Study On Friction And Wear Properties Of Copper-based Nickel Coating

In this paper,the frictional wear problem of metal matrix composites is investigated by studying the frictional wear pattern of copper-based nickel plating due to factors such as load,speed and temperature and analysing the wear mechanism generated on the surface of the plating.Pin-disk friction wear experiments,uncertainty analysis methods,finite element simulation of pin-disk experiments and microscopic morphological analysis are used to investigate the wear mechanism of nickel plating.The process of bright nickel plating was investigated through plating experiments on self-made copper-based nickel plating discs.The process of bright nickel plating was investigated in the process of making copper-based nickel plating specimens,and common problems in the nickel plating process were introduced in detail,such as pinholes in the plating,surface bonding of the plating not meeting the usage requirements,slow deposition rate,roughness and burr phenomenon on the plating surface,dark plating,orange peel-like plating,and no plating in the low current density area.The above problems can be avoided by controlling the PH,controlling the temperature and current,stirring the brightener evenly,controlling the time point and quantity of adding sodium dodecyl sulphate,and adjusting with tannic acid solution to ensure the quality of the plating.The effect of load,rotational speed and temperature on the frictional wear of copper-based nickel plating is investigated,and the wear mechanism of nickel plating is investigated using pin-disk frictional wear experiments,uncertainty analysis methods,finite element simulation of pin-disk experiments and microscopic morphological analysis.The experimental data were recorded using the loss-in-weight method.The data obtained from the experiments were combined with the response surface test design method and the uncertainty system analysis method to elucidate the interactive effects of load,rotational speed and temperature on the wear pattern of the plating through the output parameter analysis.Scanning electron microscopy(SEM),optical profilometry,X-ray energy spectrometry(EDS),optical microscopy(OM)and microhardness tester were used to analyse the surface morphology of the worn and unworn areas of the copper-based nickel plating.The worn areas have more obvious grooves,adhesion points and fallen abrasive chips on the surface of the plating.Elements such as Fe and Cr on the pins show a transfer to the surface of the plating.Microscopic morphological analysis showed that the surface of the nickel plating showed grooves along the friction direction,slightly cracked surfaces and plastic deformation.The analysis of the EDS images revealed that a new physical phase organisation had formed on the surface of the coating.The results of the uncertainty system analysis show that the load has the greatest influence on the amount of wear,followed by temperature and the smallest speed.A reasonable simplification is made according to the actual situation,and a two-dimensional static and three-dimensional sliding finite element model of the pin disc is established.The finite element simulation results show that the pressure distribution at the contact of the pin disc shows the characteristics of a small contact surface in the middle and a large edge,and the pressure distribution is not uniform.With the help of ANSYS finite element analysis software,the force state between the 45 steel pin and the nickel coated disc can be analysed visually and the friction and wear mechanism can be studied.The microscopic analysis of the wear surface shows that the main wear mechanisms on the copper-based nickel plated surface are adhesive wear,peel wear and fatigue wear,and that wear at high temperatures is mainly abrasive wear,peel wear and adhesive wear.The different types of wear can occur individually,once or several times,and in most cases it is a mixture of multiple wear mechanisms.The wear areas show grain refinement and process hardening,with a gradient in the hardness of the longitudinal section of the specimen.