晶粒尺寸与钨铜合金相关性的研究  

Relativity between Grain Size and Tungsten Copper Alloy

作　　者：高红梅[1] 陈文革[1] 连凯 张飞奇 

机构地区：[1]西安理工大学材料科学与工程学院

出　　处：《稀有金属》2018年第1期59-66,共8页Chinese Journal of Rare Metals

基　　金：陕西省重点研发项目(2017ZDXM-GY-050);西安市科技支撑项目(CXY1342(2));国家自然科学基金重点项目(50834003)资助

摘　　要：采用不同粒度钨粉和循环热处理分别制备出不同晶粒尺寸的CuW70合金。利用光学显微镜（OM）、扫描电子显微镜（SEM）和拉压万能试验机研究合金的组织结构和性能，结果表明：采用粒径分别是80nm，6～8μm和30～35μm的钨粉，经混料成型和熔渗烧结可以制备出晶粒尺寸分别为0．52，5．18和20．69μm的钨铜合金；1300℃多次烧结或热处理可以改变钨铜合金的晶粒尺寸，其规律是随热处理次数的增加晶粒尺寸先减小后增大，但变化幅度不大。室温下，钨铜合金硬度、抗压强度和相对密度随晶粒尺寸的增大而减小，电导率则随晶粒尺寸的增大而升高，当晶粒尺寸由0．52μm变为20．69μm时，硬度、抗压强度、相对密度、电导率分别从HB202，1232．17MPa，99．2％，42．8％IACS变化为HB179。1116．31MPa，97．5％，44．6％IACS；而高温下，粗晶粒钨铜合金表现出良好的抗蠕变性能，随晶粒尺寸的减小合金的蠕变寿命变短，晶粒尺寸由0．52μm变为20．69pm时，合金蠕变寿命由26．3h持续到87．2h。细晶钨铜合金相对于粗晶的首击穿烧蚀面积女．击穿坑名而浅．100次电击穿后．表面均有铜的飞溅沉积，出现大量的孔洞和裸露的钨骨架，晶粒越粗该现象越明显。CuW70 alloy with different grain sizes was prepared by tungsten powder with different sizes and cyclic heat treatment. The structure and properties of alloy were studied by optical microscopy （OM） , scanning electron microscopy （SEM） , tension and com- pression testing machine. The results showed that tungsten powder of which particle sizes were 80 nm, 6 -8 μm and 30 -35 μm, after mixing molding and infiltration sintering, could be used to produce tungsten-copper alloy, of which grain sizes were 0.52 μm, 5.18 μm and 20.69 μm, respectively. Grain size of tungsten-copper alloy could be changed under repeatedly sintering or heat treatment at 1300 ℃, and the law was that the grain size of the alloy decreased and then increased with the increase of the number of heat treat- ment, but the change was limited. At room temperature, with grain size increasing, the hardness, compressive strength and relative density of tungsten copper alloy decreased, the conductivity increased with the grain size increasing, when the grain size increased from 0.52 to 20.69 μm, the hardness, compressive strength, relative density and electrical conductivity changed from HB 202, 1232.17 MPa, 99.2% , 42.8% IACS to HB 179, 1116.31 MPa, 97.5% , 44.6% IACS, respectively. However, the high temperature, coarse- grained tungsten-copper alloy exhibited good creep resistance, and with decreasing of grain size, the creep life of alloy decreased ; when the grain sizes became from 0.52 to 20.69 μm, the creep life of alloy changed from 26.3 to 87.2 h. Compared to the coarse grained tungsten-copper, the first breakdown area of fine-grained tungsten-copper alloy were larger, and the breakdown pit was more and shallo- wer than that of coarse grain, After 100 times ablation, each sample surface had copper spatter and deposition, and a large number of holes and exposed tunzsten skeleton were produced. Furthermore. the coarser ~rains. the more obvious the nhenomenon was.

关 键 词：钨铜合金 晶粒尺寸 组织性能 循环热处理 电弧烧蚀 

分 类 号：TF124[冶金工程—粉末冶金]