等离子喷涂NiCrAl/Cr_(2)O_(3)/V_(2)O_(5)-Bi_(2)O_(3)复合涂层的制备及其高温摩擦行为研究

Study on preparation and tribological behaviors under high temperatureof plasma-sprayed NiCrAlYl/Cr_(2)O_(3)/V_(2)O_(5)-Bi_(2)O_(3) composite coating

采用等离子喷涂制备了NiCrAl/Cr_(2)O_(3)/V_(2)O_(5)-Bi_(2)O_(3)复合涂层,并对涂层在600℃下的摩擦学行为进行了研究.结果表明:通过共混球磨、粘接团聚的方法,可制备出微米级且具有较好团聚形貌的V_(2)O_(3)-Bi_(2)O_(3)复合粉体,能够作为Ni基复合涂层的等离子喷涂喂料.复合涂层在600℃的平均摩擦系数为0.33,且得益于良好高温自润滑性能、以及添加Cr_(2)O_(3)能够缓解V_(2)O_(5)-Bi_(2)O_(3)对涂层硬度的不利作用,因而复合涂层磨损率(3.84×10^(-4)mm^(3)/N·m)约为纯NiCrAlY涂层的一半.在高温摩擦下,复合涂层磨痕内生成以BiVO4为主的多元氧化物摩擦化学产物,并表现出易剪切滑移特征,这是复合涂层良好高温自润滑性的主要原因.

NiCrAlY/Cr_(2)O_(3)/V_(2)O_(5)-Bi_(2)O_(3) composite coating was prepared by plasma spraying,and the tribological behavior of the coating at 600℃was studied.The results indicate that V_(2)O_(5)-Bi_(2)O_(3) composite powders with good sphericity and proper micrometer size can be prepared by blending ball milling and bonding agglomeration methods,and the composite powders can be used as plasma spraying feed for Ni-based composite coatings.At 600℃,the composite coating has an average friction coefficient of 0.33 during the stable period.The addition of Cr_(2)O_(3) can alleviate the weakening of the surface hardness by V_(2)O_(5)-Bi_(2)O_(3),resulting in a composite coating wear rate of 3.84×10^(-4)mm^(3)/N·m,which is approximately half of the pure NiCrAlY coating.Under high temperature friction,multiple oxides,mainly BiVO 4,were generated in the worn surfaces of the composite coating.The multiple oxides possessed ability of apt-to shearing and slipping,which should be the main reason of the good high-temperature self-lubricating property.