MICROSTRUCTURE AND PROPERTIES OF LASER REMELTED CHROMIUM CARBIDE LAYER

This study evaluated the feasibility of laser consolidation for improv ing the properties of the plasma-coated layer. Furthermore, the mechan ism of the degradation sequence of the chrome carbide layer applied on the turbine blades was postulated. The laser consolidation could be s uccessfully applied for improving the surface properties of the plasma -coated blade if the proper conditions were carefully chosen. The cons olidated layer had erosion and corrosion resistance and a bond strengt h superior to those of the as-plasma-coated layer. The properties of t he consolidated layer were strongly dependent upon the degree of dilut ion, especially on the Fe pick-up from the substrate. The degradation of the plasma coating layer was thought to be a result of the repeatin g action of the solid particle erosion, corrosion penetration through the pores and oxide films formed along the interlayer surface and impa ct spalling. (C) 1998 Elsevier Science S.A.