Influence of Debris Size on the Tribological Performance of Flame-Sprayed Coatings

Due to the increased contact pressure and abrasive action on the coated surface, larger debris particles can result in higher wear rates. When designing and applying flame spray coatings in various industrial environments, it is important to consider how debris size affects the frictional performance of the coatings. This work aims to assess debris particle size's effect on Ni-based alloy coating's tribological properties. This is a key manufacturing issue that can help prolong the life of devices and provide proper maintenance. Debris is rated as Al2O3 solid particles, where their size ranges from 1.5 ± 0.03 µm to 42 ± 0.03 μm, dispersed in an oil lubricant. The coatings are characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM), while the cross-sectional evaluation is analyzed utilizing X-ray Diffraction (XRD). The coating is sprayed with NiCrBSi and melted in a flame. Hardened F-5220 metal forms a counter disk (according to ASTM A681). Our findings demonstrate that the alumina particles cause wear to increase significantly, particularly for bigger particles. When it comes to micrometer-sized particles, an increase in volume loss is seen as a result of increased surface roughness, plenteous microgrooves, and plastic flow of the NiCrBSi coating vertically to the sliding orientation. In addition, it has been proven that the nanosized particles play a secondary role in a tribological system in contrast to microparticles. Debris measurement is quantitatively related to friction and lubrication adjustments. Surface roughness can be assessed as a characteristic of the particle size. Large particles cause excessive induce high coefficient of friction at NiCrBSi coatings.