不同沉积路径下钛合金叶片等离子弧增材制造过程的数值模拟  

Numerical simulation of plasma arc additivemanufacturing process of titanium alloy blade under different deposition paths

作　　者：陶瑜杰 韩磊[1] 张浩权 陈希章[1] TAO Yujie;HAN Lei;ZHANG Haoquan;CHEN Xizhang(School of Mechanical and Electrical Engineering,Wenzhou University,Wenzhou 325800,Zhejiang,China)

机构地区：[1]温州大学机电工程学院,浙江温州325800

出　　处：《材料工程》2023年第10期156-164,共9页Journal of Materials Engineering

基　　金：浙江省重点研发计划(2021C04022)。

摘　　要：等离子弧直接沉积技术因热输入集中,材料易产生较大的残余应力,发生不均匀形变,极大影响成型零件的质量。采用生死单元技术、瞬态热模型和热弹塑性模型对增材制造过程中的热过程和残余应力进行数值模拟计算,研究不同沉积路径对等离子弧增材制造中TC4叶片热循环特性和残余应力分布规律的影响。同时通过热实验验证了模型的有效性,模拟的热曲线与实验结果吻合。结果表明,等离子弧直接沉积截面为“月牙”形的叶片零件,两种路径在沉积层与基板的连接区域都会产生较之其余区域更高的残余应力,轮廓偏移路径有较之全光栅式路径更好的散热情况,轮廓偏移路径沉积层的残余应力明显低于全光栅式路径。多层零件的新层开始沉积时,先前沉积层会经历复杂的热循环,峰值温度由底层向中间层逐渐升高。随着新层不断地沉积在顶部,零件瞬态应力分布进行着规律的变化,较大应力位于接近顶层中部区域和底部与基板相接区域,然后保持并逐渐转化为零件内的残余应力。Due to the concentration of heat input in the plasma arc direct deposition technology,the material was prone to large residual stress and uneven deformation,which greatly affects the quality of the formed parts.All of the birth-death cell technique,the transient thermal model and the thermo-elasto-plastic model were adopted for the thermal process and residual stress simulation during the additive manufacturing process.The calculation results were used to study the effects of different deposition paths on the thermal cycle characteristics and residual stress distribution of TC4 part in plasma arc additive manufacturing.Meanwhile,the validation experiment was carried out to check the effectiveness of the finite element model through thermal tests.The simulated thermal curves match the experimental results well.The results show that both paths generate higher residual stress in the area around the arc-extinguishing point than the rest,and the zigzag with contour-offset path has better heat dissipation than the full zigzag path,and the residual stress of the deposited layer of the contour-offset path is significantly lower than that of the full raster path.Previous layers are subjected to a complicated thermal cycles,when the new layers are deposited on old layers.The peak temperature is increased from the bottom layer to the middle layer.As new layer is deposited on top,the transient stress distribution of parts changes regularly.Larger stress is located near the middle of the top layers and the area where the bottom meets the substrate,which is then maintained and gradually converted into residual stress within the part.

关 键 词：增材制造 TC4 飞机叶片 热历史 残余应力 数值模拟 

分 类 号：TG146.23[一般工业技术—材料科学与工程]