7075铝合金的等温自由锻造温度优化

Optimization on isothermal open-die forging temperature for aluminum alloy 7075

为优化7075铝合金的性能,采用不同的锻造温度进行了7075铝合金等温自由锻造试验,并研究了锻造温度对7075铝合金的拉伸性能、冲击性能和耐磨损性能的影响。试验结果表明：锻造温度过低,7075铝合金内部很难动态再结晶,晶粒粗大,组织不均匀,不利于合金拉伸、冲击和耐磨损性能的提高;随着锻造温度的上升,7075铝合金内部的动态再结晶加强,晶粒逐渐变小、细化,组织分布也逐步均匀,合金的拉伸、冲击和耐磨损性能得到提高;当锻造温度达到420℃时,动态再结晶达到最强化,7075铝合金内部晶粒几乎都得到细化,且大小均匀,组织得到最大程度改善,合金的拉伸、冲击和耐磨损性能得到极大改善;当温度超过420℃时,随着温度进一步上升,7075铝合金的晶粒不再发生动态再结晶,晶粒不再细化,反而呈现出变粗大的迹象,组织不再均匀、致密,合金的拉伸、冲击和耐磨损性能呈现下降趋势。因此,7075铝合金的锻造温度优选为420℃。

In order to optimize the performance of aluminum alloy 7075,the isothermal open-die forging test of aluminum alloy 7075 was implemented under different forging temperatures,and the influences of forging temperature on tensile property,impact property and wear resistance were analyzed. The experimental results show that when the forging temperature is too low,the dynamic recrystallization hardly occurs inside aluminum alloy 7075,and the existed uneven microstructure with large grain size is not conducive to the improvement of tensile property and impact property as well as wear resistance. However,with the increase of forging temperature,the dynamic recrystallization inside aluminum alloy 7075 is improved,the grain size is smaller and refined to realize uniform distribution,and the tensile property and impact property as well as wear resistance are improved. When the forging temperature reaches 420 ℃,the dynamic recrystallization is up to the strongest,the alloy grains are almost completely refined with uniform distribution,the microstructure is improved to the maximum extent,and the tensile property and impact property as well as wear resistance are improved greatly. Furthermore,when the temperature exceeds 420 ℃,the dynamic recrystallization of aluminum alloy 7075 no longer occurs,the grain is no longer refined and becomes coarse,and the microstructure becomes uneven and no compact,which leads to the decrease trend of tensile property,impact property and wear resistance. So,the optimized forging temperature of aluminum alloy 7075 is 420 ℃.