Effect of n-LaB4O7 Additive on Tribological Behaviors of Ion Nitrocarburized Layer at Higher Temperature

2015 ◽  
Vol 1120-1121 ◽  
pp. 249-253
Author(s):  
Chun Hua Hu ◽  
Jun Xue ◽  
Yun Kai Wang ◽  
Ya Zhi Li ◽  
Zhi Chang Deng

The paper studied the effect of n-LaB4O7additives of different contents on tribological behaviors of the ion nitrocarburized layer at higher temperature. It is found that 7% n-LaB4O7additives can improve obviously the tribological performances of the ion nitrocarburized layer. This because that synergetic effect of friction reduction and wear resistance is produced between the n-LaB4O7additives and ion nitrocarburized layer under higher temperature, load and frequence, and the solid lubrication films including oxide, nitride and sulphate and so on are formed on the friction surface to separate the contact between the metal sufaces, and furthermore the n-LaB4O7particles on the friction surface play the "Micron nanobearing" function, which make the ion nitrocarburized layer have the more excellent tribological performances.

2015 ◽  
Vol 1120-1121 ◽  
pp. 254-259
Author(s):  
Chun Hua Hu ◽  
Hai Jiang ◽  
Yun Feng Du ◽  
Hai Peng Wang ◽  
Zhi Chang Deng

The paper studied the effect of n-Na2B4O7additives of different content on tribological performances of the ion nitrocarburized layer. It is found that 7% n-Na2B4O7additive can improve greatly the friction reduction and wear resistance of the ion nitrocarburized layer under different conditions. This because that synergetic effect of friction reduction and wear resistance is produced between n-Na2B4O7additive and ion nitrocarburized layer under higher temperature, frequence and load, and the chemical reaction films including oxide, nitride, BN, and sulphide and so on formed on the friction surface play the solid lubrication function, and the n-Na2B4O7particles on the friction surface play the "Micron nanobearing" function, translating the sliding friction into the rolling friction, which can make the ion nitrocarburized layer possess the excellent tribological performances.


2014 ◽  
Vol 1004-1005 ◽  
pp. 1305-1310
Author(s):  
Chun Hua Hu ◽  
Zhi Chang Deng ◽  
Bao Shan Bian ◽  
Long Li ◽  
Hai Tao Wang

The paper studied the tribological performances of n-Na2B4O7/ion nitrocarburized duplex layer at different temperatures. It is found that the n-Na2B4O7/ion nitrocarburized duplex layer has more excellent friction reduction and wear resistance performances than the intermediate frequency quenched surface under CD15W-40 oil lubricating at different temperatures, especially at the higher temperature 100°C, the friction factor and volume loss of the duplex layer is 63% and 96% less than that of the intermediate frequency quenched surface respectively, which indicates that n-Na2B4O7/ion nitrocarburized duplex layer can play more excellent friction reduction, wear resistance and scuffing resistance performances at the relative higher temperature. This because that the chemical reaction films including oxide, BN and so on formed on the friction surface play the solid lubrication function, and the n-Na2B4O7 particles on the friction surface play the "Micron nanobearing" function.


2014 ◽  
Vol 1046 ◽  
pp. 62-67
Author(s):  
Chun Hua Hu ◽  
Jun Xue ◽  
Zhi Chang Deng ◽  
Shan Jun Wang ◽  
Hai Tao Wang

The paper studied the friction and wear performances of n-Na2B4O7/ion nitrocarburized duplex layer at different frequences. It is found that at frequence 10 Hz, 20 Hz, 30 Hz, respectively, the friction factor and volume loss of the duplex layer is 64%, 60%, 50% and 97%, 91%, 95% less than that of the intermediate frequency quenched surface, respectively, which indicates that the n-Na2B4O7/ion nitrocarburized duplex layer has more excellent friction reduction and wear resistance performances than the intermediate frequency quenched surface under CD15W-40 oil lubricating at different frequences. This because that the chemical reaction films including oxide, BN and so on formed on the friction surface play the solid lubrication function, and the n-Na2B4O7 particles on the friction surface play the "Micron nanobearing" function.


2013 ◽  
Vol 750-752 ◽  
pp. 389-392
Author(s):  
Chun Hua Hu ◽  
Feng Jun Qi ◽  
Meng Liang Lu ◽  
Guo Ning Wang ◽  
Qian Liu ◽  
...  

The paper studied that effect of temperature on tribological performances of ion nitrocarburized layer of 42MnCr52 steel under CD15W-40 oil lubricating. It is found that the ion nitrocarburized layer has more excellent friction reduction and wear resistance performances than the plain surface under different temperatures, especially under the higher temperature 150°C, the friction factor and wear scar width of ion nitrocarburized layer is 36% and 77% less than that of the plain surface respectively, which indicates that ion nitrocarburized layer can play more excellent friction reduction, wear resistance and scuffing resistance performances under the relative higher temperature.


