AlCoCrFeNiTi高熵合金高溫降伏強度之研究

Research on the High Temperature Yield Strength Evolution of AlCoCrFeNiTi High Entropy Alloys

胡秉淳(Bing-Chuen Hu) ； 陳彥儒(Yen-Ju Chen) ； 葉安洲(An-Chou Yeh) ； 張耀仁(Yao Jen Chang)

《鍛造》 27卷4期 (2018/12) Pp. 21-26

摘要

高熵合金具有高溫強度、硬度等材料特性，可突破傳統合金的性能，未來可應用在高溫高壓的嚴苛環境中。本研究使用AlCoCrFiNiTi高熵合金作為研究主題，針對其高溫機械特性進行探討。目前針對高熵合金鍛造性研究甚少，本文針對此高熵合金的可鍛造性進行評析，並針對不同狀態下的材料進行高溫實驗測試，包括鑄造狀態、均質化、及高溫成形後。使用高溫壓縮試驗機Gleeble Machine 3500（ITRI），針對不同狀態下的材料進行測試，AlCoCrFeNiTi材料在1,100℃下具有高屈服強度（159MPa），應變速率為1s^(-1)。並在高度壓縮率70%後，在試件表面上沒有觀察到可見的裂縫，證明了AlCoCrFeNiTi材料具有高降伏強度和良好的可成形性。

並列摘要

Comparing with the properties of traditional metallic materials, high-entropy alloy (HEA) has usually exhibited higher yield strength and hardness. Scientists and engineers are very keen to explore the possibilities to use HEA in harsh environments with high temperature and pressure. So far, there have been very few reported studies on the yield strength of HEAs at elevated temperatures. In this study, AlCoCrFeNiTi HEA was chosen to investigate its stress-strain relations under high temperature. Three different conditions of AlCoCrFeNiTi were studied (namely, as-cast, homogenized, and after deformation) The high temperature compression tests were conducted by using a Gleeble 3500 machine. AlCoCrFeNiTi material showed a high yield strength (159MPa) under 1,100°C with a strain rate of 1s^(-1). However, no visible cracks were observed on the surface of specimen after 70% of height reduction, which indicated that AlCoCrFeNiTi material possesses high yield strength and good formability.