Laser cladding using scanning optics

Laser cladding using scanning optics is a relatively little studied matter. Scanning optics makes the adjustment of laser beam interaction zone numerically possible and it is, therefore, a more flexible optical tool than the conventional static optics. A series of cladding test were conducted using a 5 kW fiber laser and an oscillating linear scanner with dynamic powder feeding to determine the process characteristics and their possibilities and limitations. This study was carried out using 316L powder as an additive material and S355 mild steel plate as a substrate material. It was noticed that by using scanning optics, it is possible to vary the width and thickness of clad beads on a large scale. With scanning optics, it is possible to affect clad bead geometry so that only a 20% overlapping ratio is used. However, certain cladding parameter combinations expose the clad bead to cladding defects. Also, a fast moving scanned laser beam causes a wave formation to the melt pool which further causes stirring in the melt pool. Another studied matter was the effect of the cladding speed to dilution in laser cladding with scanning optics. The dilution was increased with increase in the cladding speed. However, the increase of the dilution was dependent on the scanning amplitude.