摘要:
在322、402和462 L/min 3种氧气流量条件下采用超音速火焰喷涂技术制备了3种TiB2-50Co涂层,通过SEM和XRD对涂层的微观组织和物相结构进行分析,测试其硬度,采用水淬法测试涂层的抗热震性能,并研究了涂层的耐熔融铝硅(Al-12.07wt%Si)合金腐蚀和耐磨粒磨损性能.研究结果表明:3种TiB2-50Co涂层的物相均为TiB2和Co;3种涂层的组织均致密,其中以氧气流量为322 L/min条件下制备的涂层试样最致密,其孔隙率最低(1.76%),涂层硬度值最高,达到(558±90) HV0.3;氧气流量为462 L/min条件下制备的涂层抗热震性能最差,涂层截面出现明显裂纹;在熔融Al-12.07wt%Si合金中腐蚀60 h后,3种涂层均具有良好的耐熔融Al-12.07wt%Si腐蚀性能;在载荷为6 N的条件下,3种涂层均具有良好的耐磨损性能,以氧气流量为322 L/min条件下制备的涂层试样最佳.
Abstract:
Three kinds of TiB2-50Co coatings were fabricated by high velocity oxygen fuel method at three different oxygen flow rates, including 322, 402 and 462 L/min.The microstructure and phase structure of TiB2-50Co coatings were analyzed by SEM and XRD. The microhardness was tested, and the properties of thermal shock resistance were tested by water quenching method. The corrosion resistance to molten Al-12.07wt%Si alloy and abrasive wear were investigated. Results show that the phases of three kinds of TiB2-50Co coatings are TiB2 and Co. Three kinds of TiB2-50Co coatings have denser structure, especially the coating prepared under oxygen flow rate 322 L/min has much denser microstructure, the lowest porosity(1.76%) and the highest hardness value (558±90) HV0.3. The coating prepared under oxygen flow rate 462 L/min has the worst thermal shock resistance performance with obvious microcrack. And the coatings have good durability in the molten Al-12.07wt%Si alloy after 60 h immersion test. The coatings have good abrasive wear performance after abrasive wear test with 6 N load, especially the coating prepared under oxygen flow rate 322 L/min has the best abrasive wear performance.
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