Abstract

A high power continuous wave CO₂ laser has been used to clad the mixture of nickel and aluminum powders (Ni-10 wt% Al) on to cold rolled medium carbon steel. This technique was used to obtain clad layers at laser beam diameter of 5 mm and 1.8 kw laser power. The Specific energy was in the range of 11-240 J/mm².
The present technique includes the continuous feeding of the mixture (9 g/min) into laser melt pool at different traverse speeds (1.5-32 mm/s). The optimum properties with a minimum dilution with substrate were found in the range of 3.9to7.1 mm/s traverse speeds. The heat-affected zone of the substrate under all parameter studies has three morphological distinct zones of pearlite and ferrite. The microstructure of clad layer consists of tow regions, planer region near the substrate and cellular region. The cell size of clad region reduces with increasing traverse speed