Investigation of processing parameters for pulsed closed-field unbalanced magnetron co-sputtered TiC-C thin films

Titanium carbide is a well-established wear resistant coating due to its excellent tribological properties including high hardness and elastic modulus, good wear resistance, low coefficient of friction against steel, and high temperature stability. Recent advances in sputtering technology have resulted in improvements in the properties and performance of wear resistant coatings. Closed-field unbalanced magnetron sputtering and pulsed magnetron sputtering have greatly improved the structure and properties of titanium carbide films by increasing ion bombardment at the substrate. The goal of this research was to investigate how processing ties into the structure-property-performance relationship for these types of films. An electrostatic quadrupole plasma analyzer was used to measure the energy of ions at the substrate position. Energy ranges from 0.5 to 280 eV were observed under different pulsing conditions. Excessively high ion energy during deposition was found to erode the tribological performance of films.     

TC4 表面等离子 Ni 改性层摩擦磨损研究

目的研究TC4表面等离子Ni改性层摩擦磨损情况,以提高航空用钛合金的使用寿命。方法以近等原子比Ti Ni二元合金作为源极靶材,利用等离子表面合金化技术在TC4表面制备Ni改性层,考察合金层的组织、成分、相结构以及硬度分布,分析Ni改性层和基体的摩擦学性能。结果 Ni改性层主要由Ti2Ni,Ti Ni,Ti等相组成,Ni原子数分数最高为18%;表面硬度高达625HV;改性后的摩擦系数与基体相近,磨痕宽度是基材的1/3。结论 TC4表面等离子Ni改性层耐磨性增加。     

MoS2-Zr复合薄膜的摩擦学性能研究

目的改善MoS_2薄膜的疏松结构,提高其硬度及摩擦磨损性能。方法采用离子源辅助磁控溅射技术在GCr15基体上沉积不同Zr含量的MoS_2-Zr复合薄膜,通过SEM分析薄膜的表面及截面形貌。采用EDS检测薄膜的成分,采用显微维氏硬度计测试薄膜的硬度,采用Rockwell-C硬度计进行压痕测试实验,采用球-盘式旋转摩擦磨损试验机评价薄膜的摩擦磨损性能。结果 MoS_2-Zr复合薄膜的致密程度和硬度随着Zr含量的增加而增大,其硬度值为300~500HV。复合薄膜与基体的结合力随着Zr含量的增加而增强,但当Zr含量过高时,结合力下降。含Zr原子数分数为15%的MoS_2-Zr复合薄膜具有最好的摩擦学性能,其平均摩擦系数为0.09,磨损率为9.33×10~7 mm~3·N~(–1)·m~(–1),耐磨寿命达5.25×105 r。结论 Zr的掺杂改善了纯MoS_2薄膜的疏松结构,提高了MoS_2薄膜的硬度和结合力,合适的Zr掺杂可以获得较低的摩擦系数和较长的耐磨寿命。     

Ceramic Conversion Treatment of Titanium Aluminide for Improved Tribological Properties

GAMMA based titanium aluminides have greatpotential for high temperature applications,such as jetengine components and exhaust valves in car engines,owing to their high specific strength,high stiffness andgood creep resistance at elevated temperatures[1,2,3].For some of the proposed applications,e.g.,valves in acar engine involving tribo-contact,tribologicalproperties could be thus one of the crucial factors indetermining the life and performance of a titaniumaluminide part.A few studies have…     

基于自组装技术改性处理钛金属的摩擦学特性研究

为了使钛金属应用于具有相对运动的摩擦副,采用自组装技术对钛金属表面进行改性处理,并对制备的试样进行紫外照射.利用接触角测量仪、原子力显微镜和微摩擦磨损试验机对制备的试样进行表征和摩擦学特性测试,探讨不同方法进行钛金属表面羟基化的作用效果,并分析载荷、滑动速度以及紫外照射对试样摩擦学特性的影响.结果表明:Piranha溶液结合紫外照射能有效地提高钛基底的羟基化程度,经FOTS(Perfluorooctyltrichlorosilane)自组装分子膜改性处理的钛金属表面平整均匀,具有疏水特性和良好的摩擦学性能.Si_3N_4球与FOTS自组装分子改性处理试样间的摩擦系数随载荷和滑动速度的增大而增大.紫外照射5 min可有效地提高FOTS自组装分子膜改性处理的效果,在降低摩擦系数的同时,薄膜也具有良好的耐久性.     

