Grain Refinement Mechanisms of TiC0.5N0.5 Nanoparticles in Aluminum

• Published in: Materials Vol. 16; no. 3; p. 1214
• Main Authors: Wang, Kui, Jiang, Haiyan, Wang, Qudong, Wang, Yingxin
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 31.01.2023; MDPI
• Subjects: Alloys; Aluminum; Casting; Cooling; Cooling rate; Ductile-brittle transition; First principles; first-principles calculation; Grain growth; Grain refinement; Grain size; Growth models; Microstructure; nanoparticle; Nanoparticles; Nucleation; Particle size; Solids
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16031214

In this study, TiC0.5N0.5 nanoparticles (NPs) are shown to induce a remarkable grain refinement of aluminum at various cooling rates. The grain refinement mechanisms are systematically investigated by microstructure observation, edge-to-edge matching (E2EM) model prediction, and first-principles calculations. The experimental results suggest that as the cooling rates increase from 10 K/s to 70 K/s, a transition from intergranular to intragranular distribution of NPs occurs and the Al/TiC0.5N0.5 interface varies from incoherent to coherent. Based on the E2EM analysis combined with first-principles calculation, it is found that TiC0.5N0.5 can act as a potent nucleant for the heterogeneous nucleation of α-Al. By analyzing the NP effects on the nucleation and growth of α-Al, the grain growth restriction and nucleation promotion mechanisms are proposed to elucidate the refinement phenomena at low and high cooling conditions, respectively.