Investigation Of Laser Cladding Wear-resistant Coating On Mold Copper Plate

In this subject,Ni60 powder and Ni60+WC mixed powder of WC mass fraction of 10%,20%,30% as cladding material,then,four kinds of cladding coatings were prepared on the surface of CuCrZr alloy by laser cladding technology,which were Ni60,Ni60+10%WC,Ni60+20%WC,Ni60+30%WC.Firstly,the cladding process parameters were optimized by the orthogonal test with the average hardness of the cladding coating as an indicator.Then,the four kinds of single-channel cladding coating were prepared by optimizing the process parameters,the hardness of cladding coating was tested.The microstructures and element distribution of the cladding coatings were analyzed by SEM and EDS.The phase composition of the clad coatings was analyzed by XRD.Finally,multi-channel cladding coating was prepared by using optimizing the process parameters and overlapping gate 30%.Then,the hardness test,the friction and wear test and the thermal shock test were carried out on multi-channel cladding coating.Also,the performance of multi-channel cladding coating was researched.In the range of process parameters of the subject,the results are as follows.For the Ni60 and Ni60+30%WC cladding coating,the effects of process parameters on its average hardness are ranked as following:cladding speed>laser power>feeding gate.After the process is optimized,the average hardness of the Ni60 and Ni60+30%WC cladding coating is 886 HV and 1113 HV respectively.For the Ni60+10%WC and Ni60+20%WC cladding coating,the effects of process parameters on its average hardness are ranked as following:laser power>cladding speed>feeding gate.After the process is optimized,the average hardness of the Ni60+10%WC and Ni60+20%WC cladding coating is 952 HV and 1072 HV respectively.The cladding coating has element diffusion with the copper matrix,and reaches metallurgical bonding.The main phases of Ni60 and Ni60+WC cladding coating are ?-Ni solid solution,Cr7C3,Cr23C6,CrB,Ni3 B,in addition to the phase of Ni60+WC cladding coating has WC.With the increase of WC content,the average hardness of cladding coating increases.The hardness distribution trend of the multi-channel cladding coating is approximately the same as that of the single-channel cladding coating,but the hardness of the multi-channel cladding coating is lower than that of single channel cladding coating.In the direction of the area near the interface of coating to the substrate,the hardness showed a decreasing trend.The hardness of Ni60 multi-channel cladding coating is 850 HV,which is about 6.5 times the hardness of copper matrix,however,the hardness of Ni60+30%WC multi-channel cladding coating is 1047 HV,which is about 8.1 times the hardness of copper matrix,so adding WC greatly improves the hardness of the cladding coating.The wear resistance of Ni60,Ni60+WC multi-channel cladding coating is good,the wear loss of Ni60 cladding coating is about 1/3 of that of copper matrix,and the wear resistance of Ni60+WC cladding coating is better than that of Ni60 cladding coating.In this experiment,the wear resistance of Ni60+20%WC cladding coating is much better,its wear loss is only about 1/5 of that of copper matrix.At room temperature,the wear mechanism of copper matrix is adhesive wear,and the degree of wear is relatively large.The mainly wear mechanism of multi-channel cladding coating is abrasive wear,and there is also a slight adhesion wear and oxidation wear.Multi-channel cladding coating has good thermal shock resistance.Besides,coating and copper matrix metallurgy combined with good.As the WC content increases,the thermal shock resistance of the cladding coating deteriorates.