电子束熔炼制备块体钨的组织与显微硬度研究  

Study on microstructure and microhardness of bulk tungsten prepared by electron beam melting

作　　者：孙满意 赵龙海 石爽[1,2] 谭毅 SUN Manyi;ZHAO Longhai;SHI Shuang;TAN Yi(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China;Engineering Laboratory for New Energy Material Energetice Beam Metallurgy Equipment of Liaoning Province,Dalian 116024,China)

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116024 [2]辽宁省新能源材料载能束冶金装备工程实验室,辽宁大连116024

出　　处：《材料科学与工艺》2020年第6期8-14,共7页Materials Science and Technology

基　　金：国家自然科学基金资助项目(91860123).

摘　　要：钨材料具有极高的熔点,传统上采用粉末冶金方法制备,获得的钨材料具有晶粒细小、微观组织均匀等优点,但致密性不足。为进一步提升钨材料的性能,本研究将98.3%的钨粉和1.7%的碳粉均匀混合,在1 800℃、26 MPa条件下热压成型,而后采用电子束熔炼技术对成型后的钨块进行熔炼,利用金相显微镜、SEM、显微硬度计等对其显微组织、致密度和显微硬度进行评价,并与传统粉末冶金法制备的块体钨的性能进行了对比。结果表明:电子束熔炼制备的钨锭冶金质量好,致密度可达99.8%;试样的显微硬度达到9.16 GPa,显著高于粉末冶金法制备的块体钨材料,突破了热压烧结工艺制备块体钨的致密度-显微硬度的关系;经1 300℃、6 h退火热处理后,显微硬度略有下降,但仍达到8.86 GPa,显示出电子束熔炼技术在制备块体钨硬度性能方面的优势。Due to high melting point, the traditional preparation method of tungsten is powder metallurgy(PM). The prepared tungsten material has fine and uniform microstructure, but the density is not high enough. Low density of tungsten prepared by traditional powder metallurgy is a technical bottleneck that is difficult to break through, and thus deteriorates the performance of tungsten. There is an urgent need to develop new preparation techniques. In this study, 98.3% of tungsten powder and 1.7% of carbon powder were uniformly mixed, then hot pressed at 1 800 ℃ and 26 MPa, and then smelted by electron beam melting technology. Its microstructure, density, and microhardness were evaluated by optical microscope, scanning electron microscope(SEM), and microhardness tester and compared with the performance of bulk tungsten prepared by traditional powder metallurgy. The results show that the tungsten ingot prepared by electron beam melting has excellent metallurgical quality, and the relative density can reach 99.8%. The microhardness value of the bulk tungsten reaches 9.16 GPa, which is significantly higher than that prepared by powder metallurgy, and breaks through the relationship between the density-microhardness of bulk tungsten prepared by traditional processes. After annealing heat treatment at 1 300 ℃ for 6 h, the microhardness decreased slightly and still had 8.86 GPa, showing the hardness performance advantages of electron beam melting in the preparation of bulk tungsten.

关 键 词：电子束熔炼 块体钨 显微组织 致密度 显微硬度 

分 类 号：TF134[冶金工程—冶金物理化学]