中文摘要：

为了提高搭接熔覆层的质量并控制搭接结合界面,研究了工艺参数对横向搭接结合区域组织形态的影响。结果显示,当扫描速度、送粉速率、激光功率分别在100250 mm/min,67.5 g/min,1 5002 500 W区间变化时,搭接结合区域呈现出不同的界面组织形态,没有出现白亮层。这些界面组织一类表现为具有组织与方向＂遗传性＂的连续外延式生长,另一类表现为非连续外延生长。工艺参数对结合界面组织的影响与其对前一道熔覆层表面转向枝晶区域的重熔深度以及前一道表面晶粒取向、各晶粒的熔化程度和激光熔池内存在的对流作用有关。

英文摘要：

In order to improve the cladding quality and to control the bonding interface of the layer formed by overlapping laser cladding,the effects of parameters on the microstructure of bonding interface were studied.The results show that when scanning speed,powder feeding rate and laser power change in the range of 100-250 mm/min,6-7.5 g/min and 1 500-2 500 W,respectively,the bonding region does not appear a white layer and presents different morphologies.One of morphologies is the continuous epitaxial growth with inherited microstructures and directions,and the other is discontinuous epitaxial growth.This is related to the effects of parameters on the depth of remelting region of a shifted dendrite,the orientation and molten degree of grain of a prior layer surface,and the con-vection in the molten pool.