| With the development of science and technology,industry has put forward higher requirements for the properties of materials.Therefore,composite materials with various excellent properties came into being,which has promoted the development of materials to a certain extent.Aiming at the problems such as warping deformation,abnormal wear and shedding caused by insufficient adhesion stability of the friction layer of the traditional sintered and pressed clutch friction plate,this paper adopts the laser cladding rapid prototyping process manufacturing method to fuse the copperbased powder metallurgy friction material.The preparation of cladding,and the SEM electron microscope performance test for the friction material cladding test piece was carried out to analyze the dilution rate of the cladding layer;the finite element model of the laser cladding was established,the numerical simulation of the temperature field was performed,and the temperature field was analyzed.The dynamic characteristics and variation rules of the temperature field in the molten pool and the influence of process parameters on the temperature field are analyzed in detail;The numerical model of friction torque is established,and its characteristics are simulated and analyzed.The accuracy of friction performance and wear test results verified the correctness of the simulation.The above research results show that the laser cladding rapid prototyping process of copper-based metallurgical friction materials significantly improves the distribution of various components in traditional sintering and pressing,and the carbon atoms are more closely combined with the metal powder,and there are no obvious cracks on the surface.The copper-based alloy material of Ni276 self-fluxing powder improves the compatibility of carbon atoms in the alloy molten pool,reduces the melting speed of graphite in the high temperature molten pool,improves the wear resistance of the cladding layer,and makes the friction material and the substrate material achieves true metallurgical bonding,which effectively reduces the possibility of friction material falling off under extreme working conditions.Through the simulation of the temperature field of laser cladding,it can be seen that under the laser cladding molding process,the temperature curve of each node in the middle of the molten pool along the penetration direction is basically the same,the temperature curve of each node in the center of the molten pool along the direction of penetration is basically the same,the peak temperature decreases with the increase of penetration direction,and the temperature gradient of the molten pool and cooling the speed decreases with the increase of the distance from the surface of the cladding layer.Taking the powder melting and dilution rate as the quantitative standard,the optimal process parameters for this cladding material are laser power P=1800 W,laser scanning speed v=10 mm/s.The friction characteristics of the friction materials prepared by the laser cladding molding process were studied.The simulation and experimental tests showed that when the relative rotational speed was less than 1500 r/min,the sliding friction work was only related to the rotational speed value,which was basically a linear distribution relationship,and was affected by a linear distribution.The influence of the pressure parameters is small,and the maximum difference of the sliding friction work under the axial pressure of 0.6MPa and 1.2MPa is about 0.07% of the average value.When the relative rotational speed of the friction pair exceeds 1500 r/min,the sliding friction power is also affected by the pressure parameters,which increases with the increase of pressure;when the relative rotational speed is about 2300 r/min,the sliding friction under 1.2 MPa axial pressure Compared with the sliding friction work under 0.6MPa axial pressure,the work is increased by 18%. |
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