CAJ | 학술논문

利用消失模铸造工艺,通过正交实验合金化工艺,重点研究了表面合金化的形成机理,建立了消失模铸件表面合金化模型,分析了合金化过程的动力。在不同真空度、金属粒度、温度为780℃的条件下进行浇注,发现在镁合金基体表面形成均匀的合金化层,通过扫描电镜(SEM)分析表层组织变化,对生成的新相进行微区成分和表层线成分分析。研究表明,在表层生成的新相主要是 Mg17 Al12,并且表层显微硬度明显高于基体。分析了合金化机理和影响形成均匀合金化层的主要因素,得出了合金化颗粒粒度和铸渗动力在合金化过程中起关键作用,随着合金化颗粒粒度和真空度增大,表面合金化效果明显得到了提高。
이용소실모주조공예,통과정교실험합금화공예,중점연구료표면합금화적형성궤리,건립료소실모주건표면합금화모형,분석료합금화과정적동력。재불동진공도、금속립도、온도위780℃적조건하진행요주,발현재미합금기체표면형성균균적합금화층,통과소묘전경(SEM)분석표층조직변화,대생성적신상진행미구성분화표층선성분분석。연구표명,재표층생성적신상주요시 Mg17 Al12,병차표층현미경도명현고우기체。분석료합금화궤리화영향형성균균합금화층적주요인소,득출료합금화과립립도화주삼동력재합금화과정중기관건작용,수착합금화과립립도화진공도증대,표면합금화효과명현득도료제고。
Surface alloying forming mechanism was investigated under lost foam casting (LFC ) technology through orthogonal experiment.Surface alloyed model was established and driving force was analyzed.Homoge-neous alloyed layer has been formed on the Mg-alloy matrix on condition that the vacuum degree and metal grain size were different,pouring temperature was 780 ℃ respectively,scanning electron microscopy (SEM)was used to examined the change of surface layer microstructure,micro area composition analysis of new phase formed on the matrix and line scan composition characteristics on the surface were carried out.The results show that the surface layer consists ofβ- Mg17 Al12 phase,micro-hardness value was enhanced greatly compared with the matrix.Analyzed the alloying mechanism and the important factors during the alloying process that influ-enced the formation of uniform alloyed layer,it has been found that alloying metal grain size and casting infil-tration driving force are the key factors in the experiment,with the increase of grain size and vacuum degree, the surface alloying effect has become better.