Study On Process Of Contact Material PtIr25 For Aeroengine

PtIr25 alloy, as electrial material, is widely used in aviation and aerospace field because of its comprehensive properties. But at present there are some problems in production of PtIr25 alloy in our courtry, Such as composition segregtion;poor processability ; unstable performace of electrial material.In this paper,by means improving traditional process, PtIr25 alloy with excellent and stable properties were produced.On improving process aspect, component homogeneity of PtIr25 wered greatly improved by medium-frequency and high-frequency melting and heat-treatment technology;Processability was improved by hot rolling technology;The hardness and the properties stability of PtIr25 were improved by age-hardening. The microstructure, physical property,mechanical property and electrical property of of PtIr25 was tested and studied, by meaning of metallurgical microscope , microhangness tester of the MH-6, tensile testing machine of the MTS858. The contact electrical property of PtIr25 was simulated by ASTM under practical application condiction. The ability of arc erosion and welding resistance was tested by the strengthen test equipment of electric properties. The properties of PtIr25 was compared with Pt. The ability of contact resistance, antioxidation and corrosion resistance was also studied.The results show that: The process for PtIr25 is suitable in this paper,the sheet of PtIr25 alloy meeting the requirements of electrical contact materials of aeroengine. In alloy the content deviation of Pt and Ir no more than 0.5%;The single reduction reached 10% and The total reduction reached 70% by heat treatment process and hot rolling process; The hardness was obviously improved by the age-hardening. It was improved from 280～290 to 320～335 by quenching at 1500℃～1700℃and tempering at 800℃for 30 minutes;The electrical properties of PtIr25 was improved and its electric resistivity is low by improving melting process and heat treatment process.Its electric resistivity is 0.34～0.37μ?.m;Welding resistance and arc ablation of PtIr25 is excellent. PtIr25 meet the requirement of ten million tests. The arc energy of PtIr25 is low and its change tendency is stable.The ability of antioxidation and corrosion resistance is excellent.