V-Al-C-N宽温域涂层的制备及其摩擦学行为

目的 设计制备用于高速切削难加工材料的长寿命刀具涂层.方法 采用三靶磁控共溅射技术,通过改变石墨靶材的溅射功率,调控不同润滑相的配比,制备具有不同C含量的V-Al-C-N纳米复合涂层.利用纳米压痕仪和高温摩擦试验机,对涂层的力学性能和摩擦学性能进行检测.采用透射电镜和扫描电镜观察涂层的显微结构和摩擦磨损表面形貌,并分析...

Study on Preparation and Tribological Behavior of V-Al-C-N Coatings in a Wide Temperature Range

To design and prepare long-life tool coating used for high speed cutting the difficult-to-machining materials.In this paper,using three target magnetron sputtering technology,V-Al-C-N nano-composite coatings with different C content were prepared by changing the sputtering power of graphite target and adjusting the ratio of different lubricating phases.The mechanical and friction properties of the coatings were tested by a nanoindentation instrument and a high-temperature friction tester.The microstructure and friction and wear surface morphology of the coating was observed by transmission electron microscope and scanning electron microscope,and its wear mechanism was analyzed.The V-Al-C-N nanocomposite coating had excellent mechanical properties.When the content of C was 29.40at.%,the hardness and elastic modulus of the coating was as high as 36.3 GPa and 370.5 GPa respectively and had good tribological properties in a wide temperature range from RT to 650℃.RT friction conditions are mainly in the form of abrasive wear,with very shallow wear marks.The coefficient of friction(COF)is 0.43.When working at 300℃,compared with VAlN coating,the structure of amorphous wrapped nanocrystals reduces the COF by 14%to 0.72 after C doping.The wear mechanism includes abrasive wear and oxidation wear.At 650℃,a large number of furrows appear in the wear marks,and a large number of wear debris are compacted on both sides of the friction track.At this time,the oxidation reaction is obviously intensified,V₂O₅lubricating phase is formed on the coating surface,and the friction coefficient is stable at 0.35.Using the preparation method of three target magnetron sputtering technology,introduction of C can improve the mechanical properties of VAlN coating,reduce the friction coefficient of the coating at the range of the medium to high temperature to a certain extent.The change of friction coefficient of different coatings is related to the wear mechanism of the coating.