Effect of processing parameters on titanium nitrided surface layers produced by laser gas nitriding

► Laser surface nitriding was performed using CW CO2 laser. ► Microstructural analysis, microhardness, cracks were performed. ► Laser processing parameters were optimized to produce crack free nitrided layers with high surface hardness. ► Laser surface melting is a suitable technique to nitrided titanium and its alloys. ► Titanium nitride layers were dendritic with different size and morphologies and gradient features.