Surface Cracking of Laser Melted Ti-6Al-4V Alloy

The characteristic features of surface cracking observed after laser melting with CO₂ and Nd:YAG laser were described. The cracks were always present, their length approaching some part of melted zone and scarcely dependent on laser melting conditions. The appearance of cracks was attributed mainly to martensitic transformation within the surface layer. The possible contribution of developed thermal stresses cannot be also excluded. The existence of cracks may be utilized for the enhancement of bone - implant strength.