CAJ | 학술논문

对Ca含量为2wt％的挤压态X20镁合金在410℃固溶处理20 h,采用光学显微镜(OM)、扫描电镜(SEM)结合能谱分析(EDS)以及透射电镜(TEM)对固溶处理前后的组织进行了表征,利用XRD衍射仪考察了固溶处理前后合金的相组成.结果表明,经固溶处理后,合金初始组织中β-Mg17Al12相的数量明显减少,同时析出新相Al2Ca.Al2Ca的形成可归结于残余β-Mg17Al12中高的Ca原子所造成的Mg原子被Ca原子取代,同时Al2Ca相自身高的结构稳定性也是其在Mg-Ca和Al-Ca系竞争析出中胜出的原因.
대Ca함량위2wt％적제압태X20미합금재410℃고용처리20 h,채용광학현미경(OM)、소묘전경(SEM)결합능보분석(EDS)이급투사전경(TEM)대고용처리전후적조직진행료표정,이용XRD연사의고찰료고용처리전후합금적상조성.결과표명,경고용처리후,합금초시조직중β-Mg17Al12상적수량명현감소,동시석출신상Al2Ca.Al2Ca적형성가귀결우잔여β-Mg17Al12중고적Ca원자소조성적Mg원자피Ca원자취대,동시Al2Ca상자신고적결구은정성야시기재Mg-Ca화Al-Ca계경쟁석출중성출적원인.
The as-extruded X20 magnesium alloys containing 2.0wt％ Ca were solution-treated at 410 ℃ for 20 h.The microstructures before and after solution treatment were observed by optical microscope (OM),scanning electron microscope (SEM) together with an energy dispersive spectroscope (EDS),and transmission electron microscope (TEM).The phase compositions before and after solution treatment were confirmed by X-ray diffraction (XRD).The results show that the amount ofβ-Mg17Al12 phases decreases remarkably after solution treatment,and new Al2Ca phases are formed.The formation of Al2Ca phase might be due to high concentration of Ca atoms in residual β-Mg17Al12 phases,which leads the place of Mg atoms to be substituted by Ca.On the other hand,Al2Ca phase could be also described as a completing product between Al-Ca system and Mg-Ca system intermetallics due to its high structural stability.