Superalloys, particularly highly alloyed precipitation hardenable alloys, may exhibit propensity to HAZ cracking, i.e. microfissuring caused by eutectic formation, solidification cracking and base material degradation in the HAZ region during fusion welding. The eutectic formation can be suppressed by laser beam welding process, which involves rapid cooling. Moreover, the ability of this process to join the difficult-to-weld thin section aerospace alloys with minimal component distortion due to low heat input and high reproducibility of joint quality is of prime interest. Although some success has already been reported in laser beam welding of these alloys, there is still a lack of mechanical properties data of these joints. A better understanding of the microstructure-mechanical properties relationship of laser beam welded superalloy joints will promote the application of this joining process in many structural applications including aerospace industry.
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