时间 : 2024年05月21日 09时30分
地点 : A校区理科楼010教室
主讲人 : Prof. Elena Torskaya
High-strength aluminum alloys, in particular AlZn5.5MgCu, are widely used due to their low density and low cost. Their tribological properties are poor, so surface modification is required, one of which is plasma electrolytic oxidation (PEO). This study proposes a new type of modified PEO coatings, during the formation of which nanodiamonds (ND) and micro dispersed silver were added to electrolyte in different concentrations. A comprehensive method for studying coatings included friction and wear tests at room and elevated temperatures (100℃ and 200℃), elastic indentation with original method for processing the results, studying friction tracks and sections of samples using microscopy methods, and calculating stresses in coated bodies. It was obtained that wear of the modified coatings is only roughness smoothing. The failure of coatings with and without modifiers takes place through the mechanism of brittle fracture. The higher the test temperature, the more modifiers must be used to avoid the fracture, as well as to ensure a stable coefficient of friction. Samples with the largest volume of modifiers (9g/l ND + 9g/lAg in basic electrolyte) had COF in the range of 0.34-0.37 at all temperatures.