Hot cracking sensitivity of 2A14 high strength aluminum alloy in fiber laser welding

摘要

It is a known fact that 2A14 aluminum alloy is susceptible to cracking in the weld metal when welded with fusion processes. Hot cracking sensitivity of 2A14 aluminum alloy in fiber laser welding is first evaluated experimentally. The cracking behaviors of the specimens are evaluated by fishbone cracking test. The fracture morphologies of the weld are observed by optical microscope (OM) and scanning electron microscope (SEM). The results show that the crack formed in fiber laser welding with filler wire of 2A14 aluminum alloy is solidification crack. There is an obvious laser power threshold to form thermal cracks in different welding speeds. Hot cracking tendency is obvious when the laser power is below the threshold. There is no hot cracking when the laser power is greater than or equal to the threshold. The hot cracking rate of the welding speed 3.0m/min is slightly higher than the welding speed 4.5m/min.