Preparation And Performance Study Of AgSnO₂ Electrical Contact Material

As the European union and Japan have made relevant policies to prohibit or restrict the use about containing Cadmium materials.Silver Cadmium Oxide considered as universal electrical contact exit the electrical contact field gradually.Due to AgSnO₂ have excellent antiarc erosion properties and anti-welding properties,it becomes a most potential substitute contact material for AgCdO.But with the application and research to AgSnO₂,more and more researcher find that AgSnO₂ contact materials have the problem of low workability,high contact resistance,high temperature rise and low electrical life in AC3.These defects seriously affect the electrical performance and the main reason is that SnO₂partical is too big and have a bad dispersion and wetting properties.Domestic and abroad researcher think that method and additive is the most important to material's workability and electrical performance.So the thesis have researched from preparing method and additives.In the aspect of material preparation,we use alloy oxidization method?AOM?,powder oxidization method?POM?and hydrothermal plating method?TPM?to prepare AgSnO₂electrical contact material,and get the following results.?1?By means of researching for internal oxidation mechanism,oxidizing condition and processing method,obtain that processing method is an important aspect to material's workability.?2?By means of XRD,SEM and TG analysis for POM powder,we research the effect of temperature,pressure to powder oxidation and get the best oxidizing parameters with oxidizing pressure0.5-1.0 bar,oxidizing temperature 700?12 h.?3?By means of hydrothermal and chemical plating for Sn²⁺,get nano SnO₂ partical and homogeneous AgSnO₂ powder.Besides,we also research the effect of hydrothermal condition,annealing temperature to AgSnO₂powder.In the aspect of additives,AgSnO₂ electrical contact material doping NiO,TeO₂,CuO,In₂O₃ were prepared by POM.Compared with no additives,doping AgSnO₂ material have better hardness,density,tensile strength,low elongation,material transfer resistence,high welding resistance,wettability and electrical life.At the same time,it also increase the contact resistance.At last,three method products are tested by Doduco relay model switch system.And we obtain the different electrical performance about three method.