Effect Of Sealing Treatment On The Corrosion And Wear Behaviors Of Fe-based Amorphous Coatings

The amorphous coating has high hardness,good corrosion resistance and wear resistance,and has a wide application prospect in the field of surface engineering.However,it was found that the pores generated during the spraying process greatly affect the serviceability and service life of the amorphous coating.In this dissertation,in order to solve this problem,a new sealing process for amorphous coating was studied,and the structure,corrosion and frictional wear properties of the amorphous coating before and after the sealing were systematically studied.In this paper,a Fe_43.7Co_7.3Cr_14.7Mo_12.6C_15.5B_4.3Y_1.9?at.%?amorphous coating was prepared by supersonic flame spraying technique.The amorphous coating was sealed by PTFE ultrasonic sealing process.X-ray diffractometer?XRD?and scanning electron microscope?SEM?were used for structural analysis.The contact angle tester was used to measure the contact angle of the coating.Electrochemical Workstation and Salt Spray Corrosion Tester?Salt?were used.The spray corrosion test chamber was used to evaluate the corrosion resistance of the coatings.The tribological properties of the coatings were measured using a Friction and Wear tester.It was found that the corrosion and frictional properties of the amorphous coating after PTFE ultrasonic sealing were better than those of the amorphous coating after the traditional aluminum phosphate sealing and the amorphous coating without the sealing treatment.For example,the value of the impedance modulus|Z|of the amorphous coating after the PTFE sealing is 10 times that of the aluminum phosphate-sealed amorphous coating,and the former has a more excellent sealing effect and corrosion resistance.In addition,because PTFE is a low surface energy material,the static contact angle of the amorphous coating after PTFE sealing is up to 120°,which has a certain degree of hydrophobicity,and at a certain inclination angle,the water droplets can naturally roll off.The salt spray corrosion and long-term immersion tests were further used to study the long-term corrosion resistance of the amorphous coating before and after the sealing.The results show that the corrosion resistance of the coating after plugging is significantly improved.It is considered that this is mainly due to the sealing The reduced porosity of the coating reduces the possibility of pitting and other corrosion of the coating.At the same time,PTFE itself has excellent corrosion resistance,and the PTFE particles that seal the hole into the coating play a significant role in improving the corrosion resistance of the coating.The role of performance.The friction and wear test results in dry and wet?3.5%NaCl?environment show that the friction coefficient of the PTFE-sealed coating is 0.2 and 0.15,respectively,which are lower than those of the unsealed amorphous coating.In addition,the wear rate of the PTFE-sealed coating under dry and 3.5%NaCl conditions was only4.5×10^-6mm³/Nm and 3.3×10^-6mm³/Nm,which were much lower than the unsealed ones.The iron-based amorphous coating indicates that the PTFE sealing coating has better friction-reducing and wear-resistance properties.It is considered that the significant reduction of voids and other defects in the amorphous coating and the good lubricating effect of PTFE itself are the main reasons for the improved wear resistance of the sealed amorphous coating.