CAJ | 학술논문

运用固体与分子经验电子理论(EET)对Mg-Al合金熔体进行价电子结构分析,在此基础上构建了基本结构模型,获得熔体的基本结构信息.通过分析升温和降温过程中镁合金熔体黏度-温度关系曲线V(t)的不可逆现象,间接地对熔体结构信息的不可逆变化作出判断.结果表明:原子间各键共价电子对数na的差异是造成熔体结构信息变化的根本原因,直接导致合金熔体存在微观不均匀性;当温度升高至730℃附近时,结构相对稳定的原子集团内部的Al-MgⅢ(c)键开始发生断裂,熔体结构达到新平衡的相对均匀状态;遗传自固态组织中微观不平衡结构的消失和原子集团内部Al-MgⅢ键的破坏及原子发生的不可逆重排是曲线V(t)发生不可逆变化的本质原因.这对于深入认识镁合金熔体结构信息及探索凝固微观机制具有重要理论意义.
운용고체여분자경험전자이론(EET)대Mg-Al합금용체진행개전자결구분석,재차기출상구건료기본결구모형,획득용체적기본결구신식.통과분석승온화강온과정중미합금용체점도-온도관계곡선V(t)적불가역현상,간접지대용체결구신식적불가역변화작출판단.결과표명:원자간각건공개전자대수na적차이시조성용체결구신식변화적근본원인,직접도치합금용체존재미관불균균성;당온도승고지730℃부근시,결구상대은정적원자집단내부적Al-MgⅢ(c)건개시발생단렬,용체결구체도신평형적상대균균상태;유전자고태조직중미관불평형결구적소실화원자집단내부Al-MgⅢ건적파배급원자발생적불가역중배시곡선V(t)발생불가역변화적본질원인.저대우심입인식미합금용체결구신식급탐색응고미관궤제구유중요이론의의.
Through the empirical electron theory of solids and molecules (EET), the valence electron structure of Mg-Al alloy melt was analyzed. Based on the analysis, the basic structure model was established and the melt structural information was obtained. By analyzing the irreversible phenomenon of viscosity-temperature relationship curve V(t) of magnesium alloy melt in the temperature interval of ascent and descent, the irreversible change of the melt structural information would be judged indirectly. The results show that the number difference of covalent electron pair na of each bond between atoms is the ultimate reason of the different melt structural information, which induces micro-inhomogeneity in alloy melt directly; at near 730 ℃, Al-MgⅢ(c) bonds in the atomic clusters with relatively stable structure begin to break. At this time, the melt structure achieves a new equilibratory and relatively homogeneous state. Disappearance of micro-nonequilibrium structure inherited from solidified structure, breakage of Al-MgⅢ(c) bonds in the atomic clusters and irreversible rearrangement of atoms are the essential reason of irreversible change of curve V(t). It is very important for further understanding the melt structural information of magnesium alloy and exploring solidification micro-mechanics.