阴极弧与磁控溅射复合技术制备耐磨涂层

发布时间：2018-06-26 19:51

本文选题：阴极弧与磁控溅射复合技术 + 固体耐磨涂层　；参考：《大连理工大学》2015年博士论文

【摘要】：随着高推重比发动机和大型发动机的研发,解决高载荷条件下耐磨润滑问题日益迫切。类金刚石涂层由于其具有低摩擦系数、高耐磨性等优点业已成为解决军工产品耐磨问题的首选材料。但是单层结构类金刚石涂层的承载能力较差,且内应力较大、膜基界面结合力较差,在高载荷下易于发生断裂、剥离等失效行为。为了解决这一问题,国外正在研发粘结层(金属层)+承载层(耐磨层)+润滑层(DLC)这种耐磨润滑涂层体系。通过功能化梯度过渡层与承载层的设计,可使涂层的组分和微观结构沿涂层生长方向梯度渐变,显著提高涂层与基体的结合强度和涂层的抗载荷性能。另一方面国际上涂层制备技术正朝着大面积加工、复合加工和高表面质量加工方向发展,鉴于此本论文首先进行了阴极弧与磁控溅射技术的复合研究,从复合源技术研究入手,解决矩形阴极弧源大面积燃烧和可控烧蚀问题,并将其与中频磁控溅射复合,从而实现大面积加工和高表面质量涂层。在此基础之上,再进行具有高承载力的类金刚石耐磨涂层研究。本论文主要包括以下几个部分： (1)首先设计并优化了矩形大面积可控弧靶(尺寸为430mmx125mm),通过可编程线圈电源设计,利用线圈电流对磁场产生微扰作用,实现对弧斑燃烧轨迹的控制,使得其按照扫描式轨道进行燃烧,大大提高靶材刻蚀均匀性和靶材利用率；将可控弧靶与中频磁控溅射靶复合到同一设备中,以满足制备多层结构涂层的需求。对复合源设备,通过磁场模拟测试及等离子体密度测试等手段对沉积环境进行表征,结果表明复合源设备等离子体均匀性较好,复合源开启时真空室内等离子体密度明显高于单个源开启时的等离子体密度值,为8.98×1011/cm3左右,真空室内等离子体密度在101l/cm3以上的有效工作区为φ400×450mm2；利用复合源设备提供的不同技术,对比研究了阴极弧沉积、先弧沉积后磁控溅射沉积、阴极弧与磁控溅射共沉积、磁控溅射沉积四种工艺制备的氮化钛涂层,通过对氮化钛涂层表面断面形貌分析,可以看出复合源沉积的涂层相对于阴极弧沉积样品涂层表面质量明显提高,同时组织结构已无柱状晶生长特征,显示为致密的结构；在400N载荷下,与WC球对磨时,阴极弧与磁控溅射复合沉积的涂层耐磨寿命最长,为116s。这主要是由于在样品沉积过程中基体随样品架公自转,交替进行弧靶和磁控靶沉积,使得磁控溅射与阴极弧两种技术发挥优势互补作用,制备的涂层呈现出特有的层状致密结构,这种结构有利于提高涂层高载荷下的耐磨性能。 (2)针对类金刚石支撑层部分,采用阴极弧与磁控溅射复合技术,对比研究了Cr/CrN多层结构涂层,包括不同Cr/CrN周期多层和Cr/CrN梯度多层,以便摸索最佳支撑层结构方案。通过对涂层表面断面、晶体结构、成分、硬度、膜基结合力、残余应力和摩擦学性能的表征,发现不同调制多层结构影响着Cr/CrN涂层的晶体结构及残余应力状态,进而影响其力学性能和支撑能力。不同周期Cr/CrN涂层的膜基结合力、硬度和耐磨性能等均随着调制层数目减少而增强,相对于Cr/CrN周期结构多层,梯度Cr/CrN涂层具有最高的硬度,维氏硬度972Hv和纳米硬度27.8GPa(微米硬度为2N载荷下测试),结合力高达62N,在100N载荷下与WC球对磨,其磨损率最低,为32.54×10-6mm3/Nm。梯度结构Cr/CrN涂层由于在制备过程中以100sccm/step的方式逐渐增加氮气流量,使得涂层内形成成分连续变化和硬度连续变化,涂层硬度和应力之间具有良好的匹配,使得其具有最优耐磨性能和最佳支撑能力。梯度结构Cr/CrN涂层是可用于具有高承载能力的碳基复合涂层承载层的最佳选择。 (3)在最佳结构支撑层(梯度结构Cr/CrN支撑层)基础上,利用阴极弧、磁控溅射和分解C2H2气体的化学气相沉积技术,制备具有过渡层、承载层和减磨顶层的类金刚石涂层,其涂层结构为Cr/(Cr/CrN梯度层)/CrCN/CrC/Cr-DLC,顶层Cr-DLC中金属Cr的梯度掺杂量可通过调节弧靶电流控制弧靶中毒速度实现。通过对比发现弧靶电流为120A制备的涂层综合性能最好,硬度高达36.5GPa,结合力为52N,涂层内sp3键含量最高；而对具有不同结构支撑层的Cr-DLC复合涂层进行球盘方式摩擦磨损测试,于干摩擦下与WC球对磨3600转(测试载荷为100N),具有梯度支撑层的Cr-DLC复合涂层磨痕深度最浅(为7.241μm),磨损率最低,为13.8×10-7mm3/Nm,相对于无CrN支撑层的Cr-DLC复合涂层其耐磨性能提高了近10倍。基于功能梯度过渡、梯度掺杂的多层膜成膜思想,采用阴极弧与磁控溅射复合技术,通过优化承载层(Cr/CrN)与润滑层(DLC)结构方案,制备出具有梯度多层结构的Cr-DLC复合涂层,厚度大于13.5μm,在高载荷下表现出很好的应用前景。
[Abstract]:With the development of high thrust weight ratio engine and large engine, it is becoming more and more urgent to solve the problem of wear-resistant lubrication under high load conditions. The diamond like coating has become the first choice to solve the wear resistance of military products because of its low friction coefficient and high wear resistance. But the bearing capacity of the single layer