scholarly journals Tribology Properties of Synthesized Multiscale Lamellar WS2 and Their Synergistic Effect with Anti-Wear Agent ZDDP

2019 ◽  
Vol 10 (1) ◽  
pp. 115 ◽  
Author(s):  
Na Wu ◽  
Ningning Hu ◽  
Jinhe Wu ◽  
Gongbo Zhou

The microscale/nanoscale lamellar-structure WS2 particles with sizes of 2 µm and 500 nm were synthesized by solid-phase reaction method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The synergies between microscale/nanoscale WS2 particles and ZDDP as lubricating oil additives was evaluated by means of UMT-2 tribometer at room temperature. The wear scars were examined with SEM and electron-probe micro-analyzer (EPMA). The results show that the anti-wear properties were improved and the friction coefficient was greatly decreased with the simultaneous addition of WS2 particles and ZDDP, and the largest reduction of friction coefficient was 47.2% compared with that in base oil. Moreover, the presence of ZDDP additive in the lubricant further enhances the friction-reduction and anti-wear effect of microscale/nanoscale WS2. This confirms that there is a synergistic effect between WS2 particles and ZDDP.

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Flavio A. C. Vidal ◽  
Antonio F. Ávila

A top-down approach is employed to investigate the tribological effect of adding nanographite platelets (NGPs) to mineral base oil (MBO). The performance of the NGP-modified MBO was evaluated by examining the friction and anti-wear properties. Four different types of NGPs produced by two different processes were employed. The optimal NGP-modified MBO attained a significant wear and friction reduction when compared with the MBO without NGPs. The process used to exfoliate the graphite nanoplatelet samples provided better wear properties because of the graphene layers' smoother sliding mechanism. Graphene layers seeped inside the groove marks to keep the friction coefficient low.


2007 ◽  
Vol 353-358 ◽  
pp. 2139-2142
Author(s):  
Chang Sheng Li ◽  
Yan Qing Liu ◽  
Jun Mao Li

large-scale and elegant one-dimension tubular nanostructure TaS2, have been generated successfully employing solid-phase reaction growth with tantalum and sulfur powders. Detailed experimental procedures, and the characterization of associated product, have been evaluated using transmission electron microscopy (TEM) and other techniques. The results show that the reaction yielded a lot of one dimension nanostructures of TaS2 with average diameter of one hundred nanometers and length of several micrometers (or several ten micrometers). Moreover, effect of TaS2 nanostructure, as additive in commercial lubricating oil T40, was initially measured by UMT Multi-specimen Test System (UMT-2). The results show, as additive, antiwear and bearing weight ability of 1-D TaS2 nanostructure, excelled ordinary lubricating oil at atmosphere.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Hengli Xiang ◽  
Genkuan Ren ◽  
Yanjun Zhong ◽  
Dehua Xu ◽  
Zhiye Zhang ◽  
...  

Fe3O4@C nanoparticles were prepared by an in situ, solid-phase reaction, without any precursor, using FeSO4, FeS2, and PVP K30 as raw materials. The nanoparticles were utilized to decolorize high concentrations methylene blue (MB). The results indicated that the maximum adsorption capacity of the Fe3O4@C nanoparticles was 18.52 mg/g, and that the adsorption process was exothermic. Additionally, by employing H2O2 as the initiator of a Fenton-like reaction, the removal efficiency of 100 mg/L MB reached ~99% with Fe3O4@C nanoparticles, while that of MB was only ~34% using pure Fe3O4 nanoparticles. The mechanism of H2O2 activated on the Fe3O4@C nanoparticles and the possible degradation pathways of MB are discussed. The Fe3O4@C nanoparticles retained high catalytic activity after five usage cycles. This work describes a facile method for producing Fe3O4@C nanoparticles with excellent catalytic reactivity, and therefore, represents a promising approach for the industrial production of Fe3O4@C nanoparticles for the treatment of high concentrations of dyes in wastewater.


2016 ◽  
Vol 697 ◽  
pp. 510-514 ◽  
Author(s):  
Feng Rui Zhai ◽  
Ke Shan ◽  
Ruo Meng Xu ◽  
Min Lu ◽  
Zhong Zhou Yi ◽  
...  

In the present paper, the ZrB2/h-BN multiphase ceramics were fabricated by SPS (spark plasma sintering) technology at lower sintering temperature using h-BN, ZrO2, AlN and Si as raw materials and B2O3 as a sintering aid. The phase constitution and microstructure of specimens were analyzed by XRD and SEM. Moreover, the effects of different sintering pressures on the densification, microstructure and mechanical properties of ZrB2/h-BN multiphase ceramics were also systematically investigated. The results show that the ZrB2 was obtained through solid phase reaction at different sintering pressures, and increasing sintering pressure could accelerate the formation of ZrB2 phase. As the sintering pressure increasing, the fracture strength and toughness of the sintered samples had a similar increasing tendency as the relative density. The better comprehensive properties were obtained at given sintering pressure of 50MPa, and the relative density, fracture strength and toughness reached about 93.4%, 321MPa and 3.3MPa·m1/2, respectively. The SEM analysis shows that the h-BN grains were fine and uniform, and the effect of sintering pressure on grain size was inconspicuous. The distribution of grain is random cross array, and the fracture texture was more obvious with the increase of sintering pressure. The fracture mode of sintered samples remained intergranular fracture mechanism as sintering pressure changed, and the grain refinement, grain pullout and crack deflection helped to increase the mechanical properties.


1980 ◽  
Vol 18 (3) ◽  
pp. 469-476 ◽  
Author(s):  
Ľ. Žúrková ◽  
K. Gáplovská ◽  
V. Suchá

2014 ◽  
Vol 215 ◽  
pp. 470-473 ◽  
Author(s):  
Tamara V. Drokina ◽  
German A. Petrakovskii ◽  
Dmitrii A. Velikanov ◽  
Maksim S. Molokeev

In this paper we are reported about a peculiarity of the crystal structure and the magnetic state of TmFeTi2O7. The compound TmFeTi2O7 has been synthesizedusing the solid-phase reaction method. Using X-ray diffraction method the disorder in the distribution of the iron ions over five nonequivalent crystal sites was observed, also the populations of the iron atoms positions were determined. We show that below Tf = 6 K the magnetization of TmFeTi2O7 depends on the magnetic history of the sample. There are indications for spin glass state. This results allow us to assume the state of spin glass is realized below freezing temperature Tf = 6 K in TmFeTi2O7.


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