東北大学 · Engineering
Huakang Bian 교수의 연구실은 고온 구조재료, 특히 니켈- cobalt 기반 니켈기 고온합금과 고엔트로피 합금의 나노구조 설계 및 거동을 중심으로 연구를 진행하고 있습니다. 특히, 고온에서의 상 안정성 향상을 위해 나노미세 구조 제어, 원자적 분포의 최적화, 비균형 응고 조건에서의 미세구조 형성 메커니즘을 규명하고자 합니다. 연구는 나노입자 분포, 상호작용, 비균형 응고 조건이 기계적 성질에 미치는 영향을 다각도로 분석합니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
The properties of superalloys are typically deteriorated by the coarsening of the nano-sized γ′ phase, which is the primary strengthening component at high temperatures. Stabilizing the γ′ phase represents one of the key challenges in developing next-generation superalloys. Herein, we fabricate a cobalt-nickel-based superalloy with a nanoscale coherent γ′ phase, (Ni,Co)3(Al,Ti,Nb), which is isolated by stacking-fault ribbons in the alloy matrix as a result of the Suzuki segregation of alloying a
We propose a novel strengthening strategy that involves the introduction of a high-entropy nanoscale phase (HENP) and semicoherent refractory nanoparticle into the A2 matrix of an as-cast equimolar HfMoNbTaTi refractory high-entropy alloy (RHEA). Based on the design concept of low difference in elemental melting points, equiaxed grains with slight segregation were obtained. The HENP was characterized as a disordered near-coherent structure with a composition significantly similar to the matrix t
For components built by powder bed fusion with electron beam (PBF-EB), the resulting microstructure arising from non-equilibrium solidification, microsegregation and the formation of interdendritic phases significantly affects the material properties. Notably, the powder characteristics influence the heat absorption and conduction, thereby altering the molten pool behavior and solidification parameters. However, the effect of the powder feedstock on solidification during PBF has not been widely
Solid solution phases dominate the thermodynamic competition with intermetallic phases in high-entropy alloys (HEAs), known as the high-entropy effect. However, owing to inevitable local substitutions in multi-component intermetallics (MCIMs), imposed thermodynamic changes are often overlooked. This study investigated a partially disordered MCIM, C14 Laves phase, in a dual-phase CrHfNbTaTi refractory HEA. The chemical formula and site preferences were determined based on the observation of spati
