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1.
The objective of this research is to prepare specially designed surface texture on hard steel surface by electrochemical micromachining (EM) and to incorporate electroless plated Ag/MoS2 solid lubricant coating into the dimples of EM textured steel surface to effectively reduce friction and wear of steel-steel contacts. The friction and wear behavior of the Ag/MoS2 solid lubricant coating on EM textured steel surface was evaluated in relation to the size and spacing of the dimples thereon. The microstructure of as-plated Ag/MoS2 solid lubricant coating and the morphology and elemental composition of the worn coating surface and counterface steel surface were analyzed by means of optical microscopy, scanning electron microscopy, and energy dispersive spectrometry. It is found that electroless plated Ag/MoS2 coating is able to greatly reduce the friction and wear of the EM textured steel disc coupled with GCr15 steel ring, mainly because of the formation of solid self-lubricating layer on the EM textured steel surface and of transferred lubricating film on counterface steel surface. The diameter and spacing of the dimples are suggested as 500 μm for acquiring the best wear resistance of the hard steel discs after electrochemical micromachining treatment and electroless plating of Ag/MoS2 solid lubricating coating. 相似文献
2.
Influence of nanometer lanthanum fluoride on friction and wear behaviors of bonded molybdenum disulfide solid lubricating films 总被引:1,自引:0,他引:1
Influence of nanometer lanthanum fluoride (nano-LaF3) on the friction and wear behavior of bonded molybdenum disulfide (MoS2) solid lubricating film was investigated using an oscillating friction-wear tester under dry friction condition. The worn surface of the lubricating film and the transfer film formed on the surface of the counterpart ball were observed by SEM. The microstructure of the lubricating film filled with nano-LaF3 and the distribution of F and La in the lubricating film were investigated with transmission electron microscopy (TEM) and field emission scanning electron microscope (FESEM) equipped with an energy dispersive X-ray spectrometer, respectively. It was found that nano-LaF3 as a filler contributes to improve the wear-resistance property of the lubricating film. The lubricating film modified with nano-LaF3 filler exhibits better wear-resistance property than that of the lubricating film without nano-LaF3 filler at a relatively lower load (less than 250 N) and within a wide oscillatory frequency range between 5 and 35 Hz. However, the incorporation of nano-LaF3 filler results in small increase of friction coefficient of the lubricating film. Transmission electron microscopy (TEM) and elementally X-ray map results of the lubricating film modified with nano-LaF3 filler indicate that partial LaF3 nanoparticles distribute around the MoS2 particles, while other LaF3 nanoparticles disperse in the binder. The SEM morphology of the frictional surface shows that the filler of nano-LaF3 is able to enhance the compactness of the frictional surface, and results in an improvement of the wear-resistance property of the MoS2 lubricating film. 相似文献
3.
Hongjian Guo Bo Li Minmin Han Wenyuan Chen Zhenyu Zhang Junhong Jia 《Journal of Materials Engineering and Performance》2018,27(8):3869-3876
In this work, the structural and mechanical properties, tribological performance, and lubrication mechanism from room temperature to 900 °C of TiN/MoS2/Ag composite films were investigated in detail. Nanostructured TiN/MoS2/Ag composite film was obtained by assembling targets using pulsed laser deposition. The incorporation of lubricant layered MoS2 and soft metal Ag led to degraded mechanical properties, which could contribute to the lower friction coefficients at low temperatures. When the temperature increased to above 500 °C, the generated high-temperature lubricant MoO3 and silver molybdates played a critical synergetic lubrication effect, which formed a layer of lubricating film and reduced the friction coefficient. Thus, the cooperation of various lubrication phases contributed to improvement of tribological performance and resulted in continuous lubrication from room temperature to 900 °C. 相似文献
4.
MoS2颗粒表面包覆Al2O3及其在镀层中的应用 总被引:1,自引:0,他引:1
采用非均匀形核法将Al2O3包覆到MoS2颗粒表面,提高颗粒的亲水性能。研究了溶液pH值、Al(NO3)3的摩尔浓度和预处理工艺对包覆率的影响;采用SEM及EDS分析了包覆前后MoS2颗粒的微观形貌和表面成分;通过测量接触角研究了颗粒表面的亲水性。结果表明,颗粒表面均匀包覆了一层Al(OH)3;溶液pH值对包覆率的影响最大,Al(NO3)3的摩尔浓度次之。最佳工艺为:溶液pH值为5.5,Al(NO3)3浓度为0.15mol/L,预处理过程不添加表面活性剂。随着包覆率的提高,MoS2颗粒的亲水性提高。利用包覆Al2O3的MoS2制得了Ni-P-MoS2化学复合镀层,提高了镀层中沉积粒子的均匀致密性。 相似文献
5.
