送粉角度对激光熔覆铁基复合涂层形状特征的影响

通过分析激光熔覆过程中光束、粉末和熔池间的作用机理，建立了送粉式激光熔覆材料有效利用率的数学模型，在此基础上推导了送粉角度与工艺参数之间的定量关系式，并计算了不同送粉角度下的熔覆材料有效利用率、熔高和横截面积。结果表明，在熔覆工艺参数不变的条件下，理论计算的熔覆材料有效利用率、熔覆层高度和横截面积均随送粉角度的增加而增大，且均高于实验检测值。激光熔覆过程中，由于粉末烧损和机械损失，使熔覆材料有效利用率、熔高和横截面积随送粉角度变化出现最大值，理想送粉角度为60。

Influence of powder feeding angle on geometric parameters of laser-clad Fe-based composite coating

According to the reaction mechanism of laser beam, powder particles and melting pool during the laser cladding process, a mathematical model of powder utilization efficiency was formulated. A quantitive expression describing the relation between the powder injection angle and the contour parameters of laser cladding coating was obtained. Based on thermo-physical properties of Fe55 alloy powder and laser cladding process parameters, the powder utilization efficiency, cladding coating height and cross-section area were calculated by means of AutoCAD software. The results show that the powder utilization efficiency, and cladding coating height and cross-section area increase with the powder injection angle increasing, and theoretically calculated values are larger than the experimental values. Owing to powder burning and mechanical losing in the process of laser cladding, the powder utilization efficiency, and cladding coating height and cross-section area reach their maxima simultaneously with the variation of powder injection angle. The ideal powder injection angle is 60°.