Preparation And Application Of Wear Resistance And Corrosion Resistance Compound Materials On Surface Of Grab Bucket Board For Loading Machine

The abrasion wastage of port and mine machine is all through very large,and so it makes huge economic loss.This thesis ,based on the poor wear resistance condition of grab bucket of loading machine, adopting powder flame spraying-welding method, prepared compound coatings with good abrasion resistance on the substrate of 45 steel(cabon steel which contains 0.45wt% carbon) ,and it also studyed the microscopic structure, abrasion and corrosion resistence of the coating.Using dispersant, micron and nano Al₂O₃ were successfully added to the alloy powder, and this method can efficiently prevent Al₂O₃ from agglomerating and assure Al₂O₃ evenly distributed. Compound coatings were prepared by using blame spray-welding , and abrasion tests were carried out on the abrading grain test machine.This paper studyed the spray-welding technology and wear resistance of the coating under the influence of different quantity and grain size of Al₂O₃ powder;The thesis also studyed the structure and performancenof the coatings with different content of WC; It studied the abrasion resistance of spray-welding coatings with different contant of Al₂O₃ in different conditions. The structure and performance of Ni base Al₂O₃ spay-welding coatings were synthetically analyzed with the use of XRD, SEM, micro-hardness tester and so on.The results indicated that, by adding Al₂O₃ the wear resistance of Ni60A spray-welding coating was greatly improved, and the wear resistance of the coating first improved and then gradually decreased with the increasing of Al₂O₃ at some range. The abrasion resistance of the micron Al₂O₃ spray-welding coating reached the maximum value at the content of 0.75wt% Al₂O₃ , and nano Al₂O₃ spray-welding coating have the best abrasion resistance at the content of 0.5wt% Al₂O₃.These values were about twice as mush as that of singularity coating; Ni base micron Al₂O₃ spray-welding coating has good abrasion resistance in the condition of high loading and long time abrasion; It was discovered that, the best abrasion resistance of the Ni base WC spray-welding coating was reached at the content of 35wt% WC; the coating's brittleness increased when the content of WC was overage, and it also dicreased the spray-welding technology; It also discovered that, the adding of Al₂O₃...