Nd:YAG laser cladding of Co-Cr-Mo alloy on γ-TiAl substrate

In this work, Co-Cr-Mo powder is used to form laser clads on a γ-TiAl substrate. The single-track geometrical characteristics such as width, height, penetration depth, dilution and wetting angle play the important role to control the characteristics of laser clad coatings formed by overlap of individual tracks. This paper is investigated the relations between the main coaxial laser cladding parameters (laser power P, laser beam scanning speed S and powder feeding rate F) and geometrical characteristics of single tracks by linear regression analysis. The results show that the clad height, H, depends linearly on the FS^-5/4 parameter with the laser power having a minimal effect. Similarly, the cladding width W is controlled by the PS^-2/3 parameter. The penetration depth b and dilution, D are proportional to P²S^-1/4F^-1/4 and P^2/3S^1/2F^-1/2 respectively and wetting angle is controlled by the P^1/4S^1/2F^-1/2 parameter. These empirical dependencies are observed with high values of the correlation coefficient (R>0.9). Finally, based on these relations, a laser cladd processing map was designed to use as a guideline for the selection of proper processing parameters for a required coating.