激光熔化沉积Al-Mg-Sc-Zr合金晶粒尺寸预测及成形工艺优化

Grain size prediction and forming process optimization of Al-Mg-Sc-Zr alloy by laser melt deposition

通过激光熔化沉积试验分析了工艺条件(送粉速度、扫描速度和激光功率)对Al-Mg-Sc-Zr合金晶粒尺寸的影响,构建了晶粒尺寸预测模型,优化了成形工艺参数,给出了工艺参数最佳区间。结果表明,相较于激光功率和扫描速度,送粉速度对晶粒尺寸的影响最为显著;随着成形能量密度的增加,合金晶粒尺寸呈现出先减小后增大的演变趋势;采用回归方程构建的晶粒尺寸-工艺参数关系模型能准确预测不同工艺条件下激光熔化沉积Al-Mg-Sc-Zr合金的平均晶粒尺寸,相对误差小于2%;通过响应面分析得到工艺参数最佳区间为:送粉速度2.8~3 g·min^(-1)、激光功率1000~1050 W、扫描速度4~5 mm·s^(-1)。

The influence of process conditions(powder feeding speed,scanning speed and laser power)on the grain size of Al-Mg-Sc-Zr alloy was investigated by laser melt deposition.The grain size prediction model was constructed,and the process parameters were optimized to determine the optimal range of process parameters.The results show that compared with laser power and scanning speed,powder feeding speed has the most significant impact on grain size.An evolution trend of decreasing followed by increasing of grain size was observed with the increase of forming energy density.The process parameters-grain size relationship model constructed by regression equation can accurately predict the average grain size of Al-Mg-Sc-Zr alloy by laser melt deposition under different process conditions,and the relative error is less than 2%.Response surface analysis reveals that the optimum range for process parameters is as follows:powder feeding speed of 2.8-3 g·min^(-1),laser power of 1000-1050 W and scanning speed of 4-5 mm·s^(-1).