基于层宽控制的AZ91镁合金TIG电弧增材工艺优化

针对镁合金电弧增材制造表面成形质量控制的难题，通过Design-Expert软件对AZ91镁合金TIG电弧增材的电流、送丝速度、增材速度等工艺参数和熔覆层层宽之间进行建模，探索了各工艺参数对增材层宽的影响规律，并利用增材主要工艺参数和尺寸的数学模型优化了增材电流，根据电流优化值来控制直壁构件层宽。结果表明，对层宽影响最大的是增材电流，其次是增材速度，影响最小的是送丝速度；采用优化后的工艺增材制备的单道多层构件自上至下的层宽波动起伏小，层宽偏差值由4.54 mm减小到0.94 mm，提高了AZ91镁合金增材成形质量。创新点： (1)采用响应面法分析了工艺参数对AZ91镁合金TIG电弧增材层宽的影响规律，建立了二者之间的关系模型。(2)通过优化电流参数实现了AZ91镁合金单道多层增材样件层宽控制，提高了增材样件的成形质量。

Optimization of TIG arc additive process of AZ91 magnesium alloy based on layer width control

In view of the quality control problem of surface forming in magnesium alloy arc additive manufacturing,process parameters of AZ91 magnesium alloy TIG arc additive manufacturing such as current,wire feeding speed and material increasing speed,and the width of cladding layer were modeled by Design-Expert software.The influence of various process parameters on the width of the additive layer was explored.The additive current was optimized by the mathematical model of the main process parameters and dimensions of the additive.Then the layer width of the straight wall component was controlled according to the current optimization value.The results showed that the greatest influence on the layer width was the additive current,followed by the additive speed,and the smallest influence was the wire feed speed.The layer width fluctuations of the single-pass multi-layer component prepared by the optimized process additively were small from top to bottom,and the layer width deviation value was reduced from 4.54 mm to 0.94 mm,which improved the quality of AZ91 magnesium alloy additive forming.