中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 31 No. 9 September 2021 |
（1. School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China;
2. School of Mechanical Engineering, Changzhou University, Changzhou 213164, China;
3. Meltron Metal Surface Technology (Changzhou) Co., Ltd., Changzhou 213164, China）
Abstract:In order to improve the hardness and tribological performance of Ti6Al4V alloy, NiCoCrAlY–B4C composite coatings with B4C of 5%, 10% and 15% (mass fraction) were fabricated on its surface by laser cladding (LC). The morphologies, chemical compositions and phases of obtained coatings were analyzed using scanning electronic microscope (SEM), energy dispersive spectrometer (EDS), and X-ray diffraction (XRD), respectively. The effects of B4C mass fraction on the coefficient of friction (COF) and wear rate of NiCoCrAlY–B4C coatings were investigated using a ball-on-disc wear tester. The results show that the NiCoCrAlY–B4C coatings with different B4C mass fractions are mainly composed of NiTi, NiTi2, α-Ti, CoO, AlB2, TiC, TiB and TiB2 phases. The COFs and wear rates of NiCoCrAlY–B4C coatings decrease with the increase of B4C content, which are contributed to the improvement of coating hardness by the B4C addition. The wear mechanisms of NiCoCrAlY–B4C coatings are changed from adhesive wear and oxidation wear to fatigue wear with the increase of B4C content.
Key words: Ti6Al4V alloy; laser cladding; NiCoCrAlY coating; B4C; tribological behavior; wear
