摘要
研究了为满足特定图案要求在超薄板材 ( 0 1～ 0 15mm)上进行Nd :YAG脉冲激光送粉精细熔覆过程中激光熔覆特性、侧向和同轴喷嘴送粉熔覆、基体的真空吸附夹紧和强迫制冷、熔覆层几何形貌、元素分布和微观组织特性等因素。得到了熔覆层高宽比为 0 88和 0 5。
Nd:YAG pulsed laser cladding with powder feeding was investigated to achieve laser clad with specific pattern and roughness on very thin metal sheets (0 1～0 15mm) to meet industrial requirements. Characterization of pulsed laser cladding on thin sheet substrate, side nozzle, coaxial nozzle, high speed video visualization of powder flow for both nozzles, microstructure evolution, vacuum clamping, chiller cooling were presented. Sound laser clad pattern with height/width ration 0 88 or 0 50 and identical quality was obtained. Laser cladding on thin sheet is rather sensitive to parameters due to the melt pool unstability and sheet distortion. Burn through, un\|continuity and less clad at the start are the main shortcomings. Vacuum clamping and cooling can improve the process sensitivity. Laser cladding on thin sheet characterizes element deviation and equiaxial crystals on microstructure, which is different from the normal bulk substrate cladding.
关键词
脉冲Nd:YAG激光熔覆
送粉熔覆
超薄板基体
pulsed Nd:YAG laser cladding
side nozzle and coaxial nozzle powder feeding
ultra thin sheet substrate
