Kyushu University · Engineering
Professor Tomonori Kitashima's research lab specializes in computational materials science and additive manufacturing, with a focus on microstructure design and control in advanced metallic alloys. The lab investigates phase transformations, solidification processes, and defect engineering in multicomponent and pure metals using advanced simulation techniques such as the phase-field method and CALPHAD, particularly for applications in aerospace and energy systems. A key research direction involves optimizing laser-based additive manufacturing processes—such as selective laser melting and laser powder bed fusion—using tailored beam profiles (e.g., flat-top) to achieve single-crystal-like microstructures with controlled texture and reduced grain boundaries.
Figures are computed from collected data and may differ slightly.
The development of an effective microstructure design method for multicomponent alloys is of considerable importance for improving both the design of alloys and the design of processes for producing alloys with unique properties. The coupling of the phase-field method and the calculation of phase diagrams (CALPHAD) method can be used for predicting the evolution of microstructures in multicomponent alloys. Such predictions make use of CALPHAD thermodynamic information with the chemical free ener
The exploration of flat-top laser profile in fabricating a single crystal (SX) structure using selective laser melting (SLM) in pure Ni was investigated. Optimization of the parameters led to the formation of a planar melt pool. A homogeneous near-{001}<100> texture with suppressed high-angle grain boundary (HAGB) in high building heights of >20 mm was achieved without an SX seed. In addition, the planar melt pool suppressed the geometrically necessary dislocation accumulation and prevented stra
The effects of annealing on the microstructure of pure Ni fabricated by laser powder bed fusion (LPBF) were investigated using two different beam profiles: Gaussian and flat-top. The dislocations in the as-fabricated samples were predominantly arranged as statistically stored dislocations, and the low driving force resulting from the insufficient accumulation of geometrically necessary dislocations (GNDs) in the as-fabricated specimens caused minimal static recrystallization in the as-annealed s
Oxygen dissolution in titanium during oxidation is simulated with oxide/metal interface migration using a finite volume method. In this simulation, the oxidation rate resulting from both oxide growth and oxygen penetration into a metal are taken into account. The results show the temperature dependency of oxygen concentration at the oxide/metal interface in the metal, which is about 21 at% up to 600°C, and increases drastically to the oxygen solubility limit at temperatures above 600°C. This sug
Open papers in the app to read, cite, and organize with AI.