低温磁控溅射与普通多弧离子镀TiN薄膜的摩擦学性能比较

采用低温磁控溅射和普通多弧离子镀分别在冷作模具钢基体上制备了TiN薄膜，用纳米压痕法测量了薄膜的表面硬度，并比较了低温磁控溅射与普通多弧离子镀TiN薄膜的摩擦学性能。试验表明，低温磁控溅射TiN薄膜具有与普通多弧离子镀TiN薄膜相近的表面硬度，在多种试验条件下，低温磁控溅射TiN薄膜都有较好的摩擦学性能，摩擦副的磨损率低，摩擦因数小且变化平稳，磨损表面光滑。     

Nanoscale triboactivity: The response of Mo–Se–C coatings to sliding

Mo–Se–C films were deposited by sputtering from a carbon target with pellets of MoSe₂. In addition to the standard evaluation of their chemical composition, structure, morphology, hardness and cohesion/adhesion, the core objective of this paper was to analyze the tribological behavior of these films, particularly in the high-load regime. The carbon content varied from 29 to 68 at.% which led to a progressive increase of the Se/Mo ratio and the hardness. The friction coefficient of Mo–Se–C coatings clearly decreased with load from ∼0.15 to ∼0.05. The excellent friction properties were attributed to the formation of a thin molybdenum diselenide film on the top of the wear track of the coating and on the counterpart surface, while the role of the carbon in the sliding process is only secondary by increasing the coating hardness and thus its wear resistance.     

Tribological evaluation of diamond coating on pure titanium in comparison with plasma nitrided titanium and uncoated titanium

Titanium alloys are characterized by poor tribological properties, and the traditional use of titanium alloys has been restricted to nontribological applications. The deposition of a well adherent diamond coating is a promising way to solve this problem. In this study, the tribological properties of diamond-coated titanium were studied using a pin-on-disk tribometer, and the results were compared with those of pure titanium and plasma nitrided titanium. The tribological behavior of pure titanium was characterized by high coefficient of friction and rapid wear of materials. Plasma nitriding improved the wear resistance only under low normal load; however, this hardened layer was not efficient in improving the wear resistance and the friction properties under high normal load. Diamond coating on pure titanium improved the wear resistance of titanium significantly. Surface profilometry measurement indicated that little or no wear of the diamond coating occurred under the test conditions loads. The roughness of the diamond coating was critical because it controlled the amount of abrasive damage on the counterface. Reducing the surface roughness by polishing led to the reductions in both the friction and wear of the counterface.     

Surface modification of Al-Pb alloy by high current pulsed electron beam

Al-Pb alloy was modified by high current pulsed electron beam and the microstructure, hardness and tribological characteristics were characterized by scanning electron microscopy, electronic microanalysis probe microanalysis, Knoop hardness indentation and pin-on-disc type wear testing machine. The results show that the microstructure and hardness can be greatly improved, and the modification layer consists of a molten zone, an overlapped zone of heat-affected and quasistatic thermal stress-affected zone and a transition zone followed by the substrate. The tribological properties of high current pulsed electron beam irradiated Al-Pb alloy are correspondingly improved largely. Optical observation and scanning electron microscopy analysis reveal that the low wear rate and lowest level in coefficient of friction at high load level for irradiated Al-Pb alloy are due to the formation of a lubricious tribolayer covering the worn surface, which is a mixture of Al2O3, Pb3O4 and silicate. The wear mode varies from oxidative wear at low load to film spalling at high load and, finally, adhesive wear.     

