(华北水利水电大学 机械学院，郑州 450011)
摘 要: 采用新型电火花沉积设备，把WC-15Co陶瓷硬质合金材料沉积在铸钢材料上，制备了电火花沉积合金涂层，用SEM、XRD等技术研究沉积层在500 ℃的高温耐磨性和800 ℃高温氧化100 h后的氧化膜形貌、组织结构和高温抗氧化性能。结果表明：沉积层厚度约为30 μm。500 ℃高温条件下，沉积层的耐磨性比基体的耐磨性提高2.7倍，沉积层的磨损机理主要是粘着磨损、疲劳磨损、氧化磨损和磨粒磨损的综合作用；800 ℃高温条件下，沉积层氧化100 h后的氧化膜的厚度约为10~30 μm，氧化膜主要由FeFe2O4、W20O58和CFe2.5物相组成，沉积层的抗氧化性能比基体的提高3.6倍。细小弥散分布的硬质相和致密的氧化膜极大提高沉积层的抗高温磨损性能和抗高温氧化性能。
关键字: WC-15Co硬质合金；电火花沉积；高温耐磨性；高温氧化性
（College of Mechanical, North China University of Water Conservancy and Electric Power, Zhengzhou 450011, China）
Abstract:The ceramic cemented carbide of WC-15Co alloys was deposited on the surface of the cast steel roll by electro-spark deposition (ESD) process, and alloy coatings were formed. The high temperature wear-resistance at 500 ℃ in air and the microstructure, surface morphology and high temperature oxidation resistance at 800 ℃ in air for 100 h of coating were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicate that the thick of coating is 30 μm, and the coating has better high temperature wear resistance which is 2.7 times higher than that of the cast steel substrate at 500 ℃. The wear mechanism of the coating is adhesion wear, fatigue wear, oxidization wear and abrasive wear at 500 ℃. The thick of dense oxide film is 10-30 μｍ for WC-15Co coating at 800 ℃ in air for 100 h and the primary phases in the continuous oxide scales of the coatings contain FeFe2O4, W20O58 and CFe2.5. Their oxidation kinetic curves of the oxide scales follow similar linear law. Their oxidation resistance of the WC-15Co alloys coatings is 3.6 times higher than that of the substrate. The changes in the oxide nature and fine microstructure play a critical role in increasing the high temperature wear resistance and high temperature oxidation resistance of the coating.
Key words: WC-15Co alloy; electro-spark deposition; high temperature wear resistance; high temperature oxidation resistance
