Laser cladding of turbine blades

A comparative study of two different techniques for the application of wear -resistant coatings for contact surfaces of shroud shelves of gas turbine e ngine blades (GTE) has been conducted. Wear-resistant coatings were applied on In713 by laser cladding with direct injection of the cladding powder in to the melt pool. Laser cladding was conducted with a TRUMPF-2500, CW-CO, l aser. The laser cladding was compared with commercially available plasma cl adding with wire. Both plasma and laser cladded zones were characterized by optical and scanning electron microscopy. It was found that the laser clad ded zone has a higher microhardness value (650-820 HV) compared with that o f the plasma treated material (420-440 HV). This is a result of the signifi cant reduction in grain size in the case of laser cladding. Unlike the plas ma cladded zones, the laser treated material is free of micropores and micr ocracks. (C) 2000 Elsevier Science S.A. All rights reserved.