摘要
采用铜模浇铸法制备Hf44.5Cu27Ni13.5Ti5Al10块体非晶合金,并对其进行等温退火处理。利用X射线衍射仪(XRD)和透射电镜(TEM)对非晶合金的晶化行为进行了分析,并通过MTS810实验机及场发射扫描电子显微镜(FESEM)研究了等温退火对合金力学性能的影响。结果表明,该非晶合金等温退火相转变进程为:非晶→非晶+Al16 Hf6Ni7→非晶+Al16 Hf6Ni7+CuTi2→CuHf2+CuTi2。合金断裂强度随退火温度的升高先增大后减小。743 K等温退火后,合金断裂强度达到最大值2400 MPa,弹性应变为3.0%。在Hf44.5Cu27Ni13.5Ti5Al10块体非晶合金压缩断口上观察到纳米级韧窝及周期性条纹结构。随着退火温度的升高,周期性条纹间距逐渐减小直至消失,断口形貌呈现为脆性解理断裂的河流状花样。
Hf44.5Cu27Ni13.5Ti5Al10 bulk amorphous alloy was prepared by copper mold casting process,and then isothermal annealing treatment at different temperatures was carried out.Crystallization behavior of the amorphous alloy was investigated by X-ray diffraction（XRD） and transmission electron microscopy（TEM）.The effects of isothermal annealing on mechanical properties of the alloy were studied by a MTS810 tester and field emission scanning electron microscopy（FESEM）.The results indicate that the crystallization of the alloy proceeds by the process of Am（amorphous state）→Am＋Al16Hf6Ni7→Am＋Al16Hf6Ni7＋CuTi2→ CuHf2＋CuTi2.The fracture strength of the alloy presents first increases,then decreases with the increase of annealing temperature.After annealing at 743 K,the fracture strength reaches the maximum value of 2400 MPa with elastic strain of 3.0%.The nanoscale dimples and periodic corrugations are observed on the fracture surface.The corrugation spacing decreases gradually and eventually disappears with the increase of annealing temperature.The fracture morphology is characterized by river shape pattern of brittle cleavage fracture.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2011年第10期22-26,共5页
Transactions of Materials and Heat Treatment
基金
国家重点基础研究发展计划(2010CB731600)
关键词
Hf-基非晶合金
等温退火
周期性条纹
力学性能
Hf-based amorphous alloy
isothermal annealing
periodic corrugation
mechanical property
