Study On The Friction And Wear Of Copper And Aluminum Pseudo-alloy

The pseudo-alloy is to use two or more metals exist in independent and uniform phase,each do not form alloy phase is a kind of metal matrix composites. Electric arc spraying technology has the characteristics of high production efficiency, the coating performance, the economy and energy saving, large area construction, safety and to the preparation of pseudo alloy coatings. Current study of pseudo alloy is growing, but mainly concentrated in the zinc aluminum pseudo-alloy and magnesium aluminum pseudo-alloy corrosion resistance research,especially the zinc aluminum pseudo-alloy in the Marine steel structures, Bridges, ships,tower need anti-corrosion occasions such as widely used. And the study of copper aluminum pseudo alloy were very small, only around the coating microstructure and morphology, group composition after heat treatment, hardness measurement and tensile bond strength are analyzed. In the substrate after spraying copper aluminum pseudo-alloy friction performance study hardly.This topic uses arc spraying method on HT250 substrate spraying copper aluminum pseudo-alloy coatings, and compared with 40 CrNiMo for the formation of sliding friction pair,in the M- 2000 wear testing machine for dry friction and oil lubrication two kinds of working conditions of sliding friction and wear experiments, and the matrix and friction coefficient,wear rate and the wear mechanism of the coating are analyzed.The experimental results show that:(1) under the condition of dry friction, with the increase of load, the coefficient of friction of HT250 and copper aluminum pseudo-alloy coating specimen is the biggest of all in the initial stage, after gradually reduce the trend, into the stable wear stage of the instantaneous friction coefficient also increases gradually. With the increase of load, HT250 specimen smaller period of time in the steady stage of wear, but the time for copper aluminum pseudo-alloy coating into stable wear stage has small impact.(2)under the condition of oil lubrication, with the increase of load, the coefficient of friction of HT250 and copper aluminum pseudo-alloy coating specimen at the initial stage is the largest in the mass, after gradually reduce the trend, into the stable wear stage, the instantaneous friction coefficient also increases gradually, but small.HT250 specimens respectively in the revolutions of 3200 turn, 800 turn, 1600 turn, 7200 turn, 5600 turn by the running-in stage into the stable wear stage, This suggests that HT250 matrix into stable wear stage the time range is 2-18 minutes, but the increase of the load for the time of copper aluminum pseudo-alloy coating into the steady stage of wear has small impact.(3) Under different working conditions, the average coefficient of friction of HT250 and copperaluminum pseudo-alloy coating specimens were increased with the increase of load increase,when the load is increased from 100 n to 200 n friction coefficient increased most significantly,followed with the increase of load increase of friction coefficient tends to weaken. Under the condition of dry friction, the average friction coefficient of copper aluminum pseudo-alloy coating specimens is lower than the average friction coefficient of the HT250 substrate specimens, under the condition of oil lubrication, the average friction coefficient of copper aluminum pseudo-alloy coating specimens is higher than the average friction coefficient of the HT250 substrate specimens. Under the same load, the HT250 substrate specimens under dry friction condition have the highest average friction coefficient, the HT250 substrate specimens under the lubrication condition have the minimum average friction coefficient. Can be determined under the condition of dry friction copper aluminum pseudo-alloy coating specimens have small friction coefficient and their surface friction performance is better than HT250 specimens; Under the condition of oil lubrication, HT250 substrate specimens have smaller friction coefficient, and the surface friction performance is better than copper aluminum pseudo-alloy coating specimen. Test shows that spraying copper aluminum pseudo-alloy coatings on HT250 substrate can improve the surface friction performance of the material under the condition of dry friction.On the basis of experiment, the sliding wear mechanism of HT250 and copper aluminum pseudo alloy coatings in the dry friction and lubrication of two different working conditions was studied:(1) under dry friction and lubrication conditions, the wear volume of HT250 specimen and copper aluminum pseudo-alloy coating specimen is increased with the increase of load.Two kinds of working conditions, under low load condition the wear volume of copper aluminum pseudo-alloy coating is smaller than HT250 substrate, under the condition of high load is bigger than HT250 substrate. Under the condition of dry friction the wear volume of copper aluminum pseudo-alloy is the largest. Under the condition of oil lubrication,the wear volume of HT250 specimen is the smallest. This suggests that spraying copper aluminum pseudo-alloy coatings on HT250 substrate can improve the wear ability of HT200 materials only under low load condition.(2) under the condition of dry friction, the wear mechanism of HT250 are mainly abrasive wear and the wear mechanism of copper aluminum pseudo-alloy coating at low load are mainly abrasive wear and at high load(300n) are mainly adhesive wear;Under the condition of oil lubrication, the wear mechanism of HT250 under low load are mainly abrasive wear and wear mechanism under high load(300n) are mainly adhesive wear; the wear mechanism of copper aluminum pseudo-alloy coating is mainly abrasive wear;(3) orthogonal analysis method of sliding experiment data are analyzed, and the coefficient of friction and wear rate, factors that determine the best combination of various levels.