等离子喷涂电流对Cr2O3涂层微观形貌与性能的影响

Effect of Plasma Spraying Current on Micromorphology and Properties of CrO Coating

采用大气等离子喷涂技术在Q235B钢板上制备Cr2O3涂层,研究了喷涂电流(570~650A)对Cr2O3涂层孔隙率、微观形貌、物相组成、硬度、结合强度、耐磨性能的影响。结果表明:随着喷涂电流的增大,Cr2O3涂层的孔隙率减小;当喷涂电流为650A时,涂层的孔隙率最低,仅为2.18%,涂层表面平整,与基体结合紧密,未发现明显裂纹及未熔颗粒;喷涂电流为570A时,涂层的物相为Cr2O3,涂层与基体的结合方式为机械结合,喷涂电流增至650A时,涂层主要由Cr2O3、Cr1.3Fe0.7O3组成,涂层与基体间形成了冶金结合;随着喷涂电流由570A增大至650A,涂层的显微硬度由1516.23HV升高至1760.71HV,结合强度由15.60 MPa增大至23.60 MPa,摩擦因数由0.5620减小至0.4369,磨损深度由0.006mm减小至0.004mm,涂层的耐磨性能变好。

Atmospheric plasma spraying technique was applied to prepare Cr2O3 coating on Q235B steel plate.The effect of spraying current(570-650 A)on the porosity,micromorphology,phase composition,hardness,bonding strength and wear resistance of the Cr2O3 coating was investigated.The results show that the porosity of Cr2O3 coating decreased with increasing spraying current.The porosity of the coating prepared at 650 A was the lowest of 2.18%,and the coating surface was flat;the coating and the substrate were tightly bonded,and no obvious cracks and unmelted particles appeared.The phase of the coating prepared at 570 A was Cr2O3,and the combination of the coating and the substrate was mechanical bonding.The coating prepared at 650 A was mainly composed of Cr2O3 and Cr1.3Fe0.7O3,and the metallurgical bonding was formed between the coating and the substrate.As the spraying current increased from 570 A to 650A,the microhardness of the coating increased from1516.23 HV to 1760.71 HV;the bonding strength increased from 15.60 MPa to 23.60 MPa;the friction factor decreased from 0.5620 to 0.4369,and the wear depth decreased from 0.006mm to 0.004mm,indicating that the wear resistance of the coating got better.