Friction And Wear Properties Of Cu-14Al-X Coating By HEPJet

The content of aluminum of Cu-14Al-X developed by our workgroup is increased to12%~16%, being adding Fe, Ni, Mn, Co and other alloying elements. The tests have shown that Cu-14Al-X possesses ideal microstructure, physical, chemical, mechanical and friction and wear properties which are all superior to conventional aluminum bronze. In order to cut the cost of Cu-14Al-X and widen its application range, we made Cu-14Al-X into powders and then coated them onto substrate, which has realized a better industrial application. In this paper, we prepared Cu-14Al-X cladding using HEPJet technology and studied its friction and wear properties. Meanwhile the friction and wear properties of HEPJet cladding were compared with that of laser and plasma cladding under the same friction condition.Microstructure of the three Cu-14Al-X claddings was analyzed by means of metallographic microscope, electron probe micro analysis, X-ray diffraction and victor hardness tester. The results show that different cladding technologies have obvious effects on microstructure, composition and hardness. Particles of HEPJet cladding present flat and are deformed sufficiently with few globular powders. pointlike K phases distribute in the cladding which is uniform, compact and with clear laminar structure. While the structure of laser cladding is the fines, the most compact and K phases dispersedly distribute. The structure of plasma cladding is bigger and more complex with dendritic and massive K phases. Content of Fe in the three claddings is the most different. The content of Fe of plasma cladding is up to 23.15%, which is 3 times as much as that of laser cladding and 5 times of HEPJet cladding. The hardness of laser cladding, HEPJet cladding and plasma cladding are respectively 380HV, 360HV and 260HV.MMW-1 was performed on friction and wear test of HEPJet cladding under dry and lubricant condition. The results show that wear form under lubricant condition is more stable. Wear mechanism under low loads (100N~420N) is abrasive wear, and with adhesive wear under 540N. Wear mechanism under dry condition is complex. Adhesive wear is main under 100N~200N, and under 300N~420N both adhesive wear and abrasive wear occur. Eventually wear mechanism changes to adhesive wear under 540N. HEPJet cladding possesses a good self-lubricant property under both dry and lubricant conditions, especially under high loads. Wear rate under lubricant condition is obviously lower and more stable with increasing loads than that under dry condition, but HEPJet cladding under both friction conditions belongs to mild wear.Friction and wear properties of HEPJet cladding were compared with that of laser and plasma cladding under the same condition. The results show that friction coefficients of laser and HEPJet cladding is stable with increasing loads and have the same changing tendency, but that of plasma cladding reduces violently which is less stable than other claddings. Wear mechanisms of the three claddings are all adhesive wear with slight abrasive wear and the higher the load is, the more severe the adhesive wear is. The three coatings possess great self-lubrication especially under high loads, for friction heat changes coatings to a perfect adhesive tribology surface. Laser and HEPJet claddings possess so high micro hardness that it can maintain mechanical property which ensures a lower wear rate. Wear rate of laser cladding is on the level of 10-10mm3kg-1mm-1 which is lower than other claddings, but they all belong to mild wear under dry condition. Wear resistance of laser cladding is the best and the most stable with increasing loads. While that of HEPJet cladding is slightly lower. Plasma cladding has the worst wear resistance and doesn't possess tribological stability.