CoCrFeMnNi 고엔트로피 합금에서 탄소 첨가 및 재결정열처리가 미세구조 및 기계적 특성에 미치는 영향

• Published in: 대한금속·재료학회지, 56(1) Vol. 56; no. 1; pp. 26 - 33
• Main Authors: 고준영, Jun Yeong Ko, 송재숙, Jae Sook Song, 홍순익, Sun Ig Hong
• Format: Journal Article
• Language: Korean
• Published: 대한금속재료학회 05.01.2018; 대한금속·재료학회
• Subjects: carbide; carbon; CoCrFeMnNi; high entropy alloys; interstitial; 재료공학
• ISSN: 1738-8228; 2288-8241

The effect of carbon addition on the cast and rolled microstructures of CoCrFeMnNi high entropy alloys were studied. Both as-cast CoCrFeMnNi and CoCrFeMnNiC 0.1 alloys have a dendritic microstructure. Small carbide particles were observed at the inter-dendritic region in the as-cast CoCrFeMnNiC 0.1 and elongated-grained structure with aligned carbides were developed at grain boundaries in CoCrFeMnNiC 0.1 after homogenization. The grain size decreased from 9.2 μm to 5.8 μm with the addition of 0.1 wt% carbon. The decrease in grain size is due to its high stored cold work energy during deformation processing, resulting in more active recrystallization in CoCrFeMnNiC 0.1 and the pinning effect of carbides. The strengthening in CoCrFeMnNiC 0.1 is most likely attributed to solid solution strengthening and nanoscale carbide strengthening, because grain size strengthening was found to be not as effective. (Received May 23, 2017; Accepted September 25, 2017)