MEDIUM-ENTROPY ALLOYS WITH SPINODAL DECOMPOSITION-INDUCED EXTENDED SOLUBILITY

• Main Authors: DO HYEONSEOK, LEE BYEONGJOO, OH JINMOK, MOON JONGUN, PARK JEONGMIN, KANG NAMSEOK, SHIN HYUNKWON, KIM HYOUNGSEOP
• Format: Patent
• Language: English; Korean
• Published: 21.01.2020
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The present invention provides a medium-entropy alloy, which comprises: 25 to 35 at% of Cu; 25 to 35 at% of Fe; 25 to 35 at% of Mn; and up to 15 at% of Al. According to the present invention, the medium-entropy alloy reduces the addition amount of Co, Cr, Ni or the like, which are high-priced chemical elements used a lot in a high-entropy alloy, and combines Al, Cu, Fe and Mn, which are cheap chemical elements, thereby securing price competitiveness. Also, the medium-entropy alloy controls the content of Al of the alloy, thereby implementing weight reduction. At the same time, the medium-entropy alloy has excellent properties since the yield strength is equal to or more than 470 MPa, the tensile strength is equal to or more than 626 MPa, and the elongation rate is equal to or more than 36 % at the room temperature (298 K). 본 발명은 25 내지 35 at%의 Cu, 25 내지 35 at%의 Fe, 25 내지 35 at%의 Mn 및 최대 15at%의 Al을 포함하는 중엔트로피 합금을 제공한다. 본 발명에 따른 중엔트로피 합금은 고엔트로피 합금계에서 많이 사용되는 고가 원소인 Co, Cr, Ni 등의 첨가량을 줄이고, 저렴한 합금 원소인 Al, Cu, Fe, Mn을 조합하여 가격 경쟁력을 확보할 수 있으며, 합금의 Al 함량을 조절함으로써, 경량화도 이루어낼 수 있다. 동시에, 상기 중엔트로피 합금은 상온(298 K)에서의 항복강도가 470 MPa 이상, 인장강도 626 MPa 이상, 연신율 36% 이상으로 우수한 특성을 갖는다.