Kyoto University · 공학
Zhenghao Chen 교수의 연구실은 고엔트로피합금, 중엔트로피합금 및 첨단 체적합금의 나노스케일 기계적 거동을 중심으로 연구를 진행하고 있습니다. 특히, 결정방향, 입자 크기, 원자배열에 따른 비례 변형 거동과 미세구조 변화를 정량적으로 분석함으로써 고강도·고 ductility 합금의 설계 원리를 규명하고자 합니다. 연구는 주로 마이크로피라미드 압축 시험과 원자적 분석을 융합한 다스케일 기계적 성질 분석을 기반으로 합니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
A new route to achieve high strength and high ductility compositions in the Cr-Co-Ni medium entropy alloys (MEAs) is proposed, by controlling the solid solution hardening parameter (Mean Square Atomic Displacement, MSAD) and twinning propensity parameter (Stacking Fault Energy, SFE), respectively. The MSAD is calculated to increase with the increase in the Cr content and with the increase in the Ni/Co ratio at high Cr concentrations, while the SFE is calculated to decrease with the increase in t
The temperature-dependent yield strengths of [1¯23]-oriented single crystals of four quinary non-equiatomic Cr-Mn-Fe-Co-Ni high-entropy alloys (HEAs) were investigated at temperatures of 10-1173 K. They exhibit similar trends with a rapid decrease of the critical resolved shear stress (CRSS) from 10 K to 300 K, followed by a much slower rate of decrease with increasing temperature and a plateau above 873 K. The HEAs with the highest and lowest Cr contents exhibit the highest and lowest yield str
The plastic deformation behavior of a B2-ordered TiCrMo-15Al refractory high-entropy alloy (RHEA) has been investigated as a function of crystal orientation and specimen size by micropillar compression at room temperature, in an attempt to understand the origin for the brittle behavior of the B2 compound based on the identified operative slip systems and dislocation structures. Plastic flow is observed even at room temperature for all orientations investigated with the slip direction always bein
The plastic deformation behavior of single crystals of Fe3Ge with the L12 structure has been investigated at room temperature as a function of crystal orientation by micropillar compression tests. In addition to slip on (010), slip on (111) is observed to occur in Fe3Ge for the first time. The CRSS (critical resolved shear stress) for (111)[101¯] slip, estimated by extrapolating the size-dependent strength variation to the ‘bulk’ size, is ~240 MPa, which is almost 6 times that (~40 MPa) for (010
The plastic deformation behavior of single crystals of orthorhombic η-Fe2Al5 has been investigated by micropillar compression at room temperature as a function of crystal orientation and specimen size. Plastic flow is observed even at room temperature by the operation of six slip systems; (001)<010>, (001)<110>, (001)<130>, {22‾3}<110>, {311}<1‾03> and {301}<1‾03>. The CRSS values for the six identified slip systems are very high all in the range of 1.1∼1.5 GPa and do not vary much with specimen
