Underwater Laser Welding of Pure Ti: Oxidation and Hardening Behaviors

The local dry underwater laser welding of cp-Ti, with air as an assisting gas, and in a simulated facility was researched, aiming to find viable economical method for repairing titanium alloy vehicles situ the future. Macro-morphology, microstructure, microhardness cp-Ti welds, function parameters, were experimentally characterized. oxidation hardening behaviors welds also studied detail. It found that assisted blowing is feasible obtaining complete glossy weld. Compared weld atmosphere, cross-section morphology almost unaffected by special environment. presented three-layer structure. High temperature high pressure water vapor are direct causes oxidation, porosity defects further aggravate behavior. oxygen-enriched areas mostly concentrated top area center near fusion zone, because higher number grain boundaries phase boundaries. In addition, partial caused strength acicular martensite rapid cooling effect water, will lead hardening. However, adjusting process such increasing speed, can effectively reduce Our findings provide understanding influence environment on welding, verify feasibility more repair large facilities.