铝合金1100 H14的激光焊接工艺研究

受加工工艺、热变形以及铝合金对激光的强烈反射等因素影响,铝合金的激光焊接存在较大的困难。以1.0mm厚1100H14铝合金薄板为对象,采用Nd:YAG脉冲激光器进行焊接,重点研究了激光焊接过程中脉冲波形、激光功率、脉冲频率、焊接速度等对焊接成形质量的影响。焊后进行拉伸强度测试、金相观察、显微硬度测定、断口分析。实验结果表明:预热保温的焊接波形焊接试样优于梯形波焊接试样:优化的焊接参数为峰值功率8kW,单脉冲能量20J,频率10Hz,焊接速度2.1mm/s;抗拉强度为95.7N/mm~2,达到母材抗拉强度的86%;焊缝中部为等轴细晶,熔合线附近是柱状晶组织。焊缝区有软化现象,硬度为HV4.9 33.2,达到母材的77%。

Research on the Welding of 1100 H14 Aluminum Alloy by Laser Technology

Due to the processing, thermal deformation and strong reflection of aluminum for lasers and other factors, there are huge difficulties of laser welding of aluminum. This work chose 1100 H14 aluminum alloy sheet with 1.0mm thick for experiments by a pulsed Nd:YAG laser, and the research focus on the pulse waveforms, laser power, laser frequency and welding speed influence on the property of the joint. After welding, tensile test, microstructure analysis, hardness test and fracture analysis were carried out on the welded joint. The results show that welded specimens with preheat and insulation wave are better than the ones with trapezoidal wave; laser welding parameters have been optimized for the peak power of 8 kW, single pulse energy of 20 J, frequency of 10 Hz, scanning speed of 2.1 mm/s. Tensile strength of the specimen optimized parameter is 95.7 N/mm2, up to 86% of base material tensile strength; the central part of the joint is equiaxed grains, and near the fusion line is the columnar grains. The welded joint has the phenomenon of softening, the hardness of welded joints is HV4.9 33.2,up to 77% of base material hardness.