大气等离子喷涂FeCoCrNiMn高熵合金涂层的耐海水腐蚀与磨损性能

Tribo-corrosion Performance of Atmospheric Plasma Sprayed FeCoCrNiMn High Entropy Alloy Coatings

研究了采用大气等离子喷涂技术制备的FeC℃rNiMn高熵合金涂层在模拟海水环境中的耐腐蚀与磨损性能。FeC℃rNiMn高熵合金涂层由单相FCC固溶体组成;涂层平均硬度为221.1HV_(0.2),高于304不锈钢基体的表面平均硬度159.1HV_(0.2)。在3.5%NaCl溶液中,FeC℃rNiMn高熵合金涂层在5 N和10 N载荷下的磨损体积分别为1.21×10^(-2)和1.42×10^(-2)mm^(3),相差17%,其主要磨损机制为腐蚀磨损和氧化磨损;在去离子水中该涂层在5 N和10 N载荷下的磨损体积分别为1.15×10^(-2)和1.28×10^(-2)mm^(3),相差11%,主要磨损机制为黏着磨损和氧化磨损。综合比较,NaCl溶液中涂层的磨损体积高于其在去离子水中的磨损体积,且涂层在NaCl溶液中5 N和10 N载荷下的磨损体积差值大于在去离子水中的磨损体积差值,说明磨损体积随载荷增大而增大的幅度受腐蚀介质影响,NaCl溶液的腐蚀效应对摩擦磨损起到促进作用。同时,在NaCl溶液中,低载荷磨损样品的开路电位可在静置浸泡阶段较短时间内恢复到接近摩擦前水平,而高载荷磨损样品由于机械损伤较大,开路电位上升缓慢,难以恢复到摩擦前水平,说明摩擦磨损造成的机械损伤会加剧腐蚀。

Herein,FeC℃rNiMn high entropy alloy coatings were prepared on 304 stainless steel,using atmospheric plasma spraying technique.The tribo-corrosion behavior of the coating was studied in simulated seawater.Results show that the FeC℃rNiMn high entropy alloy coating was composed of single FCC phase with an average hardness 221.1HV_(0.2),in contrast,that of the 304 stainless steel is 159.1HV_(0.2).The tribo-corrosion test results showed that in 3.5%NaCl solution,the wear volumes of FeC℃rNiMn high entropy alloy coating under loads 5 N and 10 N differentiated by 17%,which were1.21×10^(-2)mm^(3)and 1.42×10^(-2)mm^(3)respectively.The main wear mechanism was believed to be corrosive wear and oxidative wear.The wear volumes of the coating under loads 5 N and 10 N in deionized water differentiated by 11%,which were 1.15×10^(-2)mm^(3)and 1.28×10^(-2)mm^(3)respectively.The main wear mechanism was also adhesive wear and oxidative wear.The wear volume in NaCl solution higher than in deionized water might suggest that the corrosion effect of NaCl solution promote the wear process.Meanwhile,in NaCl solution,the open circuit potential of the wear samples under lower load could be restored to close to the level before friction motion in a short time during the static soaking stage.However,the open circuit potential of wear samples under higher load increased slowly and was difficult to return to the level before friction motion due to more severe mechanical damage.This phenomenon might indicate that the mechanical damage caused by wear would accelerate the corrosion process.