2012 ◽  
Vol 502 ◽  
pp. 60-66 ◽  
Author(s):  
Chun Hua Hu ◽  
Jia Ping Zou ◽  
Jiu Juan Qian ◽  
Ding Yun Jin ◽  
Xiao Feng Sun

The composition of FeS solid lubrication duplex layer on 45 steel surface was studied by using SEM, EDS, AES and XPS. The results show that the sulphurized surface layer of FeS solid lubrication duplex is composed of the sulphide aggradation layer deposited on the nitrocarburized sub-surface layer and the sulphide diffusion layer formed by some S element infiltrating the nitrocarburized surface. The sulphide aggradation layer is mainly composed of FeS and FeS2, the key composition of the sulphide diffusion layer is FeS, and Fe(2/3/4)N is the key composition of the nitrocarburized sub-surface layer. The result of friction reduction and wear resistance test combined with the composition of FeS solid lubrication duplex layer explains that the friction coefficient and wear volume of the duplex layer are lower than those of the plain surface, which attribute to the relatively softer sulphurized surface layer provided self-lubricating property while the harder nitrocarburized sub-surface layer provided sufficient load bearing capacity in view of resistance to plastic deformation, so that spallation failure of the sulphurized surface layer can be effectively avoided, and they exert excellent friction reduction and wear resistance functions in different moments during rubbing process respectively.


2018 ◽  
Vol 70 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Shuwen Wang ◽  
Feiyan Yan ◽  
Ao Chen

Purpose The purpose of this paper is to investigate the tribological effects of laser surface texturing (LST) and residual stress on functional surfaces. Design/methodology/approach Three different surface textures (circular dimple, elliptical dimple and groove) with two different textured area ratios (10 and 20 per cent) are designed and fabricated by a Picosecond Nd YAG Laser machine. The friction and wear performance of textured specimens is tested using a UMT-2 friction and wear testing machine in mixed lubrication. Findings Test results show that elliptical dimples exhibit the best performance in wear resistance, circular dimples in friction reduction and grooves in stabilization of friction. The surfaces with larger textured area density exhibit better performance in both friction reduction and wear resistance. The improved performance of LST is the coupled effect of surface texture and residual stress. Originality/value The findings of this study may provide guidance for optimal design of functional surface textures in reciprocating sliding contacts under mixed or hydrodynamic lubrication, which can be used in automotive and other industrial applications.


2008 ◽  
Vol 587-588 ◽  
pp. 971-975 ◽  
Author(s):  
M. Buciumeanu ◽  
A.S. Miranda ◽  
F.S. Silva

The main objective of this work was to study the influence of the wear properties of two commercial alloys (CK45 and Al7175) on their fretting fatigue behavior. It is verified the effect of material local degradation by wear on a fatigue strength reduction factor, namely the stress concentration factor, and on the overall fretting fatigue life of these materials. The fretting fatigue phenomenon is a synergetic effect between wear and fatigue. It is dependent on both the fatigue and the wear properties of the materials. Material properties promoting an increase in wear resistance should enhance fretting fatigue life.


2008 ◽  
Vol 373-374 ◽  
pp. 476-479 ◽  
Author(s):  
C.H. Hu ◽  
Shi Ning Ma ◽  
Yu Lin Qiao ◽  
J.P. Zou ◽  
Y.D. Gao ◽  
...  

A new technology, duplex ion nitrocarburizing and sulphurizing technology (DINS), for friction reduction and anti-scuffing applications of diesel engine cylinder was studied. Duplex ion nitrocarburized-sulphurized layer was prepared on the surface of CrMoCu alloy cast iron by using the DINS process. The morphology, phase structure and tribological behaviors under sulphur contained additive lubrication were investigated. Results show that the sulphide surface layer of the duplex layer is mainly composed of close-packed hexagonal structured FeS phase and cubic structured FeS2 phase. The nitrocarburized sub-surface layer of the duplex layer is mainly composed of Fe2C and Fe3N phases. The harder nitrocarburized layer can provide effective support to the softer sulphide layer and avoid its lamellar tear. The synergistic effect between the duplex layer and the sulphur contained additive lubricant, resulted in 10% and 33.3% reduction in coefficient of friction and wear volume, respectively, compared with those of the sulphurized surface, and 25% and 50.1% reduction, respectively, compared with those of the plain surface. Bench test of diesel engine further demonstrated that the DINS process can provide the treated cylinder with superior properties in anti-scuffing and friction reduction, so that it can be used to prolong the service life of the cylinder.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xingxin Liang ◽  
Zhiyong Yang

Purpose This paper aims to confirm that increasing the hardness of thrust collars can improve the load carrying capacity (LCC) and wear resistance of water lubricated thrust bearings (WTBs) made of polymers paired with non-polymeric thrust collars, and to design a WTB with high LCC and durability for a shaftless pump-jet propulsor of an autonomous underwater vehicle. Six kinds of WTBs were manufactured by matching aluminum bronze, stainless steel and silicon nitride with two different polymer bearing materials. Their tribological behaviors were tested and compared. Design/methodology/approach The tribological behaviors of the WTBs made with different materials were investigated experimentally on a specially designed test rig. Findings Aluminum bronze is not suitable for crafting thrust collars of heavy load WTBs due to severe abrasive wear. Two body abrasive wear first occurred between the thrust collar and the polymer bearing. Next, aluminum bronze wear particles were produced. The particles acted between the two materials and formed three body abrasive wear. Stainless steel/polymer bearings showed better wear resistance while Si3N4/polymer bearings were the best. Improving the hardness of thrust collars is significant to the LCC and service life of WTBs. Originality/value The wear mechanism of WTBs under heavy load conditions was revealed. Improving the hardness of the thrust collar was confirmed to be a preferable method to improve the wear resistance and LCC of WTBs. The results of this study may provide an important reference for the selection of water lubricated materials and the design of heavy load WTBs.


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