Laser welding in the manufacture of superalloy components

Summary

This paper describes the welding of superalloys using high-power CO₂ and Nd:YAG lasers, to be applied to the manufacture of aeroengine and power plant components. The rapidly solidified microstructures in the fusion zone and the microfissures in the heat-affected zone (HAZ) have been investigated using scanning and transmission electron microscopes (SEM, TEM).

With Inconel 718 superalloy, microfissure-free welds were achieved in the annealed state with grain sizes of ASTM 10 or finer. Laser-welded aeroengine components made of rolled and cast Inconel 718 are presented. The characteristics of joints obtained were also assessed via fatigue tests at high temperature.

Laser cutting combined with laser welding techniques are applied to demonstrate that the manufacture of welded structures can be simplified with minimum deformation, thereby reducing costs.