摘要
为提高镍基合金涂层在苛刻摩擦条件特别是高温无润滑时的摩擦磨损性能，在45#钢表面制备了CaF2和TiC颗粒协同改性镍基合金复合涂层，分析其微观结构，研究其在不同温度下的摩擦磨损行为与机理。结果表明：CaF2／TIC／镍基合金复合涂层的微观组织呈层状分布，主要由γ-Ni、CrB、Cr7C3、TiC和CaF2物相组成。CaF2／TIC／镍基合金复合涂层在不同环境温度下具有优异的减摩耐磨性能。从室温到500℃，复合涂层的摩擦系数由0．42逐渐减小至0．29，较镍基合金涂层降低16．2％～33．9％。随着环境温度的升高，复合涂层的磨损失重逐渐减小，且大幅度低于镍基合金涂层。温度为500℃时，复合涂层磨损表面形成了转移膜，转移膜中含有CaF2，起到高温减摩作用，使其摩擦系数降低。复合涂层的磨损机理主要为转移膜的疲劳剥落。随着温度的升高，转移膜的覆盖面积逐渐增大，对复合涂层起到保护作用，使其磨损失重随温度增加而减小。
In order to improve the friction and wear properties of Ni-base alloy composite coatings in the condition of rigor friction , especially in the condition of high temperature dry friction, Ni-base alloy com- posite coating modified by CaF2 and TiC particles is prepared on the surface of 45 carbon steel. The mi- crostructure of composite coating is analyzed. The tribological behaviors and mechanisms of the composite coating are researched. The results show that CaFa/TiC/Ni-base alloy composite coating presents the la- mellar microstructure, which is composed of the phases of γ-Ni, CrB, Cr7C3 , TiC and CaF2. The CaF2 TiC/Ni-base alloy composite coating has excellent anti-friction and anti-wear properties at various temperatures. The friction coefficient of the composite coating decreases from 0.42 to 0.29 as the temperature increase from room temperature to 500 ℃ , which is 16.2% - 33.9% less than that of Ni-base alloy coat- ing. The wear losses of the composite coating gradually decrease as the temperature increases, which is sharply reduced compared at of Ni-base alloy coating. The transferred layer is prepared on the worn surface of the composite coating at 500 ℃. The transferred layer contains CaF2 which has the anti- friction effect at high temperature, so the friction coefficient of the composite coating is reduced. The wear mechanism of the composite coating is mainly the fatigue delamination of the transferred layer. The coverage area of the transferred layer, which may protect the composite coating, increases with tempera- ture. So the wear loss of the composite coating decreases with the increasing temperature.
出处
《兵工学报》
EI
CAS
CSCD
北大核心
2014年第6期900-907,共8页
Acta Armamentarii
关键词
复合材料
涂层
高温
减摩
耐磨
composite material
coating
high temperature
anti-friction
anti-wear
