以五元或五元以上等莫耳元素組成之高熵合金設計概念已受國內外矚目，漸漸成為學術界爭相研究的目標。從2010年美國空軍實驗室開始發表一系列耐火高熵合金，第一組NbTaMoW、VNbTaMoW，具有優異的高溫壓縮強度 (1600°C時為477 MPa)，缺點為室溫延性不佳且密度過高，不利於實際應用，隨後又發表第二組耐火高熵合金HfNbTaTiZr，其室溫壓縮塑性應變量大於50%，具有很好的延性，而在之後研究中，也逐漸提升其高溫上的使用程度，增加此合金系在航太上未來使用的可能。而學長研究發現在核能上所能承受的使用溫度介於耐火合金的使用範圍，因此設計新合金系統於核能領域，這次也以此合金系統進行改良開發。
之前學長所研發新型的高熵合金 MV030、MV050、MV075 和MV100 ，結構上都屬於BCC單一固溶相結構。但是因為有 Laves phase 的生成，使的機械性質中韌性表現不足，唯有 MV030 和 MV050 表現良好。另外在抗氧化上，充分展現耐火合金不抗氧化的特性，氧化增重表現不佳。因此最後選取 MV030 成分改質進行本次研究。
在本次研究中，將原本 MV030 中 V 元素捨去，並添加 0.3 份Nb元素，形成新的合金並命名M，並分別進行添加 Al、Cr、Si 的一元、二元及三元合金配比。從中挑選出 A04M、A03C01M、A03M-S2、A03M-S3 以及 A03M-C1S2 進行高溫性質包括氧化增重以及高溫壓縮試驗。
由實驗結果得知，六種合金皆為 BCC 之結構，其中添加 Si 之合金有矽化物 (hexagonal 結構) 峰值出現；室溫強度方面，Al、Cr、Si 都有助益強度上升，不過 Cr、Si 元素添加會大幅犧牲材料加工性；高溫強度方面，600 °C、800 °C 下 Al 增量、Si 添加有明顯強化材料的趨勢，但溫度再升高，Al 添加試片反而因為熔點低強度迅速掉落；高溫抗氧化方面，Al、Si 添加對合金抗氧化力有明顯幫助，其中在 Cr、Si 微量添加可以抑制 800 °C pesting 的產生。
綜合來看，本研究 A04M 及 A03M-C1S2 合金，兼顧了在 800 °C 前高溫強度及高溫抗氧化能力，具有 800°C 高溫應用的潛力。

In previous study, a new design of refractory high-entropy alloy, MV series, for nuclear structure materials was developed. In this study, new reviced alloys based on MV series are developed. The new revised alloy is Mo0.3Nb1.3TiZr. due to the poor oxidation resistance ,we want to add the Al, Cr, Si elements in Mo0.3Nb1.3TiZr individually and integratedly. The melting point of the addition alloys is around 2210 ~2350 ˚C. The density is around 6.5~7 g/cm3. Simple BCC structure is observed in the as-cast state of Al-addition alloys, A03C01M and A04C01M. With more Cr and Si addition, laves phase and silicide will be precipitated in the alloys and made the materials fragile, although they can enhance the yield stress. With three elements added, alloy has the highest yield stress 1435 MPa.These alloys with elements addition have Vickers hardness around 375 to 450 Hv and compression yield strength around 1100 to 1500 MPa. Impressively, M and A04M possess the compression ductility more than 50%. By the high temperature compression test, A04M, A04M-S2 show good thermal-softening resistance until 800 ˚C, retaining 826 MPa and 750 MPa. When it comes to oxidation weight gain experiment, A04M-S2 and A03M-C1S2 show the best oxidation resistance at 800 and 1000 ˚C, about 1 and 25 mg/cm^2.

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