Selective laser sintering of gas atomized M2 high speed steel powder

Selective laser sintering of the gas atomized M2 high speed steel powder was performed using laser powers of 2.5-100 W, scan rates of 1-30 mm/s and scan line spacings of 0.15-0.75 mm. With increasing laser power, the sintered surface varied from open/closed pores to a fully dense structure. Large lateral pores were found in the sintered surface of samples using high scan rates. For fully dense samples, smooth surfaces could be achieved using large scan line spacing. The as-supplied and sieved M2 powder particles with size ranging from 0.04 to 400 mu m and 53 to 150 mu m, respectively, were found to give better laser sinterability as compared with those powder particles with finer (< 38 mu m) or coarser (> 150 mu m) sizes. (C) 2000 Kluwer Academic Publishers.