为进一步提高爆炸喷涂WC-12Co涂层的耐磨性,在WC-12Co合金粉末中添加不同比例的MoS2粉末,利用爆炸喷涂技术在Q235钢表面制备了系列WC-12Co/MoS2复合涂层.采用金相显微镜、扫描电子显微镜、X射线衍射仪、显微硬度计及摩擦磨损试验机对WC-12Co/MoS2复合涂层的微观组织形貌、结构、显微硬度、摩擦磨损性能进行了研究.结果表明,MoS2均匀的分布于复合涂层中,当MoS2含量为2%时,复合涂层的硬度、致密度变化不大,但摩擦系数和磨损率大幅度下降,分别为WC-12Co涂层的50%和36%.随着MoS2含量的增加,复合涂层的摩擦系数和磨损率均呈上升趋势. 相似文献
6.
Qinglai Zhang Fugui Xiao Hailing Guo Changsheng Li Lin Gao Xingwu Guo Weidong Han A.B. Bondarev 《Journal of Materials Processing Technology》2010,210(2):323-329
The present study has been undertaken in order to investigate the suitable lubricants and lubricating methods, which can be employed to form a magnesium alloy AZ31 sheet by warm negative incremental forming (NIF). For the intended purpose, Nano-K2Ti4O9 whisker and organic binder were employed to improve the bonding strength at lubrication coating/sheet interface and lubricating properties at elevated temperatures. The Nano-K2Ti4O9 whisker enhanced solid lubrication film and the solid graphite or MoS2 powder-coated porous ceramic coatings by pulsed anodic oxidation (PAO) almost have the same coefficient of the initial friction about 0.07–0.1 at room and elevated temperatures, which was satisfied with friction and lubrication condition of warm incremental forming (IF) of the metal sheet. Solid graphite or MoS2 powder-coated ceramic coatings possessed the remarkable lubrication and self-lubrication effect. These suggested lubricating methods gave an excellent solid lubrication performance and good surface quality of the formed parts in warm IF process of the metal sheet. 相似文献
7.
《Surface & coatings technology》1999,111(2-3):123-127
A compound solid lubricating film containing a MoS2 top layer deposited on DLC interlayer by UBM sputtering technique was investigated for its tribological applications in humid environments. TEM, Raman and XRD analysis revealed the amorphous nature of the MoS2 film which contains only short-range order in its lattice structure. The as-deposited MoS2 compound films showed well-bonded interfaces. The MoS2, however, is very susceptible to humidity and oxidation, which resulted in higher friction coefficients and lower wear life. A friction coefficient of 0.05 was measured between steel balls and MoS2 in atmosphere of 90% RH. Excessive abrasive wear was identified, as a result of the wear debris and the oxidized transfer layers between MoS2 and its counterpart. The inclusion of a supportive DLC interlayer has effectively improved the wear behavior of MoS2 films under various loading conditions. The overall wear mechanism of MoS2 was complicated due to its oxidation problem which needs to be resolved for successful usage of MoS2 in humid environments. 相似文献
8.
Yinyin Zhang Sylvie Descartes Phuong Vo Richard R. Chromik 《Journal of Thermal Spray Technology》2016,25(3):473-482
Cu and Cu-MoS2 coatings were fabricated by cold spray, and the fretting wear performance of the two coatings was compared. A mixture (95 wt.% Cu + 5 wt.% MoS2) was used as feedstock for the composite coating. Coatings were sprayed with identical gas flow conditions on the substrates pre-heated to approximately 170 °C. The morphology of coating top surface and polished cross sections was analyzed by scanning electron microscopy (SEM) and light optical microscopy (LOM). The influence of MoS2 on Cu deposition was examined. The local MoS2 concentration within the coating was found to affect the hardness. Fretting tests were carried out at two different normal loads, and the influence of MoS2 on friction and wear was studied. The morphology and elemental compositions of the wear scars and wear debris were observed by SEM and energy dispersive x-ray spectroscopy (EDS), respectively. 相似文献
9.
