Selection of powder or wire feedstock material for the laser cladding of Inconel^® 625

The selection of the feedstock material form significantly affects the temperature and resulting distortion generated during laser cladding. An experimental investigation is undertaken to characterize the differences in temperature and deformation histories resulting from laser cladding using powder and wire. While both feedstock produce good quality clads, the powder clad is nearly twice as thick as the wire clad. In situ measurements show that the selection of a powder feedstock results in higher temperatures and greater deformation. However, characterization of the final distortion shows that each clad twists the substrate by nearly the same amount. Thermo-mechanical modeling of the process shows that the disparity in laser absorption efficiency is responsible for the variation in temperature between the powder and wire. Simulations of a multi-layer deposition show that although a single wire layer generates lower temperatures and less deformation than a single powder layer, the wire clad will actually produce greater total deformation because two layers are required to achieve the same thickness as the powder clad.