Y_2O_3改性石墨/CaF_2/TiC/镍基合金复合涂层微观组织与摩擦学性能研究  

Study on Microstructure and Tribological Properties of Y_2O_3 Modified Graphite/CaF_2/TiC/Ni-base Alloy Composite Coatings

作　　者：蔡滨[1,2] 谭业发[1] 胡晓光 谭华[1] 唐建[1] 

机构地区：[1]解放军理工大学,南京210007 [2]中国人民解放军驻五八〇八厂军代室,泰安271000 [3]总装备部工兵军代局驻武汉地区军代室,武汉430073

出　　处：《中国机械工程》2015年第1期112-119,共8页China Mechanical Engineering

摘　　要：为提高石墨/CaF2/TiC/镍基合金(GCTN)复合涂层的力学性能和摩擦学性能,运用等离子喷涂技术在45钢表面制备了Y2O3改性GCTN复合涂层,研究了Y2O3对复合涂层的微观组织、显微硬度、断裂韧性和摩擦磨损性能的影响。结果表明:Y2O3改性GCTN复合涂层主要由γ?Ni、CrB、Cr7C3、TiC、CaF2和石墨等物相组成。Y2O3在等离子火焰加热作用下与C元素反应生成活性元素Y,Y净化了复合涂层的微观组织,并细化了CrB、Cr3C7等硬质相晶粒,提高了其致密性。当Y2O3质量分数为0.5%时,复合涂层的显微硬度和断裂韧性分别为593.3MPa和6.82MPa·m1/2,比不含Y2O3的复合涂层分别增大了8%和22%,其机理主要是Y2O3细化了CrB、Cr3C7等硬质相晶粒,起到了细化强化作用。由于GCTN-0.5Y2O3复合涂层的显微硬度和断裂韧性显著提高,减少了其黏着磨损和微观断裂磨损,因而GCTN-0.5Y2O3复合涂层的摩擦因数和磨损率最小,分别为0.085和0.39×10-3 mm3/m。In order to improve the friction and wear properties, the graphite/t CaF2/TiC/Ni-base al- loy（GCTN） composite coatings were modified Y2O3 and prepared by plasma spray on the surface of 45 carbon steel. The microstructure, microhardness, fracture toughness and tribological properties of the composite coatings were researched. The results show that the Y2O3 modified GCTN composite coatings are mainly composed of γ-Ni, CrB, Cr7C3, TiC, CaF2 and graphite. Y20a reacts with C and produces active element Y by the heat of plasma flame. Y can purify the 7-Ni structure, refine the grain size of CrB and Cra C7, and improve the density of the composite coating. When Y2O3 is 0.5wt%, the microhardness and fracture toughness of the composite coating are 593.3 MPa and 6.82 MPa mrespectively, which are increased by 8% and 22%than those of the composite coating without Y2O3, because of the refining strengthening effort of CrB and Cr3 C7. The improvement of microhardness and fracture toughness of the GCTN-0.5Y2O3composite coating reduces the adhesive wear and micro fracture wear, so it presents the lowest friction coefficient and wear rate, which are 0. 085 and 0.39X10-a mma/m respectively.

关 键 词：复合材料 Y2O3 石墨 CAF2 摩擦磨损 涂层 

分 类 号：TH117.1[机械工程—机械设计及理论]