Tribological and Corrosion Behavior of HVOF Sprayed Cr3C2-NiCr with Nickel Cladded Graphite and Hexagonal Boron Nitride

Author(s):  
M. Oechsner ◽  
T. Engler ◽  
H. Scheerer ◽  
Y. Joung ◽  
K. Bobzin ◽  
...  

Abstract High-velocity oxyfuel (HVOF) sprayed coatings of Cr3C2-NiCr containing solid lubricants such as nickel cladded graphite and hexagonal boron nitride were successfully developed and characterised with the aim of optimizing their friction and wear behaviour. HVOF technology was used for the integration of solid lubricants to achieve strong cohesion between particles while minimizing thermal decomposition. Coating microstructure and composition were measured and correlated to the results of tribological and corrosion tests. The integration of the solid lubricant greatly reduced friction and wear volume at room temperature, but the lubricating effect was highly dependent on atmosphere and temperature. Cr3C2-NiCr with hBN, however, tends to exhibit more stable wear resistance over a wider temperature range and can be used at temperatures beyond 450 °C.

2011 ◽  
Vol 697-698 ◽  
pp. 80-83
Author(s):  
L.Y. Ding ◽  
Hong Hua Su ◽  
H.J. Xu ◽  
M. Fan

It is essential to control the heat generated in the cutting zone in order to ensure the workpiece quality after grinding. This article deals with an investigation in using graphite and hexagonal boron nitride as solid lubricants to reduce friction and thereby improve the surface integrity of Ti-6Al-4V alloy. The polymer-based solid lubricant coating wheels have been prepared. Grinding experiments have been conducted to study the effect of the graphite and hexagonal boron nitride lubricants on the grinding temperature and the surface quality of the workpiece while grinding Ti-6Al-4V. Results indicate that there is a considerable improvement in the performance of grinding Ti-6Al-4V using graphite and hexagonal boron nitride as solid lubricants in dry grinding in terms of grinding temperature and surface quality of the work piece. The indigenous polymer-based solid lubricant coatings are effective in dry grinding.


Author(s):  
R Westergård ◽  
A Åhlin ◽  
N Axén ◽  
S Hogmark

The friction and wear behaviour of a series of new Si3N4-SiC-based ceramic composites, intended for face seal applications, has been investigated with cylinder-on-disc equipment. In particular, the influence of water and vapour on the friction, wear and tribo-film formation has been studied. The ceramics consisted of Sis3N4 and SiC in the proportions 7:3, to which 0, 4 or 8 wt% of hexagonal boron nitride was added as a solid lubricant. All specimens were produced by hot isostatic pressing. X-ray diffraction and scanning electron microscopy were used to reveal the phase composition and microstructure respectively. The hardness was assessed using Vickers indentation. The chemical composition of the tribo-films was studied with X-ray photoelectron spectroscopy. The major results are that both friction and wear showed distinct low and high levels. The high friction level corresponded to friction coefficients between 0.4 and 0.9 and wear rates between 104 and 105 μm3/Nm. The low level corresponded to friction coefficients between 0.02 and 0.1, and wear rates between 10 and 103 μm3/Nm. When water or saturated vapour was present in the tribo-system, both friction and wear were low. All surfaces produced in the low level were smooth, covered by a thin well-adhering tribo-film while the high level resulted in strongly oxidized and patchy tribo-film covered by wear particles.


2017 ◽  
Vol 890 ◽  
pp. 98-102 ◽  
Author(s):  
Sourabh Paul ◽  
Amitava Ghosh

Small quantity cooling lubrication (SQCL) with commercially available metal working fluids (MWF) and nanofluids has been attempted successfully in machining and grinding. Solid lubricants also provided some benefits in grinding of metallic alloys. However, there are very few studies using molybdenum di-sulphide (MoS2) and hexagonal boron nitride (hBN) dispersed nanofluids applied in SQCL mode in grinding. The aim of the present work is to experimentally study improvement in grinding of EN31 steel using alumina grinding wheel with aqueous MoS2 and hBN nanofluids. The grinding study is supported by detailed tribometry at 1 m/s sliding speed to reveal the possible reasons behind such improvement. MoS2 dispersed nanofluids provided minimum coefficient of friction in ball-on-disc test. It also provided the maximum reduction in specific grinding energy and improvement in surface finish with respect to flood cooling. hBN dispersed nanofluids could not match the performance of MoS2 dispersed nanofluids both in ball-on-disc and grinding experiments.


2017 ◽  
Vol 69 (5) ◽  
pp. 715-722 ◽  
Author(s):  
Sanjay Mohan Sharma ◽  
Ankush Anand

