【摘要】 采用光纤激光器对8 mm厚TC4钛合金板进行振镜摆动焊接,采用光谱仪和高速摄像机采集等离子体的光谱、图像及小孔的图像,分析摆动焊接抑制小孔型气孔的原因.结果表明,摆动光束对抑制钛合金小孔型焊接气孔具有显著作用;光束未摆动焊接时,焊缝中的气孔率达9.8%;光束摆动后焊缝中的气孔率均降低,其中焊接参数为5 k W,2 m/min,摆动参数为80 Hz,0.5 mm时,小孔形气孔被完全抑制.与光束未摆动相比,光束摆动焊接的小孔稳定性显著增加,其原因是光束摆动提高了光束与熔池液面的接触面积,金属蒸发增强,驱动小孔张开的径向力和轴向力得以增加.更多还原

【Abstract】 TC4 titanium alloy with a thickness of 8mm was welded by fiber laser operating in beam-weaving mode. The plasma spectrum as well as image analysis of plasma and keyhole during the welding process were acquired by spectrometer and high-speed camera respectively. The reason for suppressing keyhole-type porosity in the weld was analyzed. The result showed that the weaving beam had a remarkable effect on the suppression of keyhole porosity in titanium alloy welding. Under the process condition studied in this paper,the porosity presented in the non-weaving beam welded joint was up to 9. 8%,but the porosity in the weaving beam weld was decreased to less than 1%. At the parameter of 5 kW of laser input,2 m/min of scanning speed,80 Hz of oscillation frequency and 0. 5 mm of displacement,the keyhole-type porosity can be completely eliminated.These evidences including the keyhole image,the spectrum intensity and observations of plasma indicated that the weaving beam makes the keyhole more stable compared to the welding with non-weaving beam. It is suggested that the weaving beam may increase the contact area between the laser beam and the molten pool. Therefore,both axial force and radial force making the keyhole open can be increased.更多还原