Experimental Study On Laser Cladding Strengthening Of The Surface Of Deep Loose Shovel Tip

The subsoiling shovels are the main components of the agricultural machine cultivation operation.During the operation,the subsoiling shovels are strongly impacted by soil,sand,plant roots and other strong friction and wear due to the impact of large force,so that the subsoiling shovels wear fast.It can not only affect the efficiency and effectiveness of the operation,but also causes certain economic losses.At present,there are few researches on the surface wear resistance of agricultural machinery parts.This paper uses advanced laser cladding technology to weld a alloy materials surface with high performance on wear resistance which mainly contain nickel powder on the surface of subsoiling shovels to improve the service life.In this paper,65Mn steel,which is commonly used in the contact parts of agricultural machinery,is chosen as the base material.Dry nickel-based alloy powder is used to form a wear-resistant layer of nickel-based alloy by metallurgical combination with high-energy laser irradiation.The effects of laser power,scanning speed and defocusing amount on the structure and wear resistance of Ni-based alloy cladding layer were discussed.The three parameters in the experiment were optimized by orthogonal experiment with the friction and wear resistance of the cladding layer as the index.The metallographic microscope,Vickers hardness tester and XRD were used.The microstructure,phase,hardness of cross section and friction and wear properties of laser cladding layer were analyzed by means of diffractometer,scanning electron microscopy and friction and wear test bench.Finally,the following conclusions are drawn from the field experiment:?1?The orthogonal experiment shows that the order of the three parameters affecting the wear resistance of the cladding layer is defocusing quantity>scanning speed>laser power.The optimum combination of the three parameters is laser power:6000W,defocusing quantity370mm and scanning speed 550 mm/min.?2?Scanning section of scanning electron microscopy shows that the metallurgical bonding is good,the bonding structure is compact and uniform,and there are no defects such as pore and crack.The hardness of the nickel-based alloy cladding layer reaches 856.5 HV_0.1,which is higher than that of 65Mn steel,280 HV_0.1.The phases of the cladding layer are CrB,M₇C₃,M₂₃C₆ and Ni₃Si.Field experiments show that the friction and wear properties of the cladding Subsoiling shovels of agricultural machinery are significantly improved by optimizing the orthogonal experimental parameters.Experiments show that the friction and wear properties of the cladding Subsoiling shovels of agricultural machinery are significantly improved compared with other Subsoiling shovels,and the cladding has higher economic benefits.