Electroless Ni-P-PTFE-Al2O3 Dispersion Nanocomposite Coating for Corrosion and Wear Resistance 总被引:1,自引:0,他引:1
With the aim to produce a coating having good corrosion and wear resistance alongside hardness but lesser friction coefficient, Ni-P-PTFE-Al2O3 (NiPPA) dispersion coating was developed. This was achieved by introducing nanosized polytetrafluoroethylene (PTFE) and alumina (Al2O3) in the Ni-P matrix deposited on mild steel substrate. The coating was characterized using scanning electron microscopy, energy dispersive analysis of x-ray, and x-ray diffractrometry. Microhardness and wear resistance of the coating was measured using Vicker’s hardness tester and Pin-on-Disc method, respectively. The corrosion behavior was measured using electrochemical polarization and immersion tests with and without exposure in 3.5% NaCl solution. It is observed that codeposition of Al2O3 and PTFE particles with Ni-P coating results in comparatively smooth surface with nodular grains. The NiPPA coating was observed to have moderate hardness between electroless Ni-P-PTFE and Ni-P-Al2O3 coating and good wear resistance with lubricating effect. Addition of both PTFE and Al2O3 is observed to enhance corrosion resistance of the Ni-P coating. However, improvement in corrosion resistance is more due to addition of Al2O3 than PTFE. Continuous exposure for 10-20 days in corrosive solution is found to deteriorate corrosion protection properties of the coating. 相似文献
10.
Tomasz Moskalewicz Sławomir Zimowski Bogdan Wendler Piotr Nolbrzak Aleksandra Czyrska-Filemonowicz 《Metals and Materials International》2014,20(2):269-276
Duplex surface treatment, which combines the oxygen diffusion hardening with a deposition of low friction MoS2(Ti,W) coating, was applied to improve the Ti-6Al-4V alloy load bearing capacity and tribological properties. The coating (3.1 μm thick) was deposited on the oxygen hardened alloy by magnetron sputtering. Microstructure characterisation was performed by scanning- and transmission electron microscopy methods, as well as X-ray diffractometry. The results of micro/nanostructural analyses performed by high-resolution transmission electron microscopy showed that the coatings are composed of MoS2 nanoclusters embedded in an amorphous matrix. Some Ti α, W, and Ti2S nanocrystals were also found in the coating microstructure. The wear resistance and friction coefficient of the hardened oxygen, as well as the coated alloy, was investigated at room temperature (RT), 300 °C, and 350 °C. The presence of the MoS2(Ti,W) coating decreases the friction coefficient from 0.85 for the oxygen hardened alloy to 0.15 (at RT) and 0.09 (at 300 °C and 350 °C) for the coated one. The coating essentially increases the wear resistance of the alloy at RT and 300 °C. It was found that the wear resistance of the coated alloy decreased significantly during the wear test performed at 350 °C. 相似文献
11.
以大气等离子喷涂工艺制备的Al_2O_3陶瓷涂层为模板,利用陶瓷涂层中存在的孔隙和微裂纹,采用水热反应在其内部原位合成具有润滑特性的MoS_2,制备出Al_2O_3/MoS_2的复合涂层。结果表明,通过水热反应在陶瓷涂层原有的微观缺陷中成功合成了MoS_2,合成的MoS_2固体粉末呈类球形状,并且这球状的粉末是由纳米片层状的MoS_2搭建组成的。摩擦试验结果表明,与纯Al_2O_3涂层相比,复合涂层中由于MoS_2润滑膜的形成,其摩擦因数和磨损率都显著降低,且载荷越大,复合涂层的摩擦性能越好。 相似文献
12.
The microtribological properties of Au and Au-MoS2 coatings were examined using a nanoindentation instrument. MoS2 was chosen for this study as an additive to Au due to its positive influence on the mechanical and tribological properties. Reciprocating microscratch tests were performed using a diamond indenter with a tip radius of 50 μm and a range of normal loads between 0.2 mN and 5.0 mN. The friction and wear results, with respect to the two coatings, were correlated to different velocity accommodation modes and levels of adhesion. It was found that the addition of 20 mol% MoS2 to Au reduced the adhesion and limiting friction and also improved the wear resistance significantly. This coating shows potential for applications in microcomponents and microswitches due to its wear resistance, relatively low friction and good electrical conductivity. 相似文献
13.
