Microstructure refinement and strengthening of Al–Cu alloys manipulated by nanocrystalline phases formed by in situ crystallization of Ni–Nb–Ti metallic glasses in melt

oleh: Tao-Tao Li, Hong-Yu Yang, Tian-Jing Miao, He-Li Peng, Xu Chen, Lin Zhu, Tao-Tao Duan, Feng Qiu, Zhi-Hao Bai, Shu-Ming Chen, Ying-Ying Liu, Xue Han, Shuang Zhang, Qi-Chuan Jiang

Format: Article
Diterbitkan: Elsevier 2020-05-01

Deskripsi

In this study, the thermal stability of Ni–Nb–Ti metallic glasses was investigated under isothermal and non-isothermal conditions. The effectiveness of NiTi phases, one of the nanosized crystallized phases, as grain refiners for Al–Cu alloys was also investigated from a crystallographic point of view using the edge-to-edge matching (E2EM) model. Thermal analysis showed that NiTi phases promote solidification of α-Al, and these nanocrystalline phases also promote an Al–Cu eutectic reaction and inhibit the growth of eutectic phases. A significant refining effect of α-Al grains from 402.7 μm to 69.1 μm was achieved with 0.05 wt.% nanocrystalline phases. Simultaneously, values for yield strength, ultimate tensile strength and fracture strain of inoculated Al–Cu alloys were increased by 18%, 13% and 78% to 363.2 MPa, 534.3 MPa and 11.92%, respectively, when compared with those of uninoculated Al–Cu alloys. Strengthening mechanisms of Al–Cu alloys manipulated by the nanocrystalline phases are grain boundary strengthening and precipitation strengthening.