中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 5 May 2020 |
（1. School of Energy, Power and Mechanical Engineering, North China Electric Power University, Baoding 071003, China;
2. College of Mechanical and Electric Engineering, Hebei Agricultural University, Baoding 071001, China）
Abstract:The influence of Al addition on the microstructure of Cu-B alloys and Cu-ZrB2 composites was investigated using scanning electron microscopy, X-ray diffraction and first-principles calculation. The results show that the eutectic B in Cu-B alloys can be modified by Al from coarse needles to fine fibrous structure and primary B will form in hypoeutectic Cu-B alloys. As for Cu-ZrB2 composites, Al can significantly refine and modify the morphology of ZrB2 as well as improve its distribution, which should be due to its selective adsorption on ZrB2 surfaces. The first-principles calculation results indicate that Al is preferentially adsobed on ZrB2 (1210), then on ZrB2 (1010), and finally on ZrB2 (0001). As a result, smaller sized ZrB2 with a polyhedron-like, even nearly sphere-like morphology, can form. Due to Al addition, the hardness of Cu-ZrB2 composites is greatly enhanced, but the electrical conductivity of the composites is seriously reduced.
Key words: Cu-B alloys; Cu matrix composites; modification effect; microstructures
