本研究藉由光學顯微鏡(OM)、差示掃描量熱儀(DSC)、穿透式電子顯微鏡(TEM)、掃描式電子顯微鏡(SEM + EBSD)等來分析微量Zr/Sc與均質化對Al-4.5Zn-1.5Mg(AA7005)合金微結構之影響，並以硬度及拉伸試驗，探討其T6態AA7005鋁合金機械性質；結果顯示，含0.05Sc(wt%)之Al-4.5Zn-1.5Mg合金之鑄態、均質化與T6態已再結晶微結構，其晶粒細化效果均較含0.1Zr(wt%)合金顯著；且經均質化處理後，含Sc之合金於鋁基地所析出之Al3Sc顆粒，雖較含Zr之合金所析出之Al3Zr顆粒較粗化，但卻更能有效抑制合金T6態的再結晶與晶粒成長；在T6態下，較低量Sc(0.05%Sc)的添加其對機械性質的提升優於較大量Zr(0.1Zr)的添加；另外，相較於一段式均質化熱處理，兩段式均質化可使散佈顆粒相(Al3Zr/Al3Sc)更為細小；導致經兩段式均質化之合金的T6態機械強度均優於所對應合金的一段式均質化者；而不同均質化對含Zr之Al-4.5Zn-1.5Mg合金之Al3Zr散佈顆粒相之粗細差異大於含Sc合金，故其機械強度提升效率略優於含Sc合金。;The effects of minor Zr/Sc and homogenization on the microstructural evolution and mechanical properties in T6 state of Al-4.5Zn-1.5Mg alloy were investigated by optical microscopy (OM), differential scanning calorimetry (DSC) measurements, transmission electron microscopy (TEM), scanning electron microscopy- electron back-scattered diffraction (SEM-EBSD), hardness test and tensile test. The results demonstrated that the addition of 0.05Sc(wt%) had a better effect on grain refining than 0.1Zr(wt%) in a state of as-cast, as- homogenization and recrystallized section of T6 state in Al-4.5Zn-1.5Mg alloy. Also, the alloy with less addition (0.05wt%)Sc had a better effect on inhibiting recrystallization and grain growth than the alloy with more addition (0.1wt%)Zr. As a result, grain refinement and improvement of mechanical properties were observed after T6 temper although the precipitates of the alloy with minor Sc, which precipitated Al3Sc dispersoids, were coarser than the alloy with minor Zr, which precipitated Al3Zr dispersoids. Otherwise, two-stage homogenization treatment would get a smaller and denser Al3Zr/ Al3Sc dispersoids, which had more positive effect on grain refinement and improvement of mechanical properties than one-stage homogenization. However, for the alloy with minor Zr, different homogenization treatments made a greater divergences on the size and distribution of the dispersoids than the alloy with minor Sc. Therefore, the mechanical properties caused by different homogenization of the alloy with minor Zr had more improved than the alloy with minor Sc