偏压对DLC薄膜结构及摩擦学性能的影响

目的通过调节偏压,改善无氢DLC薄膜的微观结构,提高其力学性能和减摩抗磨性能。方法采用离子束辅助增强磁控溅射系统,沉积不同偏压工艺的DLC薄膜。采用原子力显微镜(AFM)观察薄膜表面形貌,采用拉曼光谱仪对薄膜的微观结构进行分析,采用纳米压痕仪测试薄膜硬度及弹性模量,采用表面轮廓仪测定薄膜沉积前/后基体曲率变化,并计算薄膜的残余应力,采用大载荷划痕仪分析薄膜与不锈钢基体的结合力,采用TRB球-盘摩擦磨损试验机评价薄膜的摩擦学性能,采用白光共聚焦显微镜测量薄膜磨痕轮廓,并计算薄膜的磨损率。结果偏压对DLC薄膜表面形貌、微观结构、力学性能、摩擦学性能都有不同程度的影响。偏压升高导致碳离子能量升高,表面粗糙度呈现先减小后增加的趋势,-400V的薄膜表面具有最小的表面粗糙度且C─C sp^3键含量最多,这也导致了此偏压下薄膜的硬度最大。薄膜的结合性能与碳离子能量大小呈正相关,-800 V时具有3.98 N的最优结合性能。不同偏压工艺制备的薄膜摩擦系数随湿度的增加,均呈现减小的趋势,偏压为-400V时,薄膜在不同湿度环境中均显示出最优的摩擦学性能。结论偏压为-400 V时,DLC薄膜综合性能最优,其表面粗糙度、硬度、结合力和摩擦系数分别为2.5 nm、17.1 GPa、2.81 N和0.11。     

磁流体极性对钛合金表面织构的摩擦学性能研究

目的 研究磁流体的极性对钛合金光滑表面和织构表面摩擦学性能的影响。方法 以水基磁流体、煤油基磁流体、去离子水和煤油为润滑剂,在UMT?3摩擦磨损试验机上分别进行钛合金光滑表面和织构表面的摩擦磨损实验,得到极性不同的磁性颗粒对不同表面的摩擦因数、磨损量和磨损形貌的影响规律。结果 在光滑钛合金表面,极性磁性颗粒使得摩擦因数下降了8.42%,磨痕宽度下降了8.47%,磨损方式由严重的磨粒磨损和黏着磨损转变为轻微的磨粒磨损。非极性磁性颗粒使得摩擦因数上升了33.94%,磨痕宽度上升了42.20%,磨损方式由轻微的黏着磨损转变为严重的磨粒磨损。在织构表面,极性磁性颗粒的减摩作用进一步增强,而非极性磁性颗粒并没有明显的减摩作用。结论 采用不同极性磁流体润滑时,极性磁性颗粒更容易吸附在钛合金表面,从而增加油膜的厚度和刚度,减小其摩擦因数。     

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...     

海水环境中钛元素改性铜基激光熔覆层的摩擦行为研究

目的通过激光熔覆作用,使钛元素与铜基合金生成耐磨的第二相组织,提升铜基合金表面在海水环境中的耐磨性能。方法采用激光熔覆技术在ZQAl9442镍铝青铜合金表面制备均匀的钛元素改性铜基涂层。采用SEM、EDS、XRD、摩擦磨损试验机等检测仪器,对该改性涂层的显微组织、元素分布、硬度以及在大气与海水环境中的摩擦性能进行分析。结果改性涂层中,因钛元素添加生成了Al Cu2Ti相,使得改性涂层的表面硬度在第二相析出强化的作用下得以提升,显微硬度可达(310±10)HV0.3,相比同质修复层,提升了14.8%。在海水环境中,改性涂层的摩擦系数远低于同质修复层。改性涂层在大气环境中的磨损机制为氧化磨损、粘着磨损及磨粒磨损,在海水环境中的磨损机制为磨粒磨损。结论通过在ZQAl9442铜合金表面进行激光熔覆,得到了兼具高硬度、高耐磨性和抗海水环境摩擦的钛元素改性铜基涂层,在一定程度上提升了镍铝青铜合金在海水环境中的服役寿命。     

