Enhancing the Tribological Properties and Corrosion Resistance of Graphene-Based Lubricating Grease via Ultrasonic-Assisted Ball Milling

The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives.

Download Full-text

Structure, Corrosion Resistance, Mechanical and Tribological Properties of ZrB2 and Zr-B-N Coatings

Metals ◽

10.3390/met11081194 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1194

Author(s):

Philipp Kiryukhantsev-Korneev ◽

Alina Sytchenko ◽

Yuriy Kaplanskii ◽

Alexander Sheveyko ◽

Stepan Vorotilo ◽

...

Keyword(s):

Corrosion Resistance ◽

Tribological Properties ◽

Current Density ◽

Corrosion Current Density ◽

Elastic Recovery ◽

Optical Emission ◽

Corrosion Current ◽

Impact Testing ◽

Total Oxidation ◽

Mechanical And Tribological Properties

The coatings ZrB2 and Zr-B-N were deposited by magnetron sputtering of ZrB2 target in Ar and Ar–15%N2 atmospheres. The structure and properties of the coatings were investigated via scanning and transmission electron microscopy, energy dispersion analysis, optical profilometry, glowing discharge optical emission spectroscopy and X-ray diffraction analysis. Mechanical and tribological properties of the coatings were investigated using nanoindentation, “pin-on-disc” tribological testing and “ball-on-plate” impact testing. Free corrosion potential and corrosion current density were measured by electrochemical testing in 1N H2SO4 and 3.5%NaCl solutions. The oxidation resistance of the coatings was investigated in the 600–800 °С temperature interval. The coatings deposited in Ar contained 4–11 nm grains of the h-ZrB2 phase along with free boron. Nitrogen-containing coatings consisted of finer crystals (1–4 nm) of h-ZrB2, separated by interlayers of amorphous a-BN. Both types of coatings featured hardness of 22–23 GPa; however, the introduction of nitrogen decreased the coating’s elastic modulus from 342 to 266 GPa and increased the elastic recovery from 62 to 72%, which enhanced the wear resistance of the coatings. N-doped coatings demonstrated a relatively low friction coefficient of 0.4 and a specific wear rate of ~1.3 × 10−6 mm3N−1m−1. Electrochemical investigations revealed that the introduction of nitrogen into the coatings resulted in the decrease of corrosion current density in 3.5% NaCl and 1N H2SO4 solution up to 3.5 and 5 times, correspondingly. The superior corrosion resistance of Zr-В-N coatings was related to the finer grains size and increased volume of the BN phase. The samples ZrB2 and Zr-B-N resisted oxidation at 600 °C. N-free coatings resisted oxidation (up to 800 °С) and the diffusion of metallic elements from the substrate better. In contrast, Zr-B-N coatings experienced total oxidation and formed loose oxide layers, which could be easily removed from the substrate.

Download Full-text

Improving the adhesive, mechanical, tribological properties and corrosion resistance of reactive sputtered tantalum oxide coating on Ti6Al4V alloy via introducing multiple interlayers

Ceramics International ◽

10.1016/j.ceramint.2021.11.134 ◽

2021 ◽

Author(s):

Ziyu Ding ◽

Yinghong Tang ◽

Lei Liu ◽

Zeliang Ding ◽

Yimin Tan ◽

...

Keyword(s):

Corrosion Resistance ◽

Tribological Properties ◽

Tantalum Oxide ◽

Oxide Coating ◽

Ti6al4v Alloy

Download Full-text

Tribological properties of beef tallow as lubricating grease

Industrial Lubrication and Tribology ◽

10.1108/ilt-01-2016-0014 ◽

2017 ◽

Vol 69 (5) ◽

pp. 645-654 ◽

Cited By ~ 2

Author(s):

Juozas Padgurskas ◽

Raimundas Rukuiža ◽

Ihor Mandziuk ◽

Arturas Kupcinskas ◽

Katerina Prisyazhna ◽

...

Keyword(s):

Critical Load ◽

Tribological Properties ◽

Beef Tallow ◽

Friction And Wear ◽

Load Level ◽

Synthesis Process ◽

Polymer Additives ◽

Lubricating Grease ◽

Content Type ◽

Thermally Processed

Purpose The purpose of this paper is to report on the tribological properties of beef tallow grease and improvements therein through modification with special processing, polymeric compounds and additives. Design/methodology/approach Pure original beef tallow grease was used as a biological lubricating grease reference material for the tribological research. Beef tallow was modified and synthesized by adding special biological anti-oxidant additives, LZ anti-wear additives, waste polyethylene terephthalate (PET) polymer compounds and thermally processed graphite. Findings Rheometric measurements indicate that the beef tallow grease modification technology used in this study enables control of the synthesis process to produce lubricants with the required microstructure. Investigation results of the tribological properties of differently modified greases show that beef tallow synthesized with polymer additives efficiently operates together with anti-wear additives to reduce friction and wear. The grease compound with thermally processed graphite has good tribological properties at 300 N load levels. The critical load level of lubricating greases could be significantly increased through the use of anti-wear additives and thermally processed graphite. Originality/value Investigation results of the tribological properties of differently modified beef tallow greases show that beef tallow synthesized with polymer additives efficiently operates together with anti-wear additives to reduce friction and wear. The critical load level of lubricating beef tallow greases could be significantly increased using anti-wear additives and thermally processed graphite.

