空间变姿态激光堆积变径回转体成形技术研究

Forming Technology Research of Laser Accumulation of Reducing Solid of Revolution with Changing Laserhead Posture

基于激光内送粉技术,借助6轴机器人实现了光头空间变姿态/变方向分层激光堆积成形。重点研究了连续变换基体空间角度对熔道形貌的影响;分析了空间变姿态/变方向激光堆积的难点和关键技术;进行了空间连续变姿态/变方向实体成形试验,并对成形件的壁厚、组织、显微硬度进行了分析。结果表明,随基板倾斜角度增大,熔池最大偏移量为0.06 mm,重力对熔池的流动影响不明显;采用切向分层技术、熔道变角度生长自适应技术以及轴线偏移补偿技术有效地解决了"花瓶"状变径回转体激光成形堆积的难点。成形件与基体为冶金结合,熔道不同区域的组织和显微硬度各有不同,成形组织整体较为细密均匀,区域显微硬度变化较小;成形件大角度变化处,显微硬度有一定下降,成形件小角度变化处,显微硬度无明显改变。

Based on the internal powder feeding technology, laser forming of variable laserhead space posture/direction in the laser accumulation process is realized with 6-axis robot. The effects of continuously variable spatial angle of substrate on the cladding morphology are studied. The difficulties and key technologies of spatial variable posture in laser accumulation process are analyzed. Laser forming experiment of a metal part with continuously varying spatial angle of laserhead is conducted. The formed part microstructure, thickness and microhardness are analyzed. The experimental results show that the offset of cladding layers increase and the max value of offset is0.06 mm. The difficult of space variable posture laser accumulation are solved effectively by tangential layering technology, axis offset compensation technology and cladding layer growth adaptive technology solve. The formed part combines well with the substrate metallurgy. The microstructure of the＂vase＂is dense and uniform relatively,and the overall microhardness value changes small. At large angle changes, the microstructure of formed parts has some porosity and slag, and with a larger microhardness decline. At small angle changes, microhardness has no clear downward.