【摘要】 以2mm厚LF3铝合金薄板为对象,研究了在平均功率和焊接速度不变时脉冲YAG激光焊脉冲调制参数(脉宽、频率及单脉冲能量)对热导焊缝形状参数(熔深、熔宽及深宽比)的影响规律,并结合脉冲激光焊间断作用的特征,引入"有效峰值功率密度"综合考虑焊接速度、频率、脉宽以及光斑大小对焊缝形状参数的影响。此外,还对脉冲激光焊所形成的特殊的层状焊缝形貌进行研究和分析。结果表明,焊缝形状参数受脉宽及峰值功率密度双重作用的影响。脉冲焊得到的焊缝呈现多层状形貌,层数随频率升高而增多。更多还原

【Abstract】 The effects of pulsing parameters including pulse duration, frequency and energy of single pulse on heat conduction weld shape parameters, which are expressed by penetration depth, bead width and depth-to-width ratio during pulsed Nd:YAG laser welding of 2 mm thick LF3 sheets under constant average power and welding speed, are studied. "Effective Peak Power Density" is introduced with the consideration of discontinuous action of pulsed laser welding to comprehensively study the effects of welding speed, frequency, pulse duration and spot size on weld shape parameters. The specific layered microstructure of pulsing laser weld is also studied. The results show that the weld shape parameters are affected both by pulse duration and peak power density. The welds under pulsed laser welding present layered microstructure, and the number of layers increases as frequency increases.更多还原