Effect of MoSx content has been studied in TiN-MoSx composite coating deposited by closed-field unbalanced magnetron sputtering (CFUBMS) using separate MoS2 and Ti target in N2 gas environment. Pulsed dc power was applied for both the targets as well as for substrate biasing. Crystallographic orientation and structure of the coating was analysed by grazing incidence X-ray diffraction (GIXRD) technique. The surface morphology and coating fractograph were studied with field emission scanning electron microscopy (FESEM) whereas the composition of the coating was determined by energy dispersive spectroscopy (EDS) by X-ray. Scratch adhesion test, Vickers microhardness test and pin-on-disc test with cemented carbide (WC-6%Co) ball were carried out to investigate mechanical and tribological properties of the coating. Increase in MoSx content (from 6.22 wt.% to 30.43 wt.%) was found to be associated with decrease in grain size (from 63 nm to 24 nm). Maximum hardness of 32 GPa was obtained for TiN- MoSx composite coating. Film substrate adhesion was also observed to depend on MoSx content of the composite coating. Significant improvement in tribological properties was observed. With optimal MoSx content, it was possible to achieve low friction (µ = 0.02-0.04) and wear resistant (wear coefficient = 5.5 × 10− 16 m3/Nm) composite solid lubricant coating. 相似文献
14.
Cr2AlC coating was deposited at 370 and 500 °C by D.C. magnetron sputtering from an as-synthesized bulk Cr2AlC target. The phase composition and preferential orientation of the coating were investigated using XRD, and the microstructure of the coating was characterized by TEM. Results indicated that Cr2AlC coating with a strong (110) preferential orientation could be obtained. The coating microstructure was clearly affected by the deposition temperature. At 370 °C, the deposited coating possessed a triple-layered structure with an α-(Cr, Al)2O3 inner layer, an amorphous intermediate layer and a crystalline Cr2AlC outer layer. However, the coating deposited at 500 °C had a single-layered structure consisting of crystalline Cr2AlC layer. The growth mechanism of the Cr2AlC coating at different deposition temperatures is discussed. 相似文献
15.
The thin film deposition for tribological applications becomes more and more widespread. The tribological performance of the overlay coatings correlates with coating-substrate adhesion. Hence, it is important to measure adhesive strength. The scratch adhesion test for thin films is extensively used. In this work, MoS2-Nb coatings deposited by closed-field unbalanced magnetron sputtering (CFUBMS) have been scratch tested in two modes. A multi-mode operation was used as sliding-fatigue, like multi-pass scratching in the same track at different fractions of critical load (unidirectional sliding) and a standard mode using progressive load operation. Failure mechanisms are discussed according to examination of response of very dense microstructure and the adhesion value. The critical load to the first failure (LC1) was 15 N but the final adhesion value from the film and substrate interface was 120 N (LC2) as function of the coating thinning. The coefficient of friction (COF) from the multi-scratch for MoS2-Nb started at a very high value of around 0.067, 0.073, and 0.093 under 5, 8, and 15 N loads respectively and then drops to 0.006, 0.035, and 0.065 at the end of the 1000 cycles. The most significant finding in the test is that when the multi-scratch passes reached to 1000 cycles, micro scale fatigue failures disappeared. 相似文献
16.
Solid-lubricant MoS2 coatings have been successfully applied in high vacuum and aerospace environments. However, these coatings are very sensitive to water vapor and not suitable for applications in moist environments. In this work, Cr- and T-doped MoS2 composite coatings were developed. The results demonstrated that these composite coatings are promising for applications in high humidity environments.MoS2-Cr and MoS2-Ti composite coatings with different Cr or Ti content were deposited on high speed steel substrate by unbalanced magnetron sputtering. The composition, microstructure, and mechanical properties of the as-deposited MoS2-metal composite coatings were analyzed by energy dispersive analysis of X-ray (EDX), X-ray diffraction (XRD), and nanoindentation experiments. The tribological properties of the coatings were evaluated against an alumina ball under different relative humidity atmosphere using a ball-on-disc tribometer. The MoS2-Cr and MoS2-Ti coatings showed a maximum hardness of 7.5 GPa and 8.4 GPa at a dopant content of 16.6 at.% Cr or 20.2 at.% Ti, respectively. The tribological test results showed that, with a small amount of Cr and/or Ti doping, the tribological properties of MoS2 coatings under humid atmosphere could be significantly improved. The optimum doping level was found to be around 10 at.% for both MoS2-Cr coatings and MoS2-Ti coatings to show the best tribological properties, with both the lowest friction coefficient and wear rate. The excellent tribological properties of the MoS2-Cr and MoS2-Ti coatings with an appropriate metal doping level in moist atmosphere are found due to their ability to form stable transfer layer on the surface of the counterbody, which supplies lubrication for the contact surface. 相似文献
17.
