SiCp/Mg复合材料激光焊规范参数对焊缝强度的影响及其数学模型的建立

对于焊接性较差的碳化硅颗粒增强镁基（SiCp／Mg）复合材料，采用高能激光束进行了焊接．通过选择合适的激光焊工艺参数，可焊成外观成形及性能均良好的焊接接头．激光焊的输出功率（P）、焊接违反（v）、脉冲频率（f）、脉冲宽度（w）对接头强度都有影响，其中尤以激光输出功率与焊接速度的比值，即焊接线能量P/v的影响最大．对于厚度为1mm的对接缝，试验所得最佳工艺参数为：P=170Wv=7.5mm/s,f=30Hz,w=5ms.焊接时使用氢气（Ar）进行保护．所得拉伸强度值为104．3MPa，达到了母材的52％．另外，本文还应用多项式回归法建立了焊接接头拉伸强度与工艺参数关系的数学模型．

Effect of Laser Welding Parameters of SiC Particle Reinforced Magnesium Matrix Composite on Weld Strength and Establishment of Mathematics Model

Laser beam was used to weld SiCp/Mg composite and weld joints with fine outershape and properties was acquired by using suitable laser welding parameters. The output power(P), welding speed (v), pulse frequency (f) and pulse width (w) of laser beam all had effects onthe strength of welded joint. Comparatively, the ratio of output power to welding speed-weldinglinear energy P/v was the most important factor. And there was a optimal P/v to make thestrength of weld joint highest. For the specimen with the thickness of 1mm, the optimalparameters are: P= 170W, v = 7.5mm/s, f=30Hz, w = 5ms. Ar was used as protective gas. Underthis condition, the value of the tensile strength was 104.3MPa that was equal to the 52 percentof that of the base metal.Moreover, the method of polynomial regression was used to establish the mathematicalmodel of relation between P/v and tensile strength of welded joint.