Commercially pure Ti powder of 200–325 mesh (43–74 lm) and SiC powder of 400 mesh (38 lm) were used as the cladding materials.
The powders, of different weight ratio of Ti and SiC, was thoroughly mixed in a ball miller for an hour and then mixed with 4 wt.% polyvinyl alcohol (PVA) to form a paste for brush-painting on the specimen.
The painted specimen was then dried in a furnace at 120 C for 1 h.
The dry coating was then ground to a thickness of 0.4 mm by 1000 grade SiC paper in dry condition. The specimen was scanned by a continuous wave multi-mode Nd-YAG laser beam which was focussed by a 100 mm focal length ZnSe lens.
The laser power was varied from 1 to 1.5 kW and the processing speed was varied between 5 and 25 mm/s. The laser spot radius was kept at 1.5 mm.
By overlapping the single tracks at a 50% track-width interval, a large clad surface was produced.
Argon gas blowing through a 4 mm diameter pipe at 20 l/ min was used as shielding gas to molten layer. As Al has the lowest melting point among the constituents in the melt pool, a-Al was the prevent the melt pool from oxidation.