脉冲偏压对直流磁控溅射沉积MoN薄膜结构及性能的影响

MoN薄膜是一种具有潜在应用价值的薄膜材料,但对于其结构和性能的研究还较少。采用直流磁控溅射技术在304不锈钢基体表面沉积MoN薄膜,研究了脉冲偏压对MoN薄膜结构和性能的影响,并系统研究了MoN薄膜在不同摩擦条件下的摩擦磨损行为。采用X射线衍射仪和扫描电镜分析薄膜的晶相结构、晶粒尺寸、表面及断面形貌,采用HMV-2T显微硬度仪测试薄膜的显微硬度。采用UMT-TriboLab多功能摩擦磨损试验机评价薄膜的摩擦磨损性能,并用扫描电镜观察磨损表面,分析其磨损机制。结果表明：脉冲偏压显著影响直流磁控沉积的MoN薄膜的晶相结构、表面形貌、断面结构、硬度和摩擦磨损性能;随脉冲偏压的增大,MoN薄膜的膜厚、硬度都先增大后减小,而薄膜的磨损率却先减小后增大,其中-500 V脉冲偏压下沉积的MoN薄膜具有最高硬度为7731 N/mm²,以及最低的磨损率为5.8×10^-7 mm³/（N·m）。此外,MoN薄膜在不同载荷和转速的摩擦条件下表现出不同的摩擦学行为。     

Sliding wear characteristics of solid lubricant coating on titanium alloy surface modified by laser texturing and ternary hard coatings

Titanium alloys are poor in wear resistance and it is not suitable under sliding conditions even with lubrication because of its severe adhesive wear tendency. The surface modifications through texturing and surface coating were used to enhance the surface properties of the titanium alloy substrate. Hard and wear resistant coatings such as TiAlN and AlCrN were applied over textured titanium alloy surfaces with chromium as interlayer. To improve the friction and wear resisting performance of hard coatings further, solid lubricant, molybdenum disulphide (MoS2), was deposited on dimples made over hard coatings. Unidirectional sliding wear tests were performed with pin on disc contact geometry, to evaluate the tribological performance of coated substrates. The tests were performed under three different normal loads for a period of 40 min at sliding velocity of 2 m/s. The tribological behaviours of multi-layer coatings such as coating structure, friction coefficient and specific wear rate were investigated and analyzed. The lower friction coefficient of approximately 0.1 was found at the early sliding stage, which reduces the material transfer and increases the wear life. Although, the friction coefficient increased to high values after MoS₂ coating was partially removed, substrate was still protected against wear by underlying hard composite layer.     

Design and characterisation of an advanced duplex system based on carbon S-phase case and GiC coatings for 316LVM austenitic stainless steel

Low temperature plasma carburising of austenitic stainless steels is attracting special attention because it can effectively improve their hardness, wear resistance and fatigue properties by the formation of interstitial supersaturated, super-hard and metastable S-phase. However, this S-phase layer tends to have a high friction coefficient between 0.5 and 0.7 under dry sliding conditions against WC ball. In this study, a new duplex surface system has been designed by combing chromium doped carbon-based GiC coating with S-phase to improve the tribological and load bearing capacity of 316LVM austenitic stainless steel. Laser confocal microscopy, SEM, XRD, XTEM, Micro-scratch and a pin-on-disc tester were employed to characterize the phase constitution, surface morphology, hardness, friction coefficient and load-bearing capacity of the single coated and duplex treated specimens. The results show that the new duplex surface system possesses a desirable combination of properties in terms of low friction (0.1-0.2), high wear resistance and high load bearing capacity.     

含硅无氢非晶碳基薄膜的摩擦磨损性能

为了研究Si掺杂对无氢非晶碳基薄膜摩擦磨损性能的影响,利用直流磁控溅射技术在单晶硅和304不锈钢基底上沉积不同Si含量的无氢非晶碳基薄膜。采用SEM、Raman光谱、纳米压痕仪等分析手段对薄膜的成分、结构和力学性能进行表征。利用球盘式往复摩擦试验机测试薄膜在无润滑条件下的滑动摩擦磨损性能。结果表明:Si掺杂能降低薄膜内应力和促进sp3杂化,高于10%的Si原子导致薄膜硬度增加。在不同湿度条件下,Si掺杂并未明显影响溅射无氢非晶碳基薄膜的摩擦因数;相反,含Si薄膜在不同测试条件下都具有较高的磨损速率。薄膜磨损速率随相对湿度增加而减小,随Si含量增加而增加;高Si含量薄膜在低湿度条件下具有明显不稳定的摩擦因数和显著增加的磨损速率。这意味着在设计和发展性能优异的无氢非晶碳基摩擦学涂层时,应充分考虑Si掺杂导致的性能损失。     

