CAJ | 학술논문

在Gleeble?1500热模拟机上对Al?4.10Cu?1.42Mg?0.57Mn?0.12Zr合金在变形温度300°C和应变速度10 s?1下进行热压缩变形，真应变分别为0.2、0.4、0.6和0.8。通过X射线衍射仪、扫描电镜和透射电镜研究合金变形过程中复杂的动态显微组织演变。结果表明：真应力随着应变的增加而迅速增大至峰值，之后随着应变的增加而趋于稳定，呈现动态软化特征。随着应变的增大，位错缠结成胞状与亚晶结构，表明变形过程中发生动态回复。动态析出相S相、θ相和Al3Zr相在变形过程中粗化速度加快。铝基体中析出连续的S相，并发现有不连续的S相在Al3Zr相附近和亚晶界处形核析出。Al3Zr相相对比较稳定，易于在位错和亚晶界处析出。流动软化机制是由于动态回复和动态析出导致位错密度减少而引起的。
재Gleeble?1500열모의궤상대Al?4.10Cu?1.42Mg?0.57Mn?0.12Zr합금재변형온도300°C화응변속도10 s?1하진행열압축변형，진응변분별위0.2、0.4、0.6화0.8。통과X사선연사의、소묘전경화투사전경연구합금변형과정중복잡적동태현미조직연변。결과표명：진응력수착응변적증가이신속증대지봉치，지후수착응변적증가이추우은정，정현동태연화특정。수착응변적증대，위착전결성포상여아정결구，표명변형과정중발생동태회복。동태석출상S상、θ상화Al3Zr상재변형과정중조화속도가쾌。려기체중석출련속적S상，병발현유불련속적S상재Al3Zr상부근화아정계처형핵석출。Al3Zr상상대비교은정，역우재위착화아정계처석출。류동연화궤제시유우동태회복화동태석출도치위착밀도감소이인기적。
The Al?4.10Cu?1.42Mg?0.57Mn?0.12Zr alloy was compressed to different strains at deformation temperature of 300 oC and strain rate of 10 s?1 on Gleeble?1500 system. The dynamic complex microstructures evolutions were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The true stress?true strain curves exhibited a peak stress at critical strain, after which the flow stresses decreased monotonically, showing a dynamic flow softening. As the strain increased, the dislocation tangled to cell structure and sub-grain structure, which indicated the occurrence of dynamic recovery during deformation. Dynamic precipitations ofS (Al2CuMg),θ (Al2Cu) and Al3Zr phase were accelerated and coarsened by deformation. ContinuousS phases precipitated in the Al matrix and discontinuousS phases were found to be nucleated near the Al3Zr phase and at the sub-grain boundary. The flow softening mechanism was resulted from the reduction of dislocation density which attributed to dynamic recovery and precipitates coarsening.