选择性激光熔化制备纯钨的性能研究

Properties of Pure Tungsten Produced by Selective Laser Melting

以粒度集中的纯钨粉末为原料,通过选择性激光熔化技术(selective laser melting, SLM)制备样品,分别经过1000, 1400及1960℃的热处理2 h。研究不同相对密度和不同热处理后样品的力学性能和显微组织,并采用X射线衍射(XRD)表征其微观结构。结果表明:纯钨样品的相对密度处于75%~95%之间,其抗弯强度和显微硬度随相对密度的增加而增大,显微组织大体相似。经不同高温处理后,在1400℃处理后样品达到了最佳的力学性能,1960℃处理后样品的晶粒发生了明显的长大现象,材料力学性能降低。XRD图谱结果表明,SLM制得样品及经过1960℃烧结后,其晶体结构并未发生改变。

Pure tungsten powder with intensively distributed particle size was processed to different samples by selective laser melting (SLM).Then,the samples were heat-treated at temperatures of 1000 ℃,1400 ℃ and 1960 ℃ for 2 h.The mechanical property and microstructure of the samples with different densities and different heat treatment temperatures were studied.The morphology and microstructure were characterized by SEM and XRD,respectively.Results show that the density ratios of the pure tungsten sample vary from 75% to 95%.Bending strength and microhardness increase with the rise of the density,but the microstructure difference between these samples is not obvious.After the heat treatment at different temperatures,the mechanical property of the sample after 1400 ℃ treatment is better than those of other samples.Under 1960 ℃ heat treatment,the grain size of pure tungsten sample rises,thus 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.