摘要
采用真空电弧熔炼结合水冷铜模吸铸法制备ZrCuAlNiCoNb大块非晶合金。采用XRD、AFM、SEM及纳米压痕分析手段研究等温退火对ZrCuAlNiCoNb非晶合金显微组织演变、硬度和杨氏模量的影响。结果表明,无论温度高低,退火均能使非晶合金中自由体积的数量减少。在低于玻璃化转变温度下退火,合金中自由体积数量下降,抑制了剪切带的形核,合金的硬度和杨氏模量随退火时间的增加而提高;在高于玻璃化转变温度下退火,短时间即可诱发纳米晶化,合金的硬度和杨氏模量均先增加,达到峰值后下降。ZrCuAlNiCoNb非晶合金力学性能的演变趋势是自由体积演变和纳米晶形核共同作用的结果。
ZrCuAlNiCoNb bulk amorphous alloys were prepared by arc melting technique plus copper mould casting method.The effect of isothermal annealing on the microstructural evolution,hardness and elastic modulus of ZrCuAlNiCoNb amorphous alloys was investigated using XRD,AFM,SEM and nanoindentation tests.The results show that the annealing can result in the decrease of the free volume in the amorphous alloys whether annealing temperature is high or low.When the annealing temperature is below the glass transition temperature,both the hardness and elastic modulus of the alloy increase with increasing annealing time,which is due to the reduction of the free volume and the inhibition of the nucleation of shear bands.When the annealing temperature is above the glass transition temperature,a short period of annealing can induce nanocrystallination,and both the hardness and elastic modulus increase initially with increasing annealing time,and decrease after reaching the peak values.This evolution trend of the mechanical properties results from co-effects of the free volume evolution and nanocrystal nucleation.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2013年第4期471-476,共6页
Materials Science and Engineering of Powder Metallurgy
基金
大学生创新性实验计划(LA10017)
粉末冶金国家重点实验室自主专项
关键词
非晶合金
等温退火
弹性模量
硬度
amorphous alloy
isothermal annealing
elastic modulus
hardness
