When a machine is in operation, two moving surfaces interact to generate a large amount of wear particles. The wear debris generated inside the machine or contaminants from outside plays important roles in both two-body and three-body wear. For all mining and port machinery, their lubricants are very likely to be polluted by contaminants such as silica and other metallic debris such as iron and nickel. In order to seek a deeper understanding of the effects of different contaminants on wear process, this project investigated sliding wear processes when silica powder and iron powder exist in lubricants. Four sliding wear tests were conducted on a pin-on-disc tester with and without the contaminants. Visual inspection, ferrography analysis, particle quantity analysis using a particle analyzer, and numerical surface analysis using confocal laser scanning microscopy (CLSM) were conducted to study the wear particles and wear surfaces. Supported by the data generated from the comprehensive analyses on the wear particles and wear surfaces, the investigation of the effects of the added contaminants to the wear processes and wear mechanisms have been carried out and presented in this paper.

Fractals can be extremely useful when applied to tribology. Obtaining fractal descriptions of engineering surfaces and wear particles requires surface topography information to be measured, digitized and processed. Such procedures can be rigorous. This article compares various methods to calculate profile and surface fractal dimension. Profile fractal dimension is computed using three available methods, corresponding to the yard-stick, the power spectrum and the structure function method. The precision of the three methods is analyzed and compared in this paper. Surface fractal dimension is calculated using the slit island and the box counting method. Both profile fractal dimension and surface fractal dimension are used to describe TiN coating surfaces and wear particles.

Six sliding wear tests have been conducted using a pin-on-disc tester to investigate the effects of temperature on sliding wear processes when the iron particle contaminants were existent or non-existent in the SAE40 lubricant. Ferrography analysis, particle size analysis using a CSI particle analyzer, numerical analysis on particle morphology based on confocal laser scanning microscope (CLSM) and surface examination of the tested samples using scanning electron microscope (SEM) were used to study the wear particles and the wear surfaces. Supported by data generated from the comprehensive analyses of the wear particles and the surfaces of the tested samples, it is clear that the temperature of the SAE40 lubricating oil has a significant influence on the wear processes. The increase in the temperature of the SAE40 lubricant increases the probability of adhesion, oxidation and wear rates. For the tests at elevated temperature, when the iron particles are added into the SAE40 lubricant, the degree of oxidation wear increases compared with the test without the iron particles in the SAE40 lubricant. This study has shown that temperature plays an important role in wear process and it is crucial to control temperature for controlling wear rates in sliding wear process.

The lubricated rolling wear was simulated using a specially modified pin-on-disctester. Wear particles were collected in running-in and steady state wear stage, and analysed using a particle analyser, ferrography, confocal laser scanning microscopy and computer image analysis techniques. Numerical parameters, Ra, Rq and Rsk were used to measure the evolutions of the surface alternations from the running-in to steady state wear stage. Quantitative data on the evolutions of the surfaces of both the wear debris and the wear components were presented in the paper. The knowledge obtained in this research is important for predicting wear conditions using wear debris analysis techniques, while further understanding of the wear mechanisms and wear characteristics has been also gained.

从腐蚀极化曲线测试的特点及要求出发，用微机和普通恒电位仪组成其测试系统，由计算机通过D/A转换产生所需的波形电压，代替波形发生器工作，然后用两路A/D分别采集腐蚀电流和腐蚀电位，并同步显示腐蚀极化曲线。本研究在提高腐蚀极化曲线测试水平方面作出了成功的尝试。