本研究藉由合金設計原理、機械性質及實際的熱處理驗證，透過 光學顯微鏡(OM)、高溫熱示差掃描分析儀(HTDSC)、渦電流導電度計 (%IACS)、電子顯微鏡(TEM & SEM)等對微結構的分析，來探討合金 元素對 Al-Zn-Mg-Cu 合金之固溶溫度與淬火敏感性之影響。 結果顯示，降低銅含量後，均質化處理將使 Al-Zn-Mg-Cu 合金 之共晶相 T 相(Mg3Zn3Al2)與 η 相(MgZn2)均回溶於鋁基地，且不會析 出低熔點(~495°C)的 S 相(Al2CuMg)，因此提高了合金之固溶溫度， 增加合金固溶熱處理之效率;另外藉由提高合金之鋅含量，以增加強 化相 η′ (MgZn2)之析出量，來彌補因 Cu 降低所減損合金之機械強度， 結果顯示鋅原子不但可以提升合金強度外，對於合金延性也沒有不良 減損，且可以與 Zr 原子加成改善合金之淬火敏感性。 ;Based on the principle of design, mechanical properties and heat treatment of the alloy, and by using the optical microscope (OM), the high temperature differential scanning calorimetry (HTDSC), the electrical conductivity meter (% IACS), and the electron microscope (TEM & SEM) to analyze the microstructure of the alloy. In order to explore the impact the alloy has on the Al-Zn-Mg-Cu alloy solution temperature and quenching sensitivity. The results show that the eutectic T phase (Mg3Zn3Al2) and the η phase (MgZn2) of the Al-Zn-Mg-Cu alloy are homogeneously dissolved in the aluminum matrix and doesn’t precipitate the low melting point’s S phase (Al2CuMg) after the copper content is reduced. Thus, increases the solution temperature of the alloy and improves the efficiency of the solution heat treatment. By increasing the zinc content of the alloy to increase the precipitation amount of the strengthening phase η′(MgZn2) to compensate for the reduction of the mechanical strength of the reduced alloy due to copper. The results show that the zinc atom not only improves the strength of the alloy, but also has no damage to the ductility of the alloy, and can improve the quenching sensitivity of the alloy with the addition of zirconium atom.
