摘要
采用 Perkin-Elmer DSC7型差示扫描量热仪对深过冷快淬法制取的 Ni_(68)B_(21)Si_(11)三维金属玻璃进行等温、变温热分析,从液态合金的净化,非晶合金的预退火处理及冷却速率三个方面考察了 Ni_(68)B_(21)Si_(11)非晶合金的热稳定性。研究发现:由于大幅度地消除了合金内的预存晶核,深过冷快淬法形成的非晶合金的热稳定性显著提高,此法获得的 Ni_(68)B_(21)Si_(11)非晶合金在400K 下预期寿命提高了一个数量级;非晶合金的预退火处理将导致初始晶化温度 T_λ 和晶化热ΔH 下降;冷却速率对热稳定性影响较小。
Under the isothermal and linear heating conditions respectively,the thermal sta-bility of 3-dimensional metallic glass Ni_(68)B_(21)Si_(11) produced by rapid quenching denucleated melt(RQDM)has been systematically studied by means of PE DSC7 differential scanningcalorimetry in the three influencing factors:denucleation of liquid alloy prior to rapidquenching,pre-anneal treatment of amorphous specimens,and cooling rate.The main contri-butions are represented by the following aspects.First,the thermal stability of metallic glassprepared by RQDM is obviously enhanced because of removal of pre-existing nuclei inadvance.This is substantiated by one of experimental data that the projected life of3-dimensional metallic glass Ni_(68)B_(21)Si_(11) is increased by an order of magnitude at 400K.Secondly,pre-anneal treatment of the amorphous alloy leads to a reduction of temperature foronset of crystallization,T_x,and crystallization heat,ΔH.Finally,quenching rates have little ef-fect on the thermal stability of amorphous alloys.
基金
国家自然科学基金
5870066
关键词
合金
净化
分析
热稳定性
金属玻璃
alloy denucleation
DSC analysis
thermal stability
