Reasearch On Resin System Design And Friction And Wear Performance Of EP/KF Composite Materials In Seawater Environment

This paper aims to study friction and wear properties of epoxy resins and Kevlarfiber reinforced epoxy composites under salt water lubricating and dry slidingconditions against Tin Bronze thrust ring. In order to further understand wearmechanisms, worn surfaces were analyzed by scanning electron microscopy (SEM) andX-ray photoelectron spectroscopy (XPS).TED-85and615epoxy resins were chosen as matrix and molybdenum disulfide,graphite and antimony sulfide play roles as fillers in this epoxy resin system. After sometests of DTA, cure process was confirmed and many resin casting test specimens ofsingle filler but different proportions were made. A lot of work was done includinganalyzing friction mechanism, evaluating friction and wear performance influencecaused by sea water corrosion, measuring samples moisture absorption rate, measuringchanges of Barcol Hardness value of samples, measuring changes of polymer bodystructure and phase transformation of sample surfaces, and so on. All the workmentioned above helps to choose appropriate epoxy resin system of EP/KF compositematerials and understand wear mechanisms of EP/KF composites under both salt waterlubricating and dry sliding conditions against Tin Bronze thrust ring.Fillers of molybdenum disulfide and antimony sulfide didn’t play roles in the drysliding condition. Lubrication effect did not exist. Another filler-graphite coulddramatically reduce the resin casting samples’ friction coefficient under salt waterlubricating condition, but fluctuation of friction coefficient was large. Adding too muchthree kinds of fillers would influence whole resin systems’ curing effect and uniformity.After soaking in seawater, Barcol Hardness values of resin casting specimens lessen.Ir-spectra and XRD showed that there were no changes, after soaking in seawater,on chemical composition, whether insides of samples or surfaces of samples. Thistesting resin system presented a good corrosion resistant to salt water. But frictioncoefficient presented a big fluctuation phenomenon. XPS and SEM showed that underdry sliding condition, sample friction surfaces already embedded by grinded metal atom,and their damage was more serious than that under salt water lubricating condition.Three strands of twisting Kevlar fiber promoted mechanical strength of resinmatrix. In friction process, Kevlar fiber assumed most loads, and promoted the materialwear-resisting performance. Under salt water lubricating condition, with increase ofloads, friction coefficient of EP/KF composite specimens tended to be stable. But underdry sliding condition, friction coefficient tended to increase after the first. Under two conditions, wear was both increasing with increase of loads. Under Salt waterlubricating condition, wear was reduced. Wear mechanism of dry sliding includedgelling wear, abrasive wear, fatigue wear. But under salt water lubricating condition,main wear was adhesive wear.