Effect of TiC Nanoparticles Supported by Ti Powders on the Solidification Behavior and Microstructure of Pure Aluminum

• Published in: Metals and materials international 2018, 24(5), , pp.945-954
• Main Authors: Zhao, Bingyi, Cai, Qizhou, Li, Xinwei, Li, Bing, Cheng, Jingfan
• Format: Article
• Language: English
• Subjects: Aluminum; Characterization and Evaluation of Materials; Chemistry and Materials Science; Dispersion; Engineering Thermodynamics; Heat and Mass Transfer; Intermetallic compounds; Machines; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Mechanical alloying; Metallic Materials; Microstructure; Nanoparticles; Processes; Refining; Solid Mechanics; Titanium aluminides; Titanium carbide; 재료공학
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-018-0122-7

A novel grain refiner consisting of TiC nanoparticles (NPs) supported by Ti powders (abbr. TiC/Ti refiner) was prepared by high-energy milling. The addition of 0.5 wt% TiC/Ti refiner converted the structure of pure Al from coarse dendrites to fine equiaxed grains with the average grain size of 114.7 μm, and it also increased the nucleation temperature of α(Al) from 656.7 to 664.4 °C. When TiC/Ti refiner was introduced into Al melt, the heat released from the Al–Ti reaction promoted the uniform dispersion of TiC NPs. The dissolution of the reaction product TiAl 3 released Ti atoms into the melt and thus formed a “Ti-rich transition region” around TiC NPs. The dispersive TiC NPs could act as the heterogeneous nuclei for α(Al) and the “Ti-rich transition region” further improved the lattice orientation relationship between Al ( 1 ¯ 1 1 ¯ ) and TiC ( 11 1 ¯ ) planes, which eventually resulted in the refining of α(Al).