Advanced wear protection at high temperatures: A study of Al20V20Cr20Nb(40-x)Mox RHEA coatings on Ti6Al4V by laser cladding

• Published in: Applied surface science 2024-11, Vol.673, p.160878, Article 160878
• Main Authors: Liu, Hao, Huang, Can, Tu, Jian, Huang, Haozhen, Luo, Jinwei, Fang, Suiyuan, Peng, Shuoshu, Wang, Hanguang, Yang, Ling, Chang, Xia, Duan, Huming
• Format: Article
• Language: English
• Subjects: High-temperature tribology; Laser cladding; RHEAs; Ti6Al4V
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.160878

[Display omitted] •Successful fabrication of single BCC low-density Al20V20Cr20Nb(40-x)Mox refractory high entropy alloys on TC4 substrates.•The wear rate of Mo30 coating at 600 °C is 1.769 × 10-6mm3⋅N−1⋅m−1, a reduction of 98.35 % as compared to 107.213 × 10-6mm3⋅N−1⋅m−1 of TC4.•The dense oxide film plays an important role in high temperature wear, and the abrasive particles can effectively reduce the friction contact with the alloys effectively reducing the coefficient of friction.•Rod-like Al2(MoO4)3 and Cr2(MoO4)3 enhance the stability of the oxide film at high temperatures. Al20V20Cr20Nb(40-x)Mox Refractory High Entropy Alloys (RHEAs) coatings were applied to Ti6Al4V surfaces via laser cladding. These coatings, primarily in a single BCC phase with dendritic microstructures, demonstrated varied wear resistance. Notably, the Al20V20Cr20Nb10Mo30 exhibited the highest wear resistance, achieving a wear rate reduction of 98.35 % and 99.28 % compared to uncoated Ti6Al4V and the Al20V20Cr20Nb30Mo10 coating, respectively. This superior performance is attributed to the formation of a dense oxide film and the beneficial presence of rod-like Al2(MoO4)3 and Cr2(MoO4)3 oxides, which enhance mechanical clamping at the surface. The study highlights the critical role of rapid oxide film formation at 600 °C in enhancing the high-temperature wear resistance of Ti6Al4V, offering insights into the tribological behaviour of RHEA coatings under extreme conditions.