变形量对旋转锻造钨合金组织及绝热剪切敏感性影响  

Influence of Deformation Ratio on Microstructure and Adiabatic Shear Banding in Tungsten Heavy Alloy Processed by Rotary Swaging

作　　者：彭磊[1] 李树奎[1] 才鸿年[1] 周晓青[1] 

机构地区：[1]北京理工大学材料科学与工程学院,北京100081

出　　处：《稀有金属》2011年第2期218-222,共5页Chinese Journal of Rare Metals

基　　金：国家部委预研项目(054060855)资助

摘　　要：对烧结态93W-4.9Ni-2.1Fe合金进行不同变形量旋转锻造,研究变形量对钨合金微观组织及绝热剪切敏感性的影响。微观组织观察结果表明,旋转锻造形变后钨颗粒沿变形方向被拉长为椭球形,随变形量由3.45%增加至42.11%,钨颗粒变形程度加剧,长径比由1.32增加至2.41;位于钨颗粒间的粘结相则沿变形方向逐渐拉长为细长的条状组织。对不同变形量的旋转锻造钨合金,沿棒料径向取样进行动态压缩试验后发现:当变形量增加至15.84%(钨颗粒长径比1.47)时,旋转锻造钨合金塑性变形方式发生改变,合金中开始出现绝热剪切现象;此后,随旋转锻造变形量(钨颗粒长径比)的增加,旋转锻造钨合金中绝热剪切带宽度减小,合金绝热剪切敏感性增大。随旋转锻造变形量(钨颗粒长径比)的增大,合金应变硬化能力减小,同时动态加载时绝热温升数值增大,软化效应增强,这是旋转锻造钨合金绝热剪切敏感性随变形量(钨颗粒长径比)增加而增大的主要原因。The as-sintered 93W-4.9Ni-2.1Fe alloy was processed by rotary swaging with various deformation ratios.The effect of deformation ratio on the microstructure and adiabatic shear localization were investigated.The microstructure examination showed that the tungsten particles were elongated along the deformation direction in the rotary swaged tungsten heavy alloys（WHAs） and the aspect ratio of tungsten particles increased from 1.32 to 2.41 with the deformation ratio rising from 3.45% to 42.11%.At the same time,the matrix between tungsten particles was elongated to be strip gradually with the increasing deformation ratio.The dynamic compression result of radial specimens revealed that when the deformation ratio got to 15.84%（aspect ratio of tungsten particles was 1.47）,the plastic deformation mode changed and adiabatic shear banding began to occur in rotary swaged WHAs.With the rising deformation ratio（or aspect ratio of tungsten particles） in swaged WHAs,the width of adiabatic shear banding reduced and the sensitivity to adiabatic shear banding of radial specimen increased.Moreover,with the increase in deformation ratio,the strain hardening capability of the alloys reduced,and the adiabatic temperature rose during dynamic compression increased which led to the more apparent softening effect.These were the main reasons why the sensitivity of the rotary swaged WHAs to adiabatic shear banding increased with the rising deformation ratio.

关 键 词：旋转锻造 钨合金 绝热剪切敏感性 

分 类 号：TG146.4[一般工业技术—材料科学与工程]