Research On Effects Of The Second Phase Particle Size On The Properties Of AgSnO₂ Electrical Contact Materials

The electrical contact failure,which mainly caused by electrical contacts failure,brings about the seventy percent of invalid electrical appliances.AgSnO₂ electrical contact material is a new kind of environmental protection electrical contact material with wide application prospects.Which still exists some deficiencies,such as large contact resistance,excessive temperature rise,great hardness and difficulties in machine shaping.This is mainly due to the high hardness and poor electrical conductivity of SnO₂,which leads to larger resistance value and higher hardness of the composite material.The selection of powder size of SnO₂,a main component of AgSnO₂ electrical contact materials,is the key step in the preparation of electrical contact materials,which plays an important part in the property of the electrical contact property of AgSnO₂ electrical contact material.Therefore,the effect of the second phase SnO₂ particle size on the performance of AgSnO₂ electrical contact material is mainly discussed.Improving the physical performance and electrical contact performance of the AgSnO₂ electrical contact materials is of important in theoretical significance and practical application value.Firstly,in this paper,combining the relevant knowledge of electrical contact theory and the progress of studies on electrical contact industry in recent yeas,six different second-phase particle size values are identified.Different electrical contact materials including undoped AgSnO₂,AgSnO₂/CuO,AgSnO₂/Bi₂O₃,AgSnO₂/La₂O₃,are prepared by powder metallurgy method under different conditions of particle size.Secondly,according to the basic performance testing methods of GB/T5586-2016electrical contact material,the electrical conductivity,density and hardness of the electrical contact material is measured.Then the impact caused by the second phase particle size on the physical properties of AgSnO₂ electrical contact materials is discussed.By using the testing system of JF04C electrical contact materials,electrical contact performance test was conducted on the electrical contact material,which obtaining the contact resistance,arc energy,arc time and welding force parameter.And the effects of the second phase particle size influence on the contact AgSnO₂ electrical contact material are analysed.In the end,adopting the fuzzy comprehensive evaluation theory to analyzes the test data.Based on the improved analytic hierarchy process and entropy method,the combination weight of each evaluation index is determined.As a result,the effect of second phase particle size on AgSnO₂ electrical contact material properties is comprehensively judged.Optimum value of second phase particle size of four kinds of electrical contact materials,which include undoped AgSnO₂,AgSnO₂/CuO,AgSnO₂/Bi₂O₃,AgSnO₂/La₂O₃can be selected according to the results of experiment and assessment.As a result,the physical performance and contact performance of the AgSnO₂ electrical contact material are improved to a great extent.