Abstract:Pure tungsten powder of which the particle size distributed intensively is processed to different samples by selective laser melting(SLM). Then, the samples are preserved in temperature of 1000℃, 1400℃ and 1960℃ for 2h. The mechanical property and microstructure of the samples of different densities and different heat treatment temperatures are studied. The morphology and microstructure are characterized by SEM and XRD respectively. Result shows that the density ratios of the pure tungsten sample vary from 75% to 95%. Bending strength and microhardness increase with the raise of the density, but the microstructure difference between these samples is not obvious. After the heat treatment under different temperature, the mechanical property of the sample by 1400℃ treatment is better than other samples. Under 1960℃ heat treatment, the grain size of pure tungsten sample raises, leading to the decrease of mechanical property. The XRD result demonstrates that the grain structure of the pure tungsten sample does not change after 1960℃ heat treatment.