CAJ | 학술논문

采用金相分析、扫描电镜、能谱分析、DSC等手段研究含钪Al-Zn-Mg-Zr合金均匀化态显微组织的演变。结果表明：在合金铸态组织中存在大量的枝晶偏析，在晶界处存在很多低熔点共晶相，主要元素在枝晶内部区域呈周期性变化；合金中元素Zn、Mg和Cu在晶内及晶界分布不均匀；在均匀化过程中，随着均匀化温度的升高或时间的延长，残留相逐渐溶入基体，元素分布逐渐均匀。合金的过烧温度为476.7°C。当均匀化温度升高到480°C时，合金中开始出现复熔球和三角晶界。综合考虑：合金的最佳均匀化制度为470°C，24 h。
채용금상분석、소묘전경、능보분석、DSC등수단연구함항Al-Zn-Mg-Zr합금균균화태현미조직적연변。결과표명：재합금주태조직중존재대량적지정편석，재정계처존재흔다저용점공정상，주요원소재지정내부구역정주기성변화；합금중원소Zn、Mg화Cu재정내급정계분포불균균；재균균화과정중，수착균균화온도적승고혹시간적연장，잔류상축점용입기체，원소분포축점균균。합금적과소온도위476.7°C。당균균화온도승고도480°C시，합금중개시출현복용구화삼각정계。종합고필：합금적최가균균화제도위470°C，24 h。
The microstructural evolution of Al-Zn-Mg-Zr alloy with trace amount of Sc during homogenization treatment was studied by means of metallographic analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and differential scanning calorimetry (DSC). The results show that serious dendritic segregation exists in studied alloy ingot. There are many eutectic phases with low melting-point at grain boundary and the distribution of main elements along interdendritic region varies periodically. Elements Zn, Mg and Cu distribute unevenly from grain boundary to the inside of alloy. With increasing the homogenization temperature or prolonging the holding time, the residual phases are dissolved into matrix α(Al) gradually during homogenization treatment, all elements become more homogenized. The overburnt temperature of studied alloy is 476.7 °C. When homogenization temperature increases to 480 °C, some spherical phases and redissolved triangular constituents at grain boundaries can be easily observed. Combined with microstructural evolution and differential scanning calorimeter, the optimum homogenization parameter is at 470 °C for 24 h.