diamond like coating is poor, and In order to solve this problem, in order to solve this problem, the wear-resistant coating system of adhesive layer (metal layer) + bearing layer (wear-resistant layer) + lubricating layer (DLC) is being developed abroad. Through the design of functionalized gradient transition layer and bearing layer, the coating can be made. The composition and microstructure of the coating gradually change along the direction gradient of the coating growth, which significantly improves the bonding strength of the coating and the substrate and the load resistance of the coating. On the other hand, the coating preparation technology is facing the large area, the composite processing and the high surface quality processing are developing. In this paper, the cathode arc and magnetron sputtering technique is first carried out in this paper. The complex study of the operation, starting with the research of composite source technology, solves the problem of large area combustion and controllable ablation of rectangular cathode arc source, and compounded it with medium frequency magnetron sputtering, so as to achieve large area and high surface quality coating. On this basis, the research on high bearing capacity of diamond like wear resistant coating is carried out. The main package of this paper is the main package The following are the following parts:
(1) first, the rectangular large area controllable arc target (size 430mmx125mm) is designed and optimized. Through the design of the programmable coil power supply, the coil current is used to produce the perturbation of the magnetic field to realize the control of the trajectory of the arc spot combustion, which makes it burning according to the scanning orbit, and greatly improves the uniformity of the target etching and the utilization rate of the target. The arc target and the medium frequency magnetron sputtering target are compounded to the same equipment to meet the needs of preparing the multilayer structure coating. The composite source equipment is characterized by magnetic field simulation test and plasma density test. The results show that the plasma uniformity of the composite source is better, and the vacuum chamber is separated when the composite source is opened. The density of the plasma is obviously higher than that of the single source. It is about 8.98 x 1011/cm3, and the effective working area of the plasma density above 101l/cm3 in the vacuum chamber is 400 x 450mm2.
