Quasi-crystalline alloys, characterized by a unique combination of high hardness, corrosion resistance and low friction coefficient, are promising materials for the creation of wear-resistant coatings. The introduction of additives such as tin (Sn) into quasi-crystalline matrices can change the tribological properties of coatings, optimizing them for specific applications. The plasma spraying method allows the formation of coatings with high adhesion and density.
Composite coatings of Al–Cu–Fe + Sn were applied to a steel substrate by plasma spraying. The tin content varied within 5–15 wt.%. Tribological tests were carried out under dry sliding friction conditions using the “ball-on-disk” scheme at various loads and sliding speeds. The microstructure and phase composition of the coatings were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD).
The introduction of tin into the quasicrystalline Al–Cu–Fe matrix changes the microstructure and phase composition of the coatings. SEM shows the formation of a finely dispersed structure with a uniform distribution of tin. XRD confirms the presence of a quasicrystalline phase and a tin phase. Tribological tests have shown that the addition of tin reduces the friction coefficient and wear rate of the coatings. The optimum tin content is about 10 wt.%. The decrease in the friction coefficient is explained by the formation of an oxide film on the friction surface, which has a lubricating effect.
In this paper, we plan to demonstrate the results of studying the effect of a soft component on the tribological characteristics of Al–Cu–Fe composite coatings. Composite powders with different tin contents (from 0% to 30% by volume) were produced by gas spraying before being applied to medium-carbon steel substrates by air plasma spraying. The friction and wear of the composite coatings were studied in a dry air environment using a ball-on-disk tribometer in the reciprocating motion mode. The results of the experimental studies indicated that the introduction of 20% tin by volume led to a decrease in wear due to an increase in the resistance of the composite coatings to crack propagation.
Composite coatings Al–Cu–Fe + Sn obtained by plasma spraying have improved tribological properties compared to pure quasicrystalline coatings Al–Cu–Fe. The addition of tin allows optimizing the friction coefficient and wear rate, which makes these coatings promising for use in dry sliding friction conditions.
Author: Tianmin Shao, Xiankun Cao, Eric Fleury, Do-Hyang Kim, Meng Hua, Dao Se
Institute: State Key Laboratory of Tribology, Tsinghua University, Building 9003, Beijing, 100084, People’s Republic of China, Center for Non-Crystalline Materials, Yonsei University, Seoul, South Korea, Faculty of MEEM, City University of Hong Kong, People’s Republic of China