工作气体对含氢DLC涂层热稳定性及力学性能的影响  

Effect of Working Gas on the Thermal Stability and Mechanical Property of Hydrogenated DLC Coatings

作　　者：毕君 彭继华[3] 李烈军[2] 周峰 BI Jun;PENG Ji-hua;LI Lie-jun;ZHOU Feng(College of Mechanical and Electrical Technology,Guangdong IndustryPolytechnic,Guangzhou 510300,China;a.School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China;School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 510640,China;School of Mechanical and Electrical Engineering,Foshan Polytechnic,Foshan 528137,China)

机构地区：[1]广东轻工职业技术学院机电技术学院,广东广州510300 [2]华南理工大学机械与汽车学院,广东广州510640 [3]华南理工大学材料学院,广东广州510640 [4]佛山职业技术学院机电工程学院,广东佛山528137

出　　处：《材料保护》2021年第6期16-21,63,共7页Materials Protection

基　　金：广州市科技计划项目(项目标号201902010018,201807010091)资助。

摘　　要：为了揭示工作气体对DLC涂层的影响及为DLC在高温下的应用提供参考,通过通过控制工作气体中乙炔含量(C_(2)H_(2)/Ar流量比=100∶0、75∶25、50∶50),采用等离子体增强化学气相沉积(PE-CVD)技术在304不锈钢基体上制备不同含氢量类金刚石薄膜(a-C:H);采用红外退火装置对样品进行了恒温退火处理,使用球-盘式摩擦仪测试了它们的摩擦曲线,并使用显微硬度仪测量了各种处理状态下的显微硬度;使用差热分析仪、拉曼光谱、红外光谱、场发射扫描电镜等分析表征了薄膜的组织结构。研究结果表明:工作气体中乙炔的含量影响DLC涂层的表面形貌和生长速度。随着工作气体中乙炔含量降低,涂层表面趋于光滑平整;DLC生长厚度随工作气体中乙炔含量的减少间呈非线性关系减薄。3组涂层中,75%乙炔制备的涂层sp 3含量最低,但直到高于490℃时退火其I D/I G才开始迅速增加;且从制备态到各种退火态其硬度均高于乙炔含量为100%和50%的工作气体制备的DLC涂层。在相同的压力下,不同C_(2)H_(2)/Ar流量比的类金刚石薄膜的摩擦系数并没有明显的变化,在低温度退火之后的摩擦系数也没有明显的规律,只是在较高温度(490℃)以上,薄膜因为受到高温作用而加速了sp^(3)到sp^(2)的转变从而生成了大量石墨相,导致摩擦系数的下降。In order to reveal the influence of working gas on DLC coating and provide reference for the application of DLC at high temperature,different hydrogen-containing diamond-like carbon films(a-C:H)were prepared on 304 stainless steel substrate by plasma-enhanced chemical vapor deposition(PE-CVD)with different acetylene contents in the working gas(C_(2)H_(2)/Ar flow ratio=100∶0,75∶25,50∶50).The sample was annealed at constant temperature by infrared annealing device,and their friction curves using a ball-disc friction apparatus and microhardness using a microhardness tester in various treatment states were tested.Using a differential thermal analyzer,Raman spectroscopy,infrared spectrum and field emission scanning electron microscopy,the structure of the film was characterized.Results showed that the acetylene content in the working gas affected the surface morphology and growth rate of the DLC coating.As the acetylene content of the working gas decreased,the coating surface tended to be smooth;DLC growth thickness decreased nonlinearly with the decrease of acetylene content in the working gas.Among three coatings with different levels of acetylene(100%,75%,50%),the one prepared under 75%acetylene had the lowest sp 3 content,but it did not start to increase rapidly until annealing I D/I G above 490℃.The hardness of DLC coating prepared by working gas with acetylene content of 75%as prepared and annealed state was higher than that of DLC coating prepared by working gas with acetylene content of 100%and 50%.Under the same pressure,there was no significant change in the friction coefficient of diamond-like films with different C_(2)H_(2)/Ar flow ratios.There was no obvious rule of friction coefficient after annealing at low temperature.Whereas,at higher temperatures(above 490℃),the film accelerated the transition from sp^(3)to sp^(2)due to high temperature with the formation of a large number of graphite phases,resulting in a decrease in the friction coefficient.

关 键 词：类金刚石薄膜 PE-CVD 工作气体 热稳定性 力学性能 

分 类 号：TG174.4[金属学及工艺—金属表面处理]