Study of the tribological behavior of the Babbitt alloy – steel ABNT 1045 pair when varied thickness and roughness of the coating

ABSTRACT Babbitt, also known as patent metal or white metal, is a soft alloy widely used in sliding bearings that work in contact with steel, and has as base elements tin or lead, as well as intermetallic compounds usually formed by antimony and copper. The aim of this work was to evaluate the influence of the parameters roughness and thickness of the coating on the tribological behavior of the alloy when in contact with steel ABNT 1045. Tribological pin-on-disk tests were performed using ABNT 1045 steel pins and Babbitt-coated steel test specimens simulating the contact of a shaft on a Babbitt-coated bearing. The roughness and the thickness of the coating were varied in three levels, in order to observe the behavior in relation to the friction and the wear with the modification of these variables. In the tests that used test specimens with the smallest roughness within the analyzed range, an increase of 0.05 ± 0.02 to 0.46 ± 0.06 in the friction coefficient occurred when the coating thickness was raised from 0.45 ± 0.07 mm for 1.08 ± 0.17 mm. The highest coefficient of friction was observed in the test of the specimen with a higher coating thickness (1.08 ± 0.17 mm) and lower roughness (0.47 ± 0.01 μm), the highest wear was recorded in the test with the highest coating thickness and roughness (1.08 ± 0.17 mm and 1.29 ± 0.20 mm, respectively) and the lowest wear and friction coefficient were obtained by the test performed in the specimen with the least roughness (0.43 ± 0.03 μm) and medium coating thickness (0.45 ± 0.07 mm).

摘要：巴氏合金（Babbitt），又称专利合金或白合金，是一类广泛应用于与钢材接触工况的软质滑动轴承合金，其基体组元为锡或铅，通常还含有由锑与铜构成的金属间化合物。本研究旨在评估涂层粗糙度与涂层厚度参数，在巴氏合金与ABNT 1045钢接触时，对该合金摩擦学性能的影响。试验采用销盘摩擦磨损方案，以ABNT 1045钢销作为摩擦副，搭配镀覆巴氏合金的钢试样，模拟轴与巴氏合金轴承的接触工况。本次试验将涂层粗糙度与涂层厚度各设置三个梯度，以探究这两项变量改变时，合金的摩擦与磨损特性变化规律。在采用分析范围内粗糙度最低的试样开展的试验中，当涂层厚度从0.45±0.07 mm提升至1.08±0.17 mm时，摩擦系数由0.05±0.02升高至0.46±0.06。摩擦系数最高的试验结果来自涂层厚度最大（1.08±0.17 mm）且粗糙度最低（0.47±0.01 μm）的试样；磨损量最高的试验则出现在涂层厚度与粗糙度均取最大值的工况下（分别为1.08±0.17 mm与1.29±0.20 μm）；而磨损量与摩擦系数均最低的试验结果，则来自粗糙度最低（0.43±0.03 μm）且涂层厚度为中等水平（0.45±0.07 mm）的试样。