scholarly journals Enhanced micro/nano-tribological performance in partially crystallized 60NiTi film

Friction ◽  
2020 ◽  
Author(s):  
Wanjun He ◽  
Qunfeng Zeng

Abstract The microstructure, mechanical and micro/nano-tribological properties of the 60NiTi film annealed at different temperature were investigated. The results reveal that annealing as-deposited 60NiTi film at 300, 375, and 600 °C for 1 h leads to structural relaxation, partial crystallization and full crystallization, respectively. Compared with the structurally relaxed structure, the partially crystallized structure exhibits increased hardness but decreased elastic modulus. This is because that the elastic modulus is reduced by Voigt model while the hardness is improved by composite effect. Due to the highest hardness and ratio of hardness to elastic modulus (H/E), the partially crystallized 60NiTi film has the lowest penetration depth and residual depth (i.e., groove depth). Besides, the results also reveal that ductile plowing is the dominant wear mechanism for all the annealed 60NiTi films. Under the condition of the ductile plowing, coefficient of friction and wear resistance are related to penetration depth and residual depth, respectively. Therefore, the partially crystallized 60NiTi film shows the best tribological performance at the micro/nano-scale. The current work not only highlights the important roles of hardness and H/E in improving the micro/nano-tribological properties but also concludes an efficient and simple method for simultaneously increasing hardness and H/E.

2013 ◽  
Vol 645 ◽  
pp. 133-136
Author(s):  
Peng Qiao ◽  
Yan Qiu Xia ◽  
Xiang Yu Ge

Overbased calcium sulfonate complex greases have excellent friction and wear properties and have been widely used in metallurgy and mining equipment. The effects and tribological performance of molybdenum dialkydithiocarbamate (MoDTC) and ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([C2OHMim][NTf2]), 1-(2-hydroxyethyl)-3-hexylimidazolium bis (trifluoromethylsulfonyl) imide ([C2OHHim][NTf2s]), added in overbased calcium sulfonate complex grease as additives were investigated by using reciprocating ball-on-disk sliding friction tester. The results showed that the two kinds of additives with a certain range of concentration could improve the tribological properties of greases.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Haizhong Wang ◽  
Zenghong Song ◽  
Dan Qiao ◽  
Dapeng Feng ◽  
Jinjun Lu

The tribological performance of Si3N4ball sliding against Ti3SiC2disc lubricated by lithium-based ionic liquids (ILs) was investigated using an Optimol SRV-IV oscillating reciprocating friction and wear tester at room temperature (RT) and elevated temperature (100°C). Glycerol and the conventional imidazolium-based IL 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (L-F106) were used as references under the same experimental conditions. The results show that the lithium-based ILs had higher thermal stabilities than glycerol and lower costs associated with IL preparation than L-F106. The tribotest results show that the lithium-based ILs were effective in reducing the friction and wear of Si3N4/Ti3SiC2contacts. [Li(urea)]TFSI even produced better tribological properties than glycerol and L-F106 both at RT and 100°C. The SEM/EDS and XPS results reveal that the excellent tribological endurance of Si3N4/Ti3SiC2contacts lubricated by lithium-based ILs was mainly attributed to the formation of surface protective films composed of various tribochemical products.


2011 ◽  
Vol 284-286 ◽  
pp. 2370-2373 ◽  
Author(s):  
Jian Li

The effects of PTFE on the tensile and tribological properties of glass fiber reinforced polyamide 6(PA6) composites were studied. Tribological tests were conducted on an M2000 friction and wear tester using a block-on-ring arrangement. It was observed that the PTFE played a main role in the tensile-resistant and wear-resistant properties of the PA6 composites. The tensile properties were ruled by the fiber–matrix adhesion. And the excellent tribological performance of the PTFE fillers improved the tribological properties of PA6 composites.


2010 ◽  
Vol 150-151 ◽  
pp. 655-658
Author(s):  
Ting Xie ◽  
Gang Chen ◽  
Yan Guo Yin ◽  
Ming Hua Jiao ◽  
Jian Wei Yu ◽  
...  

Due to the poor thermal conduction of polytetrafluoroethylene (PTFE), some fillers are often added into PTFE matrix to improve its thermal conduction and enhance its tribological performance. In our work, to increase their thermal conduction, the PTFE composites with different contents of copper particles were prepared. The friction and wear properties of the composites were tested. The effect of thermal conduction on tribological properties of the PTFE based composites was analyzed, and the wear mechanisms were also discussed. The results showed that with the increase of the thermal conductivity of the PTFE based composites, the coefficient of friction of the materials reduced, and the wear of the materials was dramatically decreased.


2014 ◽  
Vol 81 (12) ◽  
Author(s):  
Nay Win Khun ◽  
He Zhang ◽  
Xiu-zhi Tang ◽  
Chee Yoon Yue ◽  
Jinglei Yang

The effects of wax lubricant filled microcapsule content on the tribological properties of epoxy composites without or with 8 wt.% short carbon fibers (SCFs) were systematically investigated. The core percentage of the microcapsules used in this study was about 70 wt.%. The tribological results clearly showed that the friction and wear of the epoxy composites without or with SCFs tested against a 6 mm steel ball significantly decreased with increased microcapsule content from 2.5 to 10 wt.% as a result of the increased amount of released wax lubricant to lubricate rubbing surfaces. The epoxy composites with 8 wt.% SCFs exhibited the lower friction and wear than the ones without SCFs due to the combined lubricating effects of SCFs and released wax lubricant and the improved mechanical strength of the composites. It can be concluded that the higher microcapsule content gives rise to the lower friction and wear of the epoxy composites as the epoxy composites with 8 wt.% SCFs have the better tribological performance than the ones without SCFs.


