Effect of laser power density on wear properties of cladding layer

Co-based layer on 40Cr steel surface was prepared by using the laser cladding technology.Macroscopic morphology of the cladding layers was observed and the microhardness was tested by using stereomicroscope and microhardness tester respectively.Based on engineering application,a dry friction and wear test with sliding and rolling mode was carried out on the laser cladded surface of 40Cr steel.The results show that: with increase of the laser power,cladding layer parameters(fusion height,fusion width,fusion depth) are increased gradually;microhardness is firstly increased and then decreased;the wear mechanism is appeared as oxidation wear-particle wear-adhesion wear-fatigue wear one by one.It is found that improving hardness of the parts is not equal to improving wear resistance.