Download Full-text

Electroless Nickel-Phosphorus Composite Coatings

International Journal of Manufacturing Materials and Mechanical Engineering ◽

10.4018/ijmmme.2016010102 ◽

2016 ◽

Vol 6 (1) ◽

pp. 14-50 ◽

Cited By ~ 4

Author(s):

Prasanna Gadhari ◽

Prasanta Sahoo

Keyword(s):

Corrosion Resistance ◽

Tribological Properties ◽

Composite Coatings ◽

Electroless Nickel ◽

Friction Behavior ◽

Factors Affecting ◽

Conductive Materials ◽

Mechanical And Tribological Properties ◽

Coating Methods ◽

Soft Particles

Electroless nickel composite coatings possess excellent mechanical and tribological properties such as, hardness, wear and corrosion resistance. Composite coatings can easily be coated not only on electrically conductive materials but also on non-conductive materials like as fabrics, plastics, rubber, etc. This review emphasizes on the development of electroless nickel composite coatings by incorporating different types of hard/soft particles (micro/nano size) in the electroless Ni-P matrix to improve the mechanical and tribological properties of the coatings. The preparation of electroless bath for nickel-phosphorus composite coating, methods to incorporate hard and/or soft particles in the bath, factors affecting the particle incorporation in the coating and its effect on coating structure, hardness, wear resistance, friction behavior, corrosion resistance, and mechanical properties are discussed thoroughly.

Download Full-text

Effect of different post-treatments on the corrosion resistance and tribological properties of AZ91D magnesium alloy coated PEO

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2015.07.017 ◽

2015 ◽

Vol 278 ◽

pp. 99-107 ◽

Cited By ~ 32

Author(s):

A. Castellanos ◽

A. Altube ◽

J.M. Vega ◽

E. García-Lecina ◽

J.A. Díez ◽

...

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Tribological Properties ◽

Az91d Magnesium Alloy

Download Full-text

MICROSTRUCTURE AND ELECTROCHEMICAL PROPERTIES OF Ni–B/GO ULTRASONIC-ASSISTED COMPOSITE COATINGS

Surface Review and Letters ◽

10.1142/s0218625x1950080x ◽

2019 ◽

Vol 26 (10) ◽

pp. 1950080

Author(s):

JIBO JIANG ◽

HAOTIAN CHEN ◽

LIYING ZHU ◽

YAOXIN SUN ◽

WEI QIAN ◽

...

Keyword(s):

Corrosion Resistance ◽

Photoelectron Spectroscopy ◽

Electrochemical Impedance ◽

Composite Coatings ◽

Ultrasonic Field ◽

Protective Material ◽

X Ray ◽

Electrochemical Tests ◽

Ultrasonic Assisted ◽

Corrosive Environments

Graphene oxide (GO) sheet and ultrasonic field (UF) were successfully employed to produce Ni–B/GO and UF–Ni–B/GO composite coatings on Q235 mild steel by electroless plating. The composite coatings’ structure and surface morphology were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Results showed that GO was successfully co-deposited in the Ni–B alloy. Moreover, UF–Ni–B/GO composite coatings have smoother surface and thicker cross-section than others. The microhardness and corrosion resistance of the sample coatings were determined using Vickers hardness tests, Tafel electrochemical tests and electrochemical impedance measurements (EIS) in 3.5[Formula: see text]wt.% NaCl solution to receive the effect of GO and ultrasonic. The findings indicated that UF–Ni–B/GO exhibited optimum hardness (856[Formula: see text]HV) and enhanced corrosion resistance (6.38 [Formula: see text][Formula: see text] over the Ni–B and Ni–B/GO coatings. Due to these interesting properties of the coating, it could be used as a protective material in the automotive and aerospace industries for parts of machines that were manipulated in high temperature and corrosive environments.

Download Full-text

Influence of the Organic Additions on Structure, Corrosion Resistance and Tribological Properties of Ni/Al2O3 Composite Coatings

Materials Science Forum ◽

10.4028/www.scientific.net/msf.765.663 ◽

2013 ◽

Vol 765 ◽

pp. 663-667

Author(s):

Marek Nowak ◽

Mieczysław Opyrchał ◽

Sonia Boczkal ◽

Janusz Żelechowski

Keyword(s):

Corrosion Resistance ◽

Tribological Properties ◽

Composite Coatings ◽

Electrochemical Behaviour ◽

Wear Test ◽

Standard Test ◽

Properties Of Coatings ◽

Corrosion Properties ◽

X Ray ◽

Xrd Techniques

Composite Ni/Al2O3 coatings were electrochemically deposited from a Watts bath modified with the organic additions of dioctyl sulphosuccinate sodium salt C20H37NaO7S–(DSS) and 2,3-dihydroxy-1,2 benzisothiazol-3-one 1,1-dioxide C7H5NO3–(LSA). The effect of different amount (50 and 100 g/l) of Al2O3 powder and organic additions on microstructure, microhardness, corrosion resistance and tribological properties was investigated. The coatings were examined by optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) techniques. The electrochemical behaviour of the coatings in corrosive solutions (1 M NaCl and 1 M Na2SO4) was investigated by potentiodynamic polarisation. The tribological properties were investigated by the Taber abrasive wear test, a standard test often applied in industrial practice. The results show that Al2O3 particles are uniformly distributed in the composite coatings compared with coatings without organic additions. The addition of organic compounds also reduced the size of the forming nickel crystallites and improved the tribological and corrosion properties of coatings containing the dispersed hard particles of Al2O3 added in an amount of 50 g/l and the addition of organic LSA and DSS compounds.

Download Full-text