A novel high-strength Al-based nanocomposite reinforced with Ti-based metallic glass nanoparticles produced by powder metallurgye

作者:Zhang, W. W.; Hu, Y.; Wang, Z.*; Yang, C.; Zhang, G. Q.; Prashanth, K. G.; Suryanarayana, C.
来源:Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2018, 734: 34-41.
DOI:10.1016/j.msea.2018.07.082

摘要

A novel Al-based composite reinforced with Ti-based metallic glass (MG) nanoparticles was fabricated by powder metallurgy through mechanical alloying combined with hot extrusion. During the ball-milling process, MG microparticles were refined into nanosized particles through severe plastic deformation. Hot extrusion of the milled powders resulted in a dense and uniform dispersion of the metallic glass nanoparticles in the Al-7075 matrix. This unique homogeneous structure led to a significant enhancement of strength without adversely affecting the plasticity, thus developing super-high specific yield strength. The yield strength increased from 297 MPa for Al-7075 matrix to 530, 610, 880, and 1014 MPa for the composites milled for 10, 15, 30, and 50 h, respectively. A critical analysis of the different factors contributing to the strength of the composites was carried out. Grain refinement, Orowan strengthening, and dislocation-dislocation interactions were demonstrated to be the most important contributors to the enhanced strength of the nanocomposite.