| Co-Cr-W, Co-Cr-Mo and K4208alloys are frequently used in zigzag crowndamping surface wear-resisting coating materials of turbojet engine turbine rotorblade. Because of the objective reality of enhancing turbojet engine performance,they must work in an environment of high temperature, overloading and highfrequency vibration. However, the turbojet engine turbine rotor blade zigzag crownafter coating wear-resisting material appeared early failure frequently, which werebecause of the wear problems that occured in the working process. When the problemwas serious, it caused the turbojet engine turbine rotor blade zigzag crown fracture,which made a great impact to the aviation flight safety. Therefore, it is of greatsignificance of studying the friction and wear properties of these three kinds ofmaterials and contrasting analysis of their abrasion losses in high temperatures.This paper takes the wear-resisting coatings of turbojet engine turbine rotorblade zigzag crown damping surfaces as the research objects, the author ascertainedthe basic form of zigzag crown wearing, developed the MM-MS500high temperaturefretting test system which simulating the actual working conditions of turbine rotorblade zigzag crown in a turbojet engine and designed the structure drawings of thefriction and wear test components. Based on the K417nickel base of casting hightemperature alloy plates, chosed Co-Cr-W, Co-Cr-Mo and K4208alloys powders asthe raw materials, the author prepared plasma spraying Co-Cr-W, tungsten argon arcwelding Co-Cr-W, Co-Cr-Mo and K4208four different types of friction and wear testcomponents by using atmospheric plasma spraying and tungsten argon weldingtechnology.By using of MM-MS500high temperature fretting test system, it simulated thewear form of zigzag crown damping surfaces wear-resisting coating just like theywere in the working process of the turbojet engine, investigated the abrasion losses ofwear-resisting coating materials under different testing conditions. This paper studiedthe fretting abrasion losses of four different types of friction and wear test specimenunder different pressures and temperatures. By using the orthogonal experiments, itanalysed the influences of temperature and pressure to the abrasion losses of different test components. The results show that the influences of the test factors to the fourkinds of test components abrasion losses are different. They can distinguish the mainand secondary. For plasma spraying Co-Cr-W wear-resistant coating, the leverage ispressure> temperature; to argon arc welding wear-resistant coating, the leverage istemperature> pressure; for tungsten argon arc welding Co-Cr-W and K4208wear-resistant coatings, from the perspective of contributions, the leverage is stilltemperature> pressure, although both temperature and pressure have significantimpacts on the abrasion losses.This paper made the microhardness tests, the results showed that microhardnessvalues of four different wear-resisting coatings were conformed to the requirements.Observed the surface morphologies of four kinds of wear-resisting coatings beforeand after the tests, and took spectrum analysis by the method of SEM-EDS. Theresults show that except oxygen element content increased because of the oxidativewear, coating surface morphologies and other elements contents unchanged basically.Made metallographic tests, observed the sections of operative specimen coating andsubstrate binding sites, the results showed that the microstructures of the coatings andsubstrates materials didn’t change significantly after the tests.Using the method of electron beam welding and resistance spot welding, itcarried out an exploratory research about improving binding force on the plasmaspraying Co-Cr-W wear-resistant coating and K417nickel base casting hightemperature alloy substrate. The results of microstructure observation and energyspectrum analysis showed that the junction surface of the coating and substrate didn’tappear metallurgical combination, and the test failed to achieve the desired effect. |
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