scholarly journals Wear behaviour of duplex (PN+PVD) treated layers produced on X42CR13 steel

2019 ◽  
Vol 9 (1) ◽  
pp. 3-11
Author(s):  
Shiraz Ahmed Siddiqui ◽  
Marosné Berkes Mária

Wear, corrosion and fatigue are among the most important mechanisms that lead to surface damage, which, ultimately, leads to failure of the components. There is an increasing demand for reducing failures and the related costs due to wear and surface shortcomings of heavily loaded engineering components. Thus, application of surface technologies gives a great potential for saving resources and providing improved technology. The presented research work involves characterization of a duplex treated i.e. plasma nitrided (at two different temperatures 520 °C, 550 °C) and PVD coated – X42Cr13/W plastic mould tool steel with special emphasis on the ball-on-disc wear behaviour of tested specimens. The objective is to study and evaluate the effect of different nitriding treatments prior to coating on the wear behaviour of specimens having different surface preparations. Also, it has been established that duplex treatment (plasma nitriding + physical vapour deposition [PVD] coating) gives better and improved properties as compared to individual treatments.

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3588
Author(s):  
Brigita Polanec ◽  
Franc Zupanič ◽  
Tonica Bončina ◽  
Frančišek Tašner ◽  
Srečko Glodež

A comprehensive experimental investigation of the wear behaviour of coated spur polymer gears made of POM is performed in this study. The three physical vapour deposition (PVD) coatings investigated were aluminium (Al), chromium (Cr), and chromium nitrite (CrN). Al was deposited in three process steps: By plasma activation, metallisation of Al by the magnetron sputtering process, and by plasma polymerisation. Cr deposition was performed in only one step, namely, the metallization of Cr by the magnetron sputtering process. The deposition of CrN was carried out in two steps: the first involved the metallization of Cr by the magnetron sputtering process while the second step, vapour deposition, involved the reactive metallisation of Cr with nitrogen, also by the magnetron sputtering process. The gears were tested on an in-house developed testing rig for different torques (16, 20, 24 and 30 Nm) and rotational speed of 1000 rpm. The duration of the experiments was set to 13 h, when the tooth thickness, and, consequently, the wear of the tooth flank was recorded. The experimental results showed that the influence of metallisation with aluminium, chromium, and chromium nitrite surface coatings on the wear behaviour of the analysed polymer gear is not significant. This is probably due to the fact that the analysed coatings were, in all cases, very thin (less than 500 nm), and therefore did not influence the wear resistance significantly. In that respect, an additional testing using thicker coatings should be applied in the further research work.


Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).


2013 ◽  
Vol 770 ◽  
pp. 68-71 ◽  
Author(s):  
Supphadate Sujinnapram ◽  
Uraiphorn Termsuk ◽  
Atcharawan Charoentam ◽  
Sutthipoj Sutthana

The nanocrystalline ZnO powders were synthesized by a direct thermal decomposition using zinc nitrate hexahydrate as starting materials. The precursor was characterized by TG-DTA to determine the thermal decomposition and crystallization temperature which was found to be at 325 oC. The precursors were calcined at different temperatures of 400, 500, and 600°C for 4 h. The structure of the prepared samples was studied by XRD, confirming the formation of wurtzite structure. The synthesized powders exhibited the UV absorption below 400 nm (3.10 eV) with a well defined absorption peak at around 285 nm (4.35 eV). The estimated direct bandgaps were obtained to be 3.19, 3.16, and 3.14 eV for the ZnO samples thermally decomposed at 400, 500, and 600°C, respectively.


Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 317
Author(s):  
Chithambaramani Ramalingam ◽  
Prakash Mohan

The increasing demand for cloud computing has shifted business toward a huge demand for cloud services, which offer platform, software, and infrastructure for the day-to-day use of cloud consumers. Numerous new cloud service providers have been introduced to the market with unique features that assist service developers collaborate and migrate services among multiple cloud service providers to address the varying requirements of cloud consumers. Many interfaces and proprietary application programming interfaces (API) are available for migration and collaboration services among cloud providers, but lack standardization efforts. The target of the research work was to summarize the issues involved in semantic cloud portability and interoperability in the multi-cloud environment and define the standardization effort imminently needed for migrating and collaborating services in the multi-cloud environment.


2020 ◽  
pp. 004051752092551
Author(s):  
Javeed A Awan ◽  
Saif Ur Rehman ◽  
Muhammad Kashif Bangash ◽  
Fiaz Hussain ◽  
Jean-Noël Jaubert

Curcumin is a naturally occurring hydrophobic polyphenol compound. It exhibits a wide range of biological activities such as antibacterial, anti-inflammatory, anti-carcinogenic, antifungal, anti-HIV, and antimicrobial activity. In this research work, antimicrobial curcumin nanofibrous membranes are produce by an electrospinning technique using the Eudragit RS 100 (C19H34ClNO6) polymer solution enriched with curcumin. The morphology and chemistry of the membrane are analyzed using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Kirby Bauer disk diffusion tests are carried out to examine the antibacterial effectiveness of the membrane. Experimental results show that the nanofibers produced are of uniform thickness morphology and curcumin is successfully incorporated into the nanofibrous mat, while no chemical bonding was observed between curcumin and the polymer. The antimicrobial curcumin nanofibrous membranes can be effectively applied as antimicrobial barrier in a wide variety of medical applications such as wound healing, scaffolds, and tissue engineering.


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1940 ◽  
Author(s):  
Levente Ferenc Tóth ◽  
Patrick De Baets ◽  
Gábor Szebényi

In this research work, unfilled and mono-filled polytetrafluoroethylene (PTFE) materials were developed and characterised by physical, thermal, viscoelastic, mechanical, and wear analysis. The applied fillers were graphene, alumina (Al2O3), boehmite alumina (BA80), and hydrotalcite (MG70) in 0.25/1/4/8 and 16 wt % filler content. All samples were produced by room temperature pressing–free sintering method. All of the fillers were blended with PTFE by intensive dry mechanical stirring; the efficiency of the blending was analysed by Energy-dispersive X-ray spectroscopy (EDS) method. Compared to neat PTFE, graphene in 4/8/16 wt % improved the thermal conductivity by ~29%/~84%/~157%, respectively. All fillers increased the storage, shear and tensile modulus and decreased the ductility. PTFE with 4 wt % Al2O3 content reached the lowest wear rate; the reduction was more than two orders of magnitude compared to the neat PTFE.


Wear ◽  
2005 ◽  
Vol 259 (7-12) ◽  
pp. 1097-1108 ◽  
Author(s):  
C. Boher ◽  
D. Attaf ◽  
L. Penazzi ◽  
C. Levaillant

1983 ◽  
Vol 27 ◽  
Author(s):  
R. Martinella ◽  
G. Chevallard ◽  
C. Tosello

ABSTRACTMechanically polished Ti6Al4V samples were implanted with 100 key nitrogen ions to a fluence of 5.1017 ions/cm2 at two different bulk tenneratures: 370°C and 470°C. Wear tests were carried out with a reciprocating slidina tribotester. Structural modifications and wear morphologies were studied by TEM and SEM. 370°C implanted sample showed the same wear behavior as unimplanted ones, while 470°C implanted sample showed better wear resistance because of a TiN hardened layer. Correlations- between microstructural modifications, wear behavior and mechanisms are reported: results agree with the delamination theory. Comparison with ion- and gas-nitrided samples are presented.


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