This work reports on the tribological performance of three commercially available PTFE-based coatings (PTFE/pyrrolidone (C1), PTFE/pyrrolidone (C2) and PTFE/MoS2 (C3)) deposited onto engineered disk samples (substrates) made out of three different commonly used materials (gray cast iron, sintered iron and Al390-T6). Controlled oscillatory experiments were conducted to simulate the operating conditions of piston-type compressors in the presence of environmentally friendly CO2 refrigerant. It was found that the substrate played a major role on the tribological performance of the coatings and one of the coatings (PTFE/MoS2) was found to significantly improve the scuffing performance of Al390-T6 substrate. Furthermore, the tribological performance was found to improve with increasing CO2 pressure since a thicker patchy PTFE transfer layer was formed at the substrate-pin interface. XPS analysis showed that metal fluorides have a beneficial role on the tribological performance of these coatings. 相似文献
18.
电泳-电沉积 Ni-PTFE 复合镀层及其摩擦学行为研究 总被引:2,自引:1,他引:1
目的制备具有优良自润滑性能的Ni-PTFE复合镀层,同时探究其摩擦学性能。方法首先在铜基体表面电泳沉积一层PTFE膜,再将覆有PTFE膜的基体放入光亮镀镍溶液中进行电沉积(电泳-电沉积法),用SEM附带的能谱仪检测复合镀层的PTFE复合量,同时在自制的销盘摩擦磨损实验机上进行相关的摩擦学实验,以评价其摩擦学性能。结果用电泳-电沉积法制备出了含量(以体积分数计)达63.4%的Ni-PTFE复合镀层。在干摩擦条件下,PTFE微粒的加入可以降低复合镀层的摩擦系数(最低至0.067)。结论高PTFE复合量的复合镀层具有良好的耐磨性能。 相似文献
19.
Zhenhua Xu Shimei HeLimin He Rende MuGuanghong Huang Xueqiang Cao 《Journal of Alloys and Compounds》2011,509(11):4273-4283
Double-ceramic-layer (DCL) thermal barrier coatings (TBCs) of La2(Zr0.7Ce0.3)2O7 (LZ7C3) and yttria stabilized zirconia (YSZ) were deposited by electron beam-physical vapor deposition (EB-PVD). The thermal cycling test at 1373 K in an air furnace indicates the DCL coating has a much longer lifetime than the single layer LZ7C3 coating, and even longer than that of the single layer YSZ coating. The superior sintering-resistance of LZ7C3 coating, the similar thermal expansion behaviors of YSZ interlayer with LZ7C3 coating and thermally grown oxide (TGO) layer, and the unique growth modes of columns within DCL coating are all very helpful to the prolongation of thermal cycling life of DCL coating. The failure of DCL coating is mainly a result of the reduction-oxidation of cerium oxide, the crack initiation, propagation and extension, the abnormal oxidation of bond coat, the degradation of t′-phase in YSZ coating and the outward diffusion of Cr alloying element into LZ7C3 coating. 相似文献
20.
A. Shtertser C. Muders S. Veselov S. Zlobin V. Ulianitsky X. Jiang V. Bataev 《Surface & coatings technology》2012
Composite WC/Co + MoS2 coatings were deposited onto steel substrates by Computer Controlled Detonation Spraying using three spraying modes: very cold, cold and normal. Maximal content of MoS2 in a sprayed powder was 10 wt.%. Characterization of coatings was made with chemical and phase analyses, microhardness measurement, morphology and microstructure investigation. X-ray diffraction study shows that residual MoS2 exists only in coatings obtained at very cold and cold spraying modes. At normal spraying mode complete decomposition of the solid lubricant occurs during spraying. From the engineering point of view, the coating applied at the cold mode using a powder containing 10 wt.% MoS2 is the most promising. Such a coating has microhardness of 650 HV0.2 and a porosity of 10%. 相似文献