氏硬度测量，拉伸测试和电导率测试来测量成形部件的机械性能。通过光学显微镜和扫描电子显微镜观察到微观结构的演变。为了评估模具温度对成型零件的形状精度的影响，分析了U形零件的回弹。结果表明，成形模的维氏硬度和拉伸强度（TS）随模具温度的升高而降低。直到模具温度达到250°C时，成型部件的强度降低才明显。维氏硬度和TS分别为180 HV和585 MPa，与T6回火时的相似。当模具温度升至350°C时，维氏硬度和TS分别降至93 HV和445 MPa。随着模头温度的升高，晶粒尺寸逐渐增大，沉淀相变大。成形零件的回弹角随模具温度的升高而减小。模具温度应为200℃，以便对7075铝合金进行成形和热模淬火，以获得足够的强度效果和形状精度。维氏硬度和TS分别降至93 HV和445 MPa。随着模头温度的升高，晶粒尺寸逐渐增大，沉淀相变大。成形零件的回弹角随模具温度的升高而减小。模具温度应为200℃，以便对7075铝合金进行成形和热模淬火，以获得足够的强度效果和形状精度。维氏硬度和TS分别降至93 HV和445 MPa。随着模头温度的升高，晶粒尺寸逐渐增大，沉淀相变大。成形零件的回弹角随模具温度的升高而减小。模具温度应为200℃，以便对7075铝合金进行成形和热模淬火，以获得足够的强度效果和形状精度。