Author(s):  
Waleed Al-Sallami ◽  
Pourya Parsaeian ◽  
Abdel Dorgham ◽  
Anne Neville

Trihexyltetradecylphosphonium bis(2-ethylhexyl)phosphate (phosphonium phosphate) ionic liquid is soluble in non-polar lubricants. It has been proposed as an effective anti-wear additive comparable to zinc dialkyldithiophosphate. Previously, phosphonium phosphate has shown a better anti-wear performance under some conditions such as high temperature. In this work, the tribological performance and the lubrication mechanism of phosphonium phosphate are compared with that of zinc dialkyldithiophosphate when lubricating silicon under various tribological conditions. This can lead to an understanding of the reasons behind the superior anti-wear performance of phosphonium phosphate under some conditions. A micro-scale study is conducted using a nanotribometer. The results show that both additives lead to a considerable reduction in both friction and wear coefficients. The reduction in the wear coefficient is mainly controlled by the formation of the tribofilm on the rubbing surfaces. Zinc dialkyldithiophosphate can create a thicker tribofilm, which results in a better anti-wear performance. However, the formation of a thicker film will lead to a faster depletion and thus phosphonium phosphate can provide better anti-wear performance when the depletion of zinc dialkyldithiophosphate starts.


2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.


2014 ◽  
Vol 81 (7) ◽  
Author(s):  
N. W. Khun ◽  
H. Zhang ◽  
C. Y. Yue ◽  
J. L. Yang

Self-lubricating and wear resistant epoxy composites were developed via incorporation of wax-containing microcapsules. The effects of microcapsule size and content and working parameters on the tribological properties of epoxy composites were systematically investigated. The incorporation of microcapsules dramatically decreased the friction and wear of the composites from those of the epoxy. The increased microcapsule content or the incorporation of larger microcapsules decreased the friction and wear of the epoxy composites due to the larger amount of released wax lubricant via the rupture of microcapsules during the wear test. The friction of the composites decreased with increased normal load as a result of the promoted wear of the composites and the increased release of the wax lubricant.


2012 ◽  
Vol 504-506 ◽  
pp. 969-974 ◽  
Author(s):  
Harald Hetzner ◽  
Stephan Tremmel ◽  
Sandro Wartzack

In sheet bulk metal forming, locally adapted friction properties of the contact tool/workpiece are an appropriate means for the targeted enhancement of the material flow, enabling an improved form filling and lowered forming forces. However, the implementation of desirable friction conditions is not trivial. And further, friction is inseparably linked to wear and damage of the contacting surfaces. This calls for a methodological approach in order to consider tribology as a whole already in the early phases of process layout, so that tribological measures which allow fulfilling the requirements concerning local friction and wear properties of the tool surfaces, can already be selected during the conceptual design of the forming tools. Thin tribological coatings are an effective way of improving the friction and wear properties of functional surfaces. Metal-modified amorphous carbon coatings, which are still rather new to the field of metal forming, allow tackling friction and wear simultaneously. Unlike many other types of amorphous carbon, they have the mechanical toughness to be used in sheet bulk metal forming, and at the same time their friction properties can be varied over wide ranges by proper choice of the deposition parameters. Based on concrete research results, the mechanical, structural and special tribological properties of tungsten-modified hydrogenated amorphous carbon coatings (a-C:H:W) are presented and discussed against the background of the tribological requirements of a typical sheet bulk metal forming process.


1994 ◽  
Vol 9 (11) ◽  
pp. 2823-2838 ◽  
Author(s):  
B.K. Gupta ◽  
Bharat Bhushan ◽  
C. Capp ◽  
J.V. Coe

In previous studies, sublimed C60-rich fullerene films on silicon, when slid against a 52100 steel ball under dry conditions, have exhibited low coefficient of friction (∼0.12). Films with different purities can be produced by sublimation at different substrate temperatures. In this paper, effects of purity of fullerene films and ion implantation of the films with Ar ions on the friction and wear properties of sublimed fullerene films are reported. C60-rich films (called here films with high purity) exhibit low macroscale friction. An increased amount of C70 and impurities in the fullerene film determined using Raman and Fourier transform infrared (FTIR), increases its coefficient of friction. Microscale friction measurements using friction force microscopy also exhibited similar trends. Low coefficient of friction of sublimed C60-rich films on silicon is probably due to the formation of a tenacious transfer film of C60 molecules on the mating 52100 steel ball surface. Based on scanning tunneling microscopy (STM), transmission electron microscopy (TEM), and high resolution TEM (HRTEM), we found that fullerene films primarily consisted of C60 molecules in a fcc lattice structure. Nanoindenter was used to measure hardness and elastic modulus of the as-deposited films. Ion-implantation with 1 × 1016 Ar+ cm−2 reduced macroscale friction down to about 0.10 from 0.12 with an increase in wear life by a factor of 4; however, doses of 5 × 1016 ions cm−2 gave three times higher friction and poorer wear life; higher doses disintegrated the C60 molecules. Based on STM, TEM, Raman, FTIR, and laser desorption Fourier-transform ion cyclotron resonance mass spectrometer (LD/FT/ICR) studies, we found that the ion implantation with a dose of 1 × 1016 Ar+ cm−2 resulted in smoothening of the fullerene film surface probably by compacting clusters, but without disintegrating the C60 molecules. However, a high dose of 5 × 1016 Ar+ cm−2 damaged the C60 molecules, converting it to an amorphous carbon. Nanoindentation studies show that ion implantation with a dose of 1 × 1016 Ar+ cm−2 resulted in an increase in the hardness from about 1.2 to 4.0 GPa and in elastic modulus from about 70 to 75 GPa and modified the elastic-plastic deformation behavior.


Sign in / Sign up

Export Citation Format

Share Document