等离子渗镀CrON复合涂层结构与抗铝液熔蚀性能

• 作 者: Ahmad Farooq 张林 郑军 Sidra Iram 张世宏
• 机 构: 先进金属材料绿色制备与表面技术教育部重点实验室(安徽工业大学),安徽马鞍山243002;安徽工业大学现代表界面工程研究中心,安徽马鞍山243002;安徽工业大学材料科学与工程学院,安徽马鞍山24300
• 出 处: 稀有金属材料与工程
• 发表日期: 2021年5期
• 关键词: CrON duplex coating microstructure immersion corrosion molten aluminum

采用等离子渗氮/电弧离子镀复合方法在H13模具钢表面制备出CrON涂层,研究氧流量对CrON复合涂层结构及抗铝液熔蚀性能的影响.结果表明,随着氧流量的增加,所制备的涂层主要物相由氮化物向氧化物转变,在氧流量较低时主要呈现面心立方CrN结构,而在氧流量为200mL/min时制备的涂层形成典型的Cr2O3晶体相特征.掺入适量的氧,CrN涂层柱状晶生长受到抑制,涂层结构更加致密.涂层表面缺陷和粗糙度随着氧含量的增加而增大.CrON复合涂层在铝液中的失效形式是局部点蚀.由于形成致密的结构和良好的热稳定性,在氧流量为50 mL/min时制备的涂层具有优异的抗铝液熔蚀能力,而氧流量较高时表面生成致密的Cr2O3抗氧化层也有利于提高抗铝液熔蚀性能.“,”The duplex CrON coatings were prepared on H13 tool steels by combination of plasma nitriding and arc ion plating.The ef-fects of oxygen flow rate on microstructure and corrosion behavior of duplex CrON coating in the molten aluminum were investigat-ed.Results show that the as-deposited coatings with oxygen flow rate of 0,50,and 100 mL/min,namely CrON-0,CrON-50,and CrON-100 coatings,mainly consist of B1-CrN phase.The major components of CrON coating change from nitride into oxide phase with increasing the oxygen flow rate,and the Cr2O3 crystalline phase is obviously observed in the as-deposited coatings with oxygen flow rate of 200 mL/min,namely CrON-200 coating.Oxygen addition in nitride restrains the columnar growth of grains resulting in the dense microstructure.The surface defects and roughness increase with the increase of oxygen content.The failure behavior of du-plex CrON coatings is mainly corrosion pitting in molten aluminium.The CrON-50 coating reveals the best corrosion resistance due to the dense columnar microstructure and high thermal stability.The dense Cr2O3 layer in CrON-200 coating is also favourable for cor-rosion protection against the molten aluminum.