(華北水利水電大學(xué) 機(jī)械學(xué)院，鄭州 450011)
摘 要: 采用新型電火花沉積設(shè)備，把WC-15Co陶瓷硬質(zhì)合金材料沉積在鑄鋼材料上，制備了電火花沉積合金涂層，用SEM、XRD等技術(shù)研究沉積層在500 ℃的高溫耐磨性和800 ℃高溫氧化100 h后的氧化膜形貌、組織結(jié)構(gòu)和高溫抗氧化性能。結(jié)果表明：沉積層厚度約為30 μm。500 ℃高溫條件下，沉積層的耐磨性比基體的耐磨性提高2.7倍，沉積層的磨損機(jī)理主要是粘著磨損、疲勞磨損、氧化磨損和磨粒磨損的綜合作用；800 ℃高溫條件下，沉積層氧化100 h后的氧化膜的厚度約為10~30 μm，氧化膜主要由FeFe2O4、W20O58和CFe2.5物相組成，沉積層的抗氧化性能比基體的提高3.6倍。細(xì)小彌散分布的硬質(zhì)相和致密的氧化膜極大提高沉積層的抗高溫磨損性能和抗高溫氧化性能。
關(guān)鍵字: WC-15Co硬質(zhì)合金；電火花沉積；高溫耐磨性；高溫氧化性
（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
