A Research Of Impact Of Mechanical Performance Of Low Hardness Dust Particles On Electrical Contact

There is serious dust pollution in China, and dust particles have become an important factor in electrical contact failure which may cause wear and corrosion on contact surfaces and lead to a significant impact.The main low hardness particles in the air are Calcite and Muscovite. In this paper, studies of Calcite and Muscovite particles with small size (1000μm or less) are performed. Special analyze methods are designed to locate and study these particles. The analyses are carried out in two aspects, and they are static state contact resistance experiments and fretting contact resistance experiments. The purpose of this paper is to identify the index of the mechanical performance of low hardness dust particles on electrical contact failure.In static state experiment, first step is to find out the failure modes of single particle and a cluster of particles in suspension loads. This part can be the basis for the research of the corresponding relationship between the particle sizes before and after it is broken. In addition, it prepares for the further fretting test. Then a series of research shows the detail relationship between particle sizes and the suspension load. In the end, this paper presents the impact of particle sizes that may easily cause failure, and figures out the reasonable loads that can efficiently reduce the impact with particles in the contact areas.In the fretting testing research, the contact performance between the probe and sample are determined without low hardness dust particles in the contact areas. Then using different loads and particle sizes, a series of experiments are done to test the fretting performance. Compared with the results of low hardness dust particles existed or not existed in contact area, it can be conclude that the impact of load and particle size in fretting mode. In addition, with the help of fluorescence thickness measurement and SEM, further researches have been done to test the wear performance when there are low hardness dust particles in the contact areas.In conclusion, this paper illuminates the failure modes of low hardness dust particles through the research of contact loads and particle sizes through static and fretting researches. And it also evaluates the main mechanical performance of low hardness dust particles that may cause electrical contact failure.