压电驱动GMAW短路过渡行为控制

Piezo-driven short-circuiting metal transfer in GMAW

文中提出了一种基于压电致动器的高动态焊丝启停控制技术,压电致动器膨胀锁止焊丝,收缩则释放焊丝.在焊丝锁止-释放过程中,可以主动驱动熔滴与熔池短路,并利用这一动态过程产生的惯性力驱动短路液桥断裂完成一次熔滴过渡.研究结果表明,组合压电致动器的加入对于小电流下GMAW短路过渡有显著的改善,短路开始和结束都稳定可控,避免了随机短路的发生,不再依赖大短路电流强制缩颈液桥,短路过渡频率显著提升,在DCEP 100 A焊接电流下可达130 Hz,DCEN模式下由于阴极斑点爬升导致电弧稳定性较差,但短路过渡频率也可达100 Hz.

Gas metal arc welding(GMAW)is one of the most commonly used welding process.The strong coupling characteristics of its heat and mass transfer makes it difficult to produce stable droplet transfer under small current.This paper proposes a piezoelectric actuator based high dynamic wire lock-release control process,in which the piezoelectric actuator expands to lock the welding wire,and its contraction releases the wire.During the wire lock-release process,the droplet can be actively driven to short-circuit the molten pool,and the inertial force generated during this dynamic process can be used to actively neck and break the short-circuit liquid bridge.The research results show that the addition of the combined piezoelectric actuator can significantly improve the short-circuit transfer in GMAW under low current,and the start and end of the short-circuit are both stable and controllable,avoiding the occurrence of random short-circuits,and no longer relying on the rapid rising of short-circuit current to force the necking of the liquid bridge.The short-circuit transfer frequency is significantly improved,up to 130 Hz under DCEP 100 A welding current,and up to 100 Hz under DCEN mode.