| Graphite tanks and refractory tanks are copper outlets in the non-ferrous metallurgical industry and have now been replaced by copper chutes.The copper chute is cast from red copper.Because the copper chute frontal surface is washed by copper liquid copper slag for a long time,its performance will be reduced and it can not be used further.Therefore,users have higher requirements on the service life of copper chute.One of the ways of life.Due to the unique physical and chemical properties of copper and its copper alloys,it is difficult to perform welding on its surface due to local heating.Therefore,this paper uses surface coating technology to prepare a high temperature erosion resistant Ni60 alloy coating on the surface of the copper chute,combining copper and nickel With a variety of similar comprehensive properties,a new type of Ni60 alloy coating with high temperature erosion resistance,high hardness,high bonding strength and simple production is prepared.Using the ZK-F-8000 type supersonic flame spraying process,a multi-factor,multi-level and multi-object visual design method was used to design a test for preparing Ni60 alloy coating on 10 groups of red copper substrates with 4 factors and 10 levels.3V composition analysis spectrometer,BT-9300ST laser particle size distribution analyzer,X-ray diffractometer(XRD),scanning electron microscope(SEM),metallographic microscope(OM),energy spectrum(EDS)and other instruments for coating structure and spraying alloy powder Carry out micro-morphology characterization,and at the same time use digital micro hardness tester,electronic universal material testing machine,coating thickness gauge,surface roughness meter(TR200)and other instruments to test the hardness of the coating,the bonding strength of the coating and the substrate,the coating Layer thickness,surface roughness and other properties were tested and analyzed.To explore the influence of its technological parameters on the bonding strength,coating thickness and microhardness of Ni60 alloy coating,the research results are as follows:1)The cross-sectional macroscopic morphology of the sample is mainly composed of three parts,which are the surface coating structure,the interface between the coating and the copper,and the copper matrix.The analysis of the cross-sectional micro-morphology of the coating shows that the coating is tightly bound to the copper matrix,and there are no obvious defects and particle inclusions at the bonding interface.The alloy coating phase may be mainly composed of Cr3C2,Cu2O,Cu,Cr5Si3,Ni phase,and Cu2O phase.2)Through the multi-factor multi-level multi-target visual analysis method,it is analyzed that the amount of fuel affects the thickness,hardness and bonding strength of the coating.Other test factors:oxygen flow,powder feeding voltage,and carrier gas flow have little effect on the technical indicators,so The impact focuses on research and optimization of the most suitable process parameter range:powder feeding voltage 5.5?7.5 V,oxygen flow 445?640L/h,carrier gas flow 415?450 L/h,fuel flow 35?37 L/h,here Three sets of parameters were selected for the verification test within the range of process parameters,and the coating thickness was measured to be greater than 1000 ?m,the microhardness was greater than 650HV 0.1,and the bonding strength was greater than 70 MPa,which was in line with the technical indicators of experimental design and fitting.3)After the test and verification on the sample of the processing allowance of the copper chute,it is converted into the actual spray application of the copper chute.The optimized process parameters are used:powder feeding voltage 5.5?7.5V,fuel flow 35?37L/h The gas flow rate is 415?450L/h,and the oxygen flow rate is 445?640L/h.The Ni60 alloy high-temperature erosion-resistant coating was prepared on the surface of the copper chute,and the hardness of the coating was measured at 550 HV(a significant improvement compared to the copper 60 HV);the thickness measured by the coating thickness gauge was about 1000 ?m.The preparation of Ni60 alloy coating on the surface of the copper chute by supersonic flame spraying can meet the preparation of the pre-protective coating on the surface of the workpiece in actual production. |
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