粉末粒度对纯Re坯显微组织与力学性能的影响

Effect of powder size on microstructure and mechanical properties of rhenium

采用气流分散处理得到两种不同粒度分布的Re粉,利用激光共聚焦显微镜、扫描电子显微镜、维氏硬度计、纳米压痕仪等设备研究粉末粒度和烧结温度对烧结Re坯显微组织及力学性能的影响。结果表明,气流分散处理后的Re粉团聚得到改善,粒度分布范围变窄,平均粒径由21.21μm降至9.45μm。随着温度升高,烧结坯的孔隙数量不断减少。粒度分散后的烧结Re坯显微组织更为均匀,在2320℃下的平均晶粒尺寸由10.8μm降至9.9μm。分散处理后的烧结坯体相对密度提高至98.6%,较未处理的提高了4%,显微硬度提高约12%。分散处理后的烧结坯体有更大的峰值硬度,硬度比未处理的高2~5 GPa。

Two kinds of rhenium powders with the different particle size distribution were prepared by jet dispersion treatment.The effects of the powder particle size and sintering temperature on the microstructure and mechanical properties of the sintered rhenium billet were studied by confocal laser scanning microscope,scanning electron microscope(SEM),Vickers hardness tester,and nano indentor.In the results,the agglomeration of rhenium powders is improved after the jet dispersion treatment,the particle size distribution of rhenium powders is narrowed,and the average particle size decreases from 21.21μm to 9.45μm.With the increase of sintering temperature,the number of pores in the sintered rhenium billet continues to decrease.The microstructure of the sintered rhenium billet after the dispersion treatment shows more uniform,and the average grain size at 2320℃sintering temperature decreases from 10.8μm to 9.9μm.The relative density of the sintered rhenium billet after the dispersion treatment increases to 98.6%,which is 4%higher than untreated,and the microhardness increases by about 12%.The sintered rhenium billet after the dispersion treatment has the greater peak hardness,and the hardness is 2~5 GPa higher than that untreated.