Abstract：Indirect measurement is conducted with a reflectivity measurement device to determine the laser light
absorptivity of the commonly used metal powders and metals bulks in laser additive manufacturing technique. The effects
of the size and the shape of metal powders on the laser light absorptivity are investigated, and the laser light absorptivity
of metal powders and metal bulks to 1064nm laser light and 532nm laser light is measured respectively. The measurement
results show that powders with better sphericity and bigger particle sizes exhibit higher laser light absorptivity, and the laser
light absorptivity of metal powders and metal bulks to the 532nm laser light is greater than to the 1064nm laser light. The
measurement results can provide basic experimental data for the laser additive manufacturing of these metals.
2017, 
