中文摘要：

为解决采用2.5D切片分层成形时的台阶效应问题,建立了变厚度切片成形几何模型,研究了变送粉量法激光多层熔覆成形对斜坡薄壁件几何形状精度的影响。在单道熔覆范围内,每熔覆2mm长改变一次送粉量,送粉量从0.5g/min近似连续地增大到3.0g/min,获得沿熔覆长度方向、高度从0.05mm近似线性地增大到0.46mm的单道单层熔覆层。用MATLAB仿真斜坡和＂山＂形薄壁件的成形过程,规划出了正确的扫描路径。采用仿真得到的扫描路径,对316L不锈钢粉末进行多层熔覆成形实验验证,成形出了表面较光滑且具有3.37°倾角的斜坡,有效减小了分层成形的台阶效应对斜坡薄壁件几何形状精度的影响。

英文摘要：

To prevent stair-step effect when layered forming parts using 2.5D slices,a geometrical model formed with variable thickness slices was developed.The research work performed with variable powder feed rate.The relationships between the geometrical precision of the parts formed by laser cladding forming（LCF） and the variable powder feed rate were investigated.While change of the powder feed rate every 2mm,the height of the cladding layer increases from 0.05mm to 0.46mm with the powder feed rate varying from 0.5g/min to 3.0g/min.The correct scanning paths were planned by simulating forming process of a ramp and a mountain shape parts through Matlab program.Using the scanning path obtained,a relatively smooth ramp of 316L stainless steel with a slope angle（3.37°） was formed through experiments.The results show the method with variable powder feed rate reduces the stair-step effect significantly and improves the geometrical precision of the ramp thin wall.