摘要
在实际生产的过程中,应用电弧增材制造技术对失效模具进行修复时,会在边缘部位出现缺肉、凹陷、过堆积等成形不良的问题,从而导致熔覆层各处厚度不一、起伏较大,对实际的增材制造结果造成精度上的较大误差.为了减少上述缺陷,提出了一种变层厚分层切片算法,主要包括模型前处理、焊接参数的确定、对模型实际切片厚度的修正,并完成最终的增材制造过程.变层厚分层切片算法通过调节熔覆过程中的搭接率从而实现对成形件层厚变化的精准把握,提高成形精度的同时,还可以减少缺肉、凹陷、过堆积等缺陷.通过选取不同的模型对其进行变层厚分层切片以及对应的路径规划,验证了算法的适用性.最后,采用变层厚分层切片算法对棱台结构模型进行处理,并进行熔覆试验.结果表明,理论计算得到的填充路径可以对当前分层面实现完全填充,实际的熔覆高度和平面尺寸与理论计算值相差较小,在热积累较小的时候,成形精度可以达到工业要求.创新点:(1)相对于电弧增材制造技术中传统的等厚分层切片算法,提出了变层厚分层切片算法,能够实现在特定的焊接工艺参数下模型的计算层厚和实际熔覆层厚的相对误差保证在较小范围内.(2)解决了电弧增材制造技术在实际生产中因分层不合理导致的凹陷、过堆积等缺陷,提高了模型的成形精度.
When applying wire arc additive manufacturing technology to repair damaged molds,poor forming problems such as gaps,dents and excessive accumulation may occur at the edges,which lead to the uneven thicknesses in the clading layer and impact the precision of the additive manufactured parts.In order to aovid these defects,a variable thickness layer slicing algorithm is proposed,which mainly consists of model pre-processing,determination of welding parameters,correction of slicing thickness,and completion of the additive manufacturing process.By adjusting the overlap rate during the cladding process,precise control of the thickness variation of the formed part can be achieved,which help to improve the forming precision and decrease the defects as mentioned above.Finally,this variable layer thickness slicing algorithm was used for pyramid structure models,and cladding experiments were conducted.The results showed that the calculated filling path could fully ensure the full filling of the specified layer,and there was little difference in height,length and width between the cladded part and the calculated one.Hence,the forming precision is satisfactory to the industrial requirements on condition that the heat accumulation is low.Highlights:(1)Compared with the traditional equal-thickness slicing algorithm in arc additive manufacturing technology,the proposed algorithm can ensure that under the parameters of a specific welding process,the relative error between the calculated value and the actual value of layer thickness can be kept within a samll range.(2)The application of the variable thickness slicing algorithm can effectively tackle the problems of dents and overstacking caused by unreasonable slicing of layers during the additive manufacturing process,and contributes to the high precison of the additive mold.
作者
刘帅旗
刘仁培
李忠民
杜心伟
沈泳华
LIU Shuaiqi;LIU Renpei;LI Zhongmin;DU Xinwei;SHEN Yonghua(Nanjing University of Aeronautics and Astronautics,Nanjing,210000,China;Tianrun Industrial Technology Co.,Ltd.,Weihai,264413,China)
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2023年第10期120-126,I0009,I0010,共9页
Transactions of The China Welding Institution
关键词
电弧增材制造
变层厚分层切片
成形缺陷
模具修复
wire arc additive manufacturing
variable layer thickness slicing algorithm
forming defect
mold repair
