Titanium alloys are widely used in various industries due to their high specific strength and corrosion resistance. However, their tribological properties, such as wear resistance and friction coefficient, often require improvement for applications in conditions of intense friction and wear. Quasi-crystalline materials, especially Al–Cu–Fe-based alloys, have unique properties such as high hardness, low friction coefficient and good corrosion resistance, making them promising for use as protective coatings.
In this paper, we investigate the tribological properties of a quasicrystalline Al–Cu–Fe–Cr coating deposited by low-pressure plasma spraying on a titanium alloy. The coatings were deposited on Ti-6Al-4V titanium alloy samples. Tribological tests were performed on a ball-on-disk tribometer under various loads and sliding velocities. The structure and composition of the coatings were investigated using X-ray diffraction and scanning electron microscopy.
Using low pressure plasma spraying (LPPS) technology, a quasi-crystalline Al–Cu–Fe–Cr layer was formed on a titanium alloy. This coating is characterized by increased wear resistance and a low coefficient of friction.
The quasi-crystalline Al–Cu–Fe–Cr coating obtained by LPPS exhibits a rapidly solidifying lamella structure based on the decagonal phase with a minor presence of the cubic phase. Experimental data confirmed that the use of the quasi-crystalline Al–Cu–Fe–Cr coating significantly improves the wear resistance characteristics and reduces friction of titanium alloys in dry sliding tests. The exceptional wear resistance is due to the high hardness of the quasi-crystalline Al–Cu–Fe–Cr structure.
The results showed that the quasicrystalline Al–Cu–Fe–Cr coating had high hardness and wear resistance. The friction coefficient of the coating was significantly lower than that of the uncoated titanium alloy. The wear resistance of the coating increased with the increase of chromium content.
Quasi-crystalline Al-Cu-Fe-Cr coating deposited by low-pressure plasma spraying can significantly improve the tribological properties of titanium alloy. This coating can be used to protect titanium alloys from wear in various applications.
Author: Chungen Zhou, Fei Cai, Juan Kong, Shengkai Gong, Huibin Xu
Institute: Department of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China