Using the different technology provided by the composite source, the cathode arc deposition, the magnetron sputtering deposition after the arc deposition, the co deposition of the cathode arc and the magnetron sputtering, and the magnetron sputtering deposition of the four kinds of titanium nitride coatings have been studied. By analyzing the surface profile of the titanium nitride coating, it can be seen that the coating of the composite source deposited relative to the cathode. The surface quality of the arc deposited sample coating is obviously improved, and the structure of the structure has no columnar crystal growth and shows a compact structure. Under the load of 400N, the wear resistance life of the coating deposited by the cathode arc and magnetron sputtering is the longest, which is mainly due to the rotation of the matrix with the sample frame during the sample deposition. The deposition of arc target and magnetic target makes the two technologies of magnetron sputtering and cathode arc complementary to each other. The prepared coating presents a unique and compact structure. This structure helps to improve the wear resistance of the coating under high load.
(2) for the diamond like support layer, using the cathode arc and magnetron sputtering composite technology, the Cr/CrN multilayer coating, including different Cr/CrN periodic multilayer and Cr/CrN gradient multilayer, is studied in order to find out the best support layer structure scheme. The characterization of tribological properties shows that the structure and residual stress state of the Cr/CrN coating are affected by different modulation multilayer structures, and then the mechanical properties and supporting capacity of the coatings are influenced. The adhesion, hardness and wear resistance of the film based on the different cycle Cr/CrN coatings are enhanced with the decrease of the number of modulation layers, and the multilayer of the Cr/CrN periodic structure. The gradient Cr/CrN coating has the highest hardness, the hardness 972Hv of Vivtorinox and the nano hardness 27.8GPa (microhardness of 2N under 2N load), the binding force is as high as 62N, and the wear rate is the lowest under 100N load with the WC ball, and the 32.54 x 10-6mm3/Nm. gradient structure Cr/CrN coating gradually increases the nitrogen flow in the process of 100sccm/step. As a result, the continuous change in the composition of the coating and the continuous change of the hardness and the good match between the hardness and the stress of the coating make the coating have the best wear resistance and the best support ability. The gradient structure Cr/CrN coating is the best choice for the bearing layer of a carbon based composite coating with high bearing capacity.
(3) on the basis of the best structural support layer (the gradient structure Cr/CrN support layer), the CVD coating with the cathode arc, magnetron sputtering and decomposition of C2H2 gas is used to prepare the diamond like coating with the transition layer, the bearing layer and the antiwear top layer. The coating structure is Cr/ (Cr/ CrN gradient layer) /CrCN/CrC/Cr-DLC, the gradient of metal Cr in the top layer Cr-DLC is mixed. The impurity can be controlled by the arc target current to control the arc target poisoning speed. By contrast, it is found that the coating has the best comprehensive performance, the hardness is up to 36.5GPa, the bonding force is 52N, the SP3 bond in the coating is the highest, and the Cr-DLC composite coating with different structure support layer is tested by the friction and wear test of the ball disk mode, and at the same time, the 120A composite coating with different structure support layer is dry and worn. The wear resistance of the Cr-DLC composite coating with the gradient support layer is the shallower (7.241 m), the wear rate is the lowest, and the wear rate is 13.8 x 10-7mm3/Nm. The wear resistance of the Cr-DLC composite coating is nearly 10 times higher than that of the Cr-DLC composite coating without the CrN support layer.
Based on the functionally gradient transition and gradient doped multilayer film formation, the Cr-DLC composite coating with a gradient multilayer structure is prepared by using the cathode arc and magnetron sputtering composite technology. By optimizing the structure of the bearing layer (Cr/CrN) and the lubricating layer (DLC), the thickness is more than 13.5 mu m, showing a good application prospect under high load.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG174.4

【参考文献】