Purpose This paper aims to investigate the effect of CaF2 (calcium fluoride) addition as a solid lubricant on the friction and wear behaviour of sintered Fe-Cu-C materials under different loads. Design/methodology/approach In this study, the effects of CaF2 added in varying weight percentages on the friction-wear properties of Fe-2Cu-0.8C alloys are investigated. Five Fe-2Cu-0.8C-based compositions comprising CaF2 in 0, 3, 6, 9 and 12 Wt.% were prepared using the single-stage compaction and sintering technique. Friction coefficient, wear loss, hardness and compressive strength of the specimens were measured. The worn-out surfaces were analysed using a scanning electron microscope. Friction and wear tests were carried out on pin-on-disc machine under dry sliding conditions at room temperature. Findings The alloy with 3 Wt.% CaF2 was found to be useful in improving wear and friction properties, whereas higher contents of CaF2 resulted in increased wear and friction. Apart from enhanced tribological properties, a slight decrease in the compressive strength was also observed in the 3-Wt.%-CaF2-added sample. Adhesion and abrasion were the prominent wear types observed during this study. Originality/value A new self-lubricating composite is developed where CaF2 is used as a solid lubricant in a Fe-Cu-C-based matrix. CaF2, being a high-temperature lubricant, is tried and tested for friction and wear at room temperature, and the results show that the addition of CaF2 in Fe-Cu-C improved its friction and wear properties. Thus, the developed material can be used for antifriction applications.


2016 ◽  
Vol 4 (37) ◽  
pp. 8711-8715 ◽  
Author(s):  
Muhammad Zahir Iqbal ◽  
Salma Siddique ◽  
Ghulam Hussain ◽  
Muhammad Waqas Iqbal

Graphene and hexagonal boron nitride (hBN) have shown fascinating features in spintronics due to their metallic and tunneling behaviors, respectively. In this work, we report for the first time room temperature spin valve effect in NiFe/Gr–hBN/Co configuration.


Wear ◽  
1973 ◽  
Vol 24 (3) ◽  
pp. 261-278 ◽  
Author(s):  
D.S. Lin ◽  
F.H. Stott ◽  
G.C. Wood ◽  
K.W. Wright ◽  
J.H. Allen

Author(s):  
A. Vanhulsel ◽  
R. Jacobs ◽  
K. Van Acker ◽  
E. Roberts ◽  
F. Velasco ◽  
...  

The development of advanced solid lubricants is of considerable importance to space tribology. The most common solid lubricant coatings today are based on MoS2, lead or PTFE. However, none of these coatings can simultaneously fulfill all specifications, with regard to friction and wear, under ambient atmosphere and in vacuum. Consequently research is currently being aimed at further improvements in advanced solid lubricant coatings. One approach is to optimize Diamond Like Carbon (DLC) coatings to meet the specifications. In this study, the feasibility of highly hydrogenated DLC coatings (∼ 50 at% hydrogen) for solid lubricant applications is assessed. The coatings were deposited on AISI 52100 steel substrates and tested in ball-on-disc tribometers in air, vacuum and dry nitrogen environments. It was found that the test environment has the most decisive effect on both friction and wear rate, while these parameters are only slightly affected by varying the applied load under a given atmosphere. It was concluded that highly hydrogenated DLC coatings are capable of yielding ultra-low friction values in vacuum (μ = 0.008). The average friction coefficient range obtained in humid air, dry nitrogen and vacuum for the range of applied loads were respectively 0.22 to 0.27, 0.02 to 0.03, and 0.007 to 0.013. Coating lifetime was over 100 000 cycles for the entire load range tested in air and nitrogen, but was affected by the applied load as far as tests in vacuum are considered. The specific wear rate was lower than 1×10–5 mm3 N-1 m-1 under all test conditions, which was considered favourable.


2021 ◽  
pp. 67-70
Author(s):  

The effect of a solid lubricant on the wear of cubic boron nitride grinding wheels on a ceramic bond of different hardness and grain size in the processing of high-speed steel is investigated. The dependences of the change in the wear of cubic boron nitride on the parameters of the processing mode are determined. An automated calculation system is proposed to control the consumption of cubic boron nitride grinding wheels in production conditions. Keywords: solid lubricant, grinding, high speed steel, cubic boron nitride grinding wheel, consumption, wear, grinding mode. [email protected]


Author(s):  
Jianliang Li ◽  
Dangsheng Xiong ◽  
Yongkun Qin ◽  
Rajnesh Tyagi

This chapter illustrates the effect of the addition of solid lubricants on the high temperature friction and wear behavior of Ni-based composites. Ni-based composites containing solid lubricant particles both in nano and micrometer range have been fabricated through powder metallurgy route. In order to explore the possible synergetic action of a combination of low and high temperature solid lubricant, nano or micro powders of two or more solid lubricants were added in the composites. This chapter introduces the fabrication of the Ni-based self-lubricating composites containing graphite and/or MoS2, Ag and/or rare earth, Ag and/or hBN as solid lubricants and their friction and wear behavior at room and elevated temperatures. The chapter also includes information on some lubricating composite coatings such as electro-deposited nickel-base coating containing graphite, MoS2, or BN and graphene and their tribological characteristics.


2013 ◽  
Vol 652-654 ◽  
pp. 1904-1907 ◽  
Author(s):  
Suo Xia Hou ◽  
Hui Gao ◽  
Xiao Ming Jia

WS2has excellent tribological properties; it is emerging of lubricating materials. MoS2is commonly used solid lubricants and wide range of applications, but its poor heat resistance. WS2can well make up for the inadequate performance of the MoS2, but uses it as a solid lubricant in performance research on metallic materials. By friction and wear testing, the paper gets feasibility analysis of the application that WS2instead of MoS2in the field of solid lubrication, while exploring the synergies between them, laying the foundations for the manufacture of new types of composite lubrication coatings.


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