Inconel 718+La2O3的高温摩擦磨损行为研究OA

To enhance the high-temperature wear resistance of Inconel 718 alloy,Inconel 718 composite cladding layers with different La2O3 contents[0％、0.4％、0.7％、1.0％、2.0％(mass fraction,the same below)]were fabricated on 45 steel substrate using laser-directed energy deposition(LDED)technology.The effects of La2O3 content on the microstructure,microhardness,and friction and wear behavior at 700℃ were systematically investigated.The results show that the addition of an appropriate amount of La2O3 significantly refined the grains,reduced defects such as pores and microcracks,and improved the compactness and microhardness of the coatings.Among them,the C3 coating with 1.0％La2O3 exhibited the optimal comprehensive performance.Its average microhardness increased by approximately 9.2％compared to the coating without La2O3,and it demonstrated the lowest friction coefficient of 0.09 and the most intact wear surface at 700 ℃,accompanied by the formation of a continuous and dense oxide layer.Insufficient or excessive La2O3 content led to the deterioration of coating microstructure and aggravated adhesive wear.The mechanism analysis reveals that the rare earth oxide La2O3 synergistically improves the high-temperature wear resistance of the Inconel 718 cladding layer through multiple mechanisms,including grain refinement strengthening,grain boundary purification,and promoting the formation of a dense oxide layer which acts as lubrication and protection.