铁基金属摩擦副表面自修复层分析

目的分析不同工况对表层自修复层的影响,探究羟基硅酸镁纳米管在摩擦磨损过程中的作用机理。方法以人工合成的羟基硅酸镁纳米管Mg3Si2O5(OH)4为自修复添加剂,在油润滑实验条件下进行铁基金属摩擦副摩擦磨损实验。利用SEM、EDS、激光拉曼光谱仪及显微维氏硬度计分别对自修复层厚度、自修复层元素组成、自修复层表面结构及自修复层表面显微硬度进行表征。结果在转速为1000、2000 r/min时,载荷为200、300、400 N的实验条件下,表层均有自修复层的生成。在转速为2000 r/min、载荷为400 N时,表层自修复层的厚度最大。实验过程中,摩擦副得到修复,出现负磨损,自修复层的主要元素为C、O、Fe等。高转速载荷工况下,其摩擦系数相比基础油下降0.008。自修复层为类金刚石结构,其平均硬度值在673HV左右,为基体的1.87倍。结论羟基硅酸镁、基础油及磨屑三者共同作用,在高能摩擦作用下合金化,形成高硬度的类金刚石结构修复层,能有效保护摩擦副工作面,并延长寿命。加大实验载荷与实验转速,能加速自修复层的形成,实现摩擦副负磨损,并降低摩擦系数。     

Study on the Tribological Properties of Graphite-like Amorphous Carbon Film under Different Testing Conditions

Graphite-like amorphous carbon film was fabricated by unbalanced magnetron sputtering technique.Raman spectroscopy,atomic force microscopy(AFM)and tribometer were subsequently used to investigate the microstructure and tribological properties of the resultant film.It is found that the deposited carbon film is dominated by sp 2 sites,and the intensity ratio of the D and G peaks is as high as 4.0,which is one order of magnitude larger than that of diamond-like carbon films with high sp 3 content,indicating a more graphite-like structure.However,the as-deposited carbon film exhibits moderately high hardness(13.7 GPa),low internal stress(0.38 GPa)and superior tribological properties with high load bearing capacity(Hertz contact stress about 3.2 GPa)and low wear rate(2.73×10-10 cm3/N.m)in ambient atmosphere.Although it displays a poor wear resistance in water lubricated condition,a superior wear resistance is achieved in oil lubricated condition.Its inherent physical property,the formation of transfer layer and the friction induced chemical reactions may be commonly responsible for its tribological properties.     

等温淬火处理对感应重熔镍基合金涂层摩擦学性能的影响

目的改善镍基合金涂层的摩擦学性能。方法分别采用感应重熔工艺及感应重熔-等温淬火一体化工艺,在GCr15钢基体表面制备了两种镍基合金涂层,并通过销盘摩擦磨损试验、扫描电子显微镜、X射线衍射仪、显微硬度测试对其摩擦磨损性能、微观组织、表面硬度进行了对比研究,探讨了等温淬火处理对感应重熔镍基合金涂层摩擦学性能、微观组织、表面硬度的影响,揭示了其增强机理。结果经等温淬火后的重熔涂层比感应重熔涂层具有更低的摩擦系数和磨损失重,摩擦稳定阶段的摩擦系数为0.301,比后者低23.8%,相对耐磨性是后者的1.71倍。感应重熔涂层同时存在着磨粒磨损和粘着磨损两种机制,而经等温淬火后的重熔涂层以磨粒磨损为主,比前者具有更优异的抵抗磨粒磨损和粘着磨损的能力。感应重熔涂层及经等温淬火处理后的重熔涂层平均显微硬度分别为818.0、873.6HV(0.5),硬度极差分别为170.9、132.6HV(0.5),形状参数分别为18.5057、22.6189,后者比前者具有更高的平均硬度值、更小的硬度极差以及更加稳定的涂层性能。经过微观组织分析发现,重熔涂层在经等温淬火处理后,其晶粒的细化、硬质相的相对均质弥散性、共晶相的减少、丰富的耐磨陶瓷相和快速凝固的定向晶粒结构的协同作用,是其具有优异的显微硬度Weibull分布特性,以及耐磨性得到进一步提高的根本原因。结论合适的等温淬火热处理工艺能够改善感应重熔镍基合金涂层的微观组织,从而有效减小其摩擦系数,并提高其耐磨性。