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ZL10 8表面镍基粉末激光合金化的实验研究表明 :激光合金化层的显微组织由两部分组成 ,与基体金属交界处是垂直于熔合线生长的具有定向凝固特征的树枝状晶 ,合金化区是细小的等轴状晶。在树枝状晶相邻间的凹陷处和基体金属未熔化晶粒的界面上最有可能产生气泡核 ,熔池保护不良 ,合金粉末或粘接剂中残存水分 ,均是影响气泡生成的主要因素。对于合金层中的裂纹 ,主要是在熔池凝固末期 ,已凝固合金化层金属塑性不足并在残余拉应力作用下造成的低塑性脆化裂纹。
ZL10 8 surface nickel-based powder laser alloying experimental results show that: the laser alloying layer microstructure consists of two parts, and the junction of the base metal is perpendicular to the growth of fusion lines with directional solidification characteristics of dendrites, alloying Area is a small equiaxed crystal. Bubble nuclei are most likely to occur at the interface between the dendrite adjacent to the dendrites and the unmelted grains of the base metal, and poor protection of the melt pool and residual moisture in the alloy powder or adhesive are the main factors affecting bubble generation . For the cracks in the alloy layer, mainly in the end of the pool solidification, solidified alloy layer metal plasticity and under the residual tensile stress caused by low plasticity brittle crack.