摘要
采用电弧熔炼法熔炼Ni48Mn31Ga21和Ni50Mn25Ga25两种合金,并对这两种合金进行了热处理,借助交流磁化率测定、金相显微镜观察、X射线衍射等手段研究了热处理工艺条件对非化学计量比的Ni48Mn31Ga21合金马氏体相变和结构有序度的影响。结果表明:(1)Ni48Mn31Ga21合金相变特征温度为:Ms=305K,Mf=297K,As=313K,Af=318K,居里温度Tc=366K;(2)与空冷态相比,淬火态的马氏体转变量降低,经过400℃退火后,随着保温时间t的延长,马氏体转变量上升,当t=50h时达到最大值;(3)Ni48Mn31Ga21合金经过900℃×4d+400℃×50h热处理后,有序度明显提高。
Polycrystalline ingots of Ni48Mn31Ga21 and Ni50 Mn25Ga25 alloys were melted by the arc melter,and different heat treatments were processed in two alloys.The effect of heattreatrnent conditions on martenisitic transformation and structural ordering of off-stoichiometric Ni48Mn31Ga21 alloys was studied by means of ae susceptibility measurements,optical microscope, X-ray diffraction and so on. The results indicate：（ 1 ）for off-stoichiometrie Ni48Mn31Ga21 alloy, the temperature of martensitic transformation were as follows： Ms= 305K,Ml= 297K,As = 313K,Al = 318K, Tc = 366K; （2） compared with the dry quenching sample,the matensite fraction of the quenching sample deduced, after tempering treatment of 400℃, the matertsite fraction went up with the increase of time. When time is 50h,the martensite fraction got to the maximum; （3）After the alloy was treated at 900℃ for 4 days, then 400℃ for 50h, we could find the ordering of the alloy was obviously improved.
出处
《金属功能材料》
CAS
2006年第6期8-12,共5页
Metallic Functional Materials
