Laser surface treatment of pre-prepared Rene 41 surface

Laser controlled melting of pre-prepared Rene 41 surface is carried out. A carbon film composing of uniformly distributed 5% TiC carbide particles is formed at the surface prior to laser treatment process. The carbon film provides increased absorption of the incident radiation and facilitates embedding of TiC particles at the surface region of the workpiece during the treatment process. Nitrogen at high pressure is used as assisting gas during the controlled melting. It is found that laser treated layer extents 40 μm below the surface with almost uniform thickness. Fine grains and ultra-short dendrites are formed at the surface region of the laser treated layer. Partially dissolved TiC particles and γ, γ′ and γ′N phases are observed in the treated layer.