化学成分对Al-Mg-Si系铝合金搅拌摩擦增材制造力学性能的影响

Effect of chemical compositions on mechanical properties of Al-Mg-Si series aluminum alloy in friction stir additive manufacturing

采用试验和数值模拟相结合的方法,研究了化学成分对铝合金搅拌摩擦增材制造力学性能的影响。利用Monte Carlo方法模拟了搅拌摩擦增材制造构件的晶粒演变,采用析出相演化模型计算了不同增材层的屈服强度和硬度,通过与试验对比验证了计算模型的有效性。结果显示,在搅拌摩擦增材制造中,不同增材层经历的重搅拌及重加热不同,其作用区域与搅拌针长度相关,且硬度及平均晶粒尺寸也存在一定的差异。通过改变增材方向上不同增材层中Mg和Si元素的化学成分,可以实现增材方向上力学性能的渐变控制。

The method combining test and numerical simulation was used to investigate the effect of chemical compositions on mechanical properties of aluminum alloy after friction stir additive manufacturing(FSAM).Monte Carlo method was used to simulate the grain evolutions of component in FSAM,and the precipitate phase evolution model was used to calculate the yield strength and the hardness of different additive layers.The validity of the calculation model was verified by comparing with the test.The results indicate that the re-stirring and reheating are different for different additive layers in FSAM,whose action areas are related to the pin length,and the hardnesses and average grain sizes are also different.By changing the chemical compositions of Mg and Si in different additive layers on additive direction,the mechanical properties along the additive direction can be gradually controlled.