镁合金摆动多道增材层成形特征参数与尺寸控制规律研究  

Forming Characteristic Parameters and Dimension Control Principle on Weaving Multi-pass Additive Layer of Magnesium Alloy

作　　者：罗晓宇 冯曰海[1] 赵鑫 刘思余 LUO Xiaoyu;FENG Yuehai;ZHAO Xin;LIU Siyu(School of Material Science and Engineering,Nanjing University of Science&Technology,Nanjing 210094,China;Shanghai Aerospace Precision Machinery Institute,Shanghai 201600,China)

机构地区：[1]南京理工大学材料科学与工程学院,南京210094 [2]上海航天精密机械研究所,上海201600

出　　处：《材料导报》2023年第18期186-192,共7页Materials Reports

基　　金：国防创新特区项目(17-H863)。

摘　　要：针对AZ31B镁合金多道增材成形中尺寸精确控制的问题,定义了表面平整度、波峰平均高度差和波峰平均高度来表征摆动钨极氩弧多道增材层的成形特征,采用响应曲面法建立了摆动参数与多道增材层成形特征参数之间的回归模型,分析了摆动参数对成形特征参数的影响规律,并对通过模型优化得到的摆动参数进行了实际验证。建模与实验结果发现:表面平整度在摆动参数交互作用的影响下呈现先增大后减小的变化趋势;当偏移量大于11 mm时,摆动幅度小于3 mm、停留时间小于0.3 s和行进速度大于30 cm/min都能使波峰平均高度差趋于最小;波峰平均高度受停留时间和偏移量的影响最显著。回归模型优化获得的最佳摆动参数为:摆动幅度2.56 mm、摆动频率2.5 Hz、停留时间0.3 s、行进速度30 cm/min和偏移量11.46 mm。采用该参数获得的多道增材层各成形特征参数分别为:表面平整度0.98,波峰平均高度差为0.03 mm仅占波峰平均高度的1.07%,波峰平均高度为(2.80±0.02)mm与目标值间的误差仅为0.71%,多道增材层的成形得到优化。As the problem of low dimensional control accuracy in the multi-pass additive of AZ31B magnesium alloy,the surface flatness,the average height difference of the wave crests and the average height of the wave crests were defined to characterize the forming characteristics of the multi-pass additive layer.The regression models between the weaving parameters and the forming characteristic parameters were established by the response surface method.The effect of the weaving parameters on the forming characteristic parameters was analyzed,and the weaving parameters obtained through model were verified in practice.The results show that the surface flatness first increases and then decreases under the influence of the interactions.When the offset is larger than 11 mm,setting the weaving amplitude less than 3 mm or the residence time less than 0.3 s or the travel speed faster than 30 cm/min can make the average height difference of the wave crests tend to be the smallest.The average height of the wave crests is mainly affected by the residence time and the offset.The better weaving parameters obtained from the optimized models are the weaving amplitude of 2.56 mm,the weaving frequency of 2.5 Hz,the residence time of 0.3 s,the travel speed of 30 cm/min and the offset of 11.46 mm.The results of the verification experiment show that the surface flatness is 0.98.The average height difference of the wave crests is 0.03 mm,which accounts for 1.07%of the average height of the wave crests.The average height of the wave crests is(2.80±0.02)mm,the error between the target value is only 0.71%.The forming of the multi-pass additive layer has been optimized.

关 键 词：镁合金 钨极氩弧焊 响应曲面法 成形特征 电弧增材制造 

分 类 号：TG444.74[金属学及工艺—焊接]