CAJ | 학술논문

采用低频电磁铸造技术制备Al?9Zn?2.8Mg?2.5Cu?xZr?ySc (x=0,0.15%,0.15%；y=0,0.05%,0.15%)合金，借助金相显微镜、扫描电镜、透射电镜、力学性能测试等手段分别对其均匀化、热挤压态、固溶态和时效态的组织与性能进行对比分析。结果表明：添加微量Sc和Zr，会在凝固过程中形成初生Al3(Sc,Zr)，可显著细化合金铸态晶粒；均匀化时形成的次生 Al3(Sc,Zr)粒子可以强烈钉扎位错和亚晶界，有效抑制变形组织的再结晶，显著提高合金的力学性能。与不含Sc、Zr的合金相比，含0.05%Sc和0.15%Zr的合金经固溶处理和峰值时效处理后其抗拉强度和屈服强度分别提高172 MPa和218 MPa，其强化作用主要来自含Sc、Zr化合物对合金起到的亚结构强化、析出强化和细晶强化。
채용저빈전자주조기술제비Al?9Zn?2.8Mg?2.5Cu?xZr?ySc (x=0,0.15%,0.15%；y=0,0.05%,0.15%)합금，차조금상현미경、소묘전경、투사전경、역학성능측시등수단분별대기균균화、열제압태、고용태화시효태적조직여성능진행대비분석。결과표명：첨가미량Sc화Zr，회재응고과정중형성초생Al3(Sc,Zr)，가현저세화합금주태정립；균균화시형성적차생 Al3(Sc,Zr)입자가이강렬정찰위착화아정계，유효억제변형조직적재결정，현저제고합금적역학성능。여불함Sc、Zr적합금상비，함0.05%Sc화0.15%Zr적합금경고용처리화봉치시효처리후기항랍강도화굴복강도분별제고172 MPa화218 MPa，기강화작용주요래자함Sc、Zr화합물대합금기도적아결구강화、석출강화화세정강화。
The Al?9Zn?2.8Mg?2.5Cu?xZr?ySc alloys (x=0, 0.15%, 0.15%; y=0, 0.05%, 0.15%), produced by low-frequent electromagnetic casting technology, were subjected to homogenization treatment, hot extrusion, solution and aging treatment. The effects of minor Sc and Zr addition on microstructure, recrystallization and properties of alloys were studied by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that Sc and Zr addition can refine grains of the as-cast alloy by precipitation of primary Al3(Sc,Zr) particles formed during solidification as heterogeneous nuclei. Secondary Al3(Sc,Zr) precipitates formed during homogenization treatment strongly pin the movement of dislocation and subgrain boundaries, which can effectively inhibit the alloys recrystallization. Compared with the alloy without Sc and Zr addition, the Al?Zn?Mg?Cu?Zr alloy with 0.05%Sc and 0.15%Zr shows the increase in tensile strength and yield strength by 172 MPa and 218 MPa, respectively. Strengthening comes from the contributions of precipitation, substructure and grain refining.