http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Cheenepalli Nagarjuna,Sheetal Kumar Dewangan,Ashutosh Sharma,Kwan Lee,홍순직,안병민 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.7
An equiatomic CoCrFeMnNi high entropy alloy (HEA) was prepared by the gas atomization process. In addition, highenergymilling was carried out to study the effects of milling parameters on the morphology and crystallographic propertiesof HEA powders. Phase identification and morphology of milled powders were observed by X-ray diffraction and scanningelectron microscopy, respectively. Both the atomized and milled powders exhibited a single-phase face-centered cubic solidsolution. The resultant crystallite size (CS) and lattice strain (LS) of milled HEAs were estimated using the WilliamsonHall method and predicted using an artificial neural network (ANN) approach. With increasing the milling time from 0 to240 min, the CS decreased from 39.7 to 6.56 nm and the LS increased from 0.25%–1.48%, respectively. Furthermore, thedeveloped ANN modeling provides an excellent method for the prediction of the CS and LS with excellent accuracies of96.25% and 93.43%, respectively.
Yoon, Suk-min,Nagarjuna, Cheenepalli,Shin, Dong-won,Lee, Chul-hee,Madavali, Babu,Hong, Soon-jik,Lee, Kap-ho The Korean Powder Metallurgy Institute 2017 한국분말재료학회지 (KPMI) Vol.24 No.5
In this study, Bi-Sb-Te thermoelectric materials are produced by mechanical alloying (MA) and spark plasma sintering (SPS). To examine the influence of the milling atmosphere on the microstructure and thermo-electric (TE) properties, a p-type Bi-Sb-Te composite powder is mechanically alloyed in the presence of argon and air atmospheres. The oxygen content increases to 55% when the powder is milled in the air atmosphere, compared with argon. All grains are similar in size and uniformly, distributed in both atmospheric sintered samples. The Seebeck coefficient is higher, while the electrical conductivity is lower in the MA (Air) sample due to a low carrier concentration compared to the MA (Ar) sintered sample. The maximum figure of merit (ZT) is 0.91 and 0.82 at 350 K for the MA (Ar) and MA (Air) sintered samples, respectively. The slight enhancement in the ZT value is due to the decrease in the oxygen content during the MA (Ar) process. Moreover, the combination of mechanical alloying and SPS process shows a higher hardness and density values for the sintered samples.