Ti-Cu積層造形合金における熱処理による析出形態の制御と機構解明

Intermetallic compounds (IMCs), known for their hardness, play an important role in the precipitation strengthening of alloys. However, excessive amounts or as large particles can result embrittlement material. Thus, controlling distribution IMCs among matrix is crucial design strong and ductile In this research, a supersaturated Ti-Cu alloy formed by Laser Powder Bed Fusion (L-PBF) was heat-treated at different phase regions to produce lamellar, network, dispersed distributions Ti2Cu IMC precipitates. To comprehensively understand formation mechanisms each structure, in-situ microstructure observation performed during heat-treatments. The lamellar structure obtained from heat treatment above beta-transus temperature, found derive rejection Cu atoms towards boundaries alpha grains cooling. network heat-treatment α+β region involved Cu-rich β-Ti layer between α-Ti heating, subsequent into α-encapsulating upon Finally, observed regular nucleation growth α+IMC region.