scholarly journals Dry Sliding Behavior of an Aluminum Alloy after Innovative Hard Anodizing Treatments

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3281
Author(s):  
Chiara Soffritti ◽  
Annalisa Fortini ◽  
Anna Nastruzzi ◽  
Ramona Sola ◽  
Mattia Merlin ◽  
...  

This work evaluates the dry sliding behavior of anodic aluminum oxides (AAO) formed during one traditional hard anodizing treatment (HA) and two golden hard anodizing treatments (named G and GP, respectively) on a EN AW-6060 aluminum alloy. Three different thicknesses of AAO layers were selected: 25, 50, and 100 μm. Prior to wear tests, microstructure and mechanical properties were determined by scanning electron microscopy (VPSEM/EDS), X-ray diffractometry, diffuse reflectance infrared Fourier transform (DRIFT-FTIR) spectroscopy, roughness, microhardness, and scratch tests. Wear tests were carried out by a pin-on-disc tribometer using a steel disc as the counterpart material. The friction coefficient was provided by the equipment. Anodized pins were weighed before and after tests to assess the wear rate. Worn surfaces were analyzed by VPSEM/EDS and DRITF-FTIR. Based on the results, the GP-treated surfaces with a thickness of 50 μm exhibit the lowest friction coefficients and wear rates. In any case, a tribofilm is observed on the wear tracks. During sliding, its detachment leads to delamination of the underlying anodic aluminum oxides and to abrasion of the aluminum substrate. Finally, the best tribological performance of G- and GP-treated surfaces may be related to the existence of a thin Ag-rich film at the coating/aluminum substrate interfaces.

2015 ◽  
Vol 830-831 ◽  
pp. 333-336 ◽  
Author(s):  
M. Ananda Jothi ◽  
S. Ramanathan

Titanium and its alloys exhibit a unique combination of physical and corrosion resistance properties which make them ideal materials for space flight engine component such as disks and blades of compressor, marine applications, chemical industries and many bio medical applications. However the use of these materials is limited due to its poor tribological properties. Dry sliding wear tests were performed on Ti-6Al-4V using a pin-on-disc (EN31 steel) configuration. Wear rates were measured with different load and sliding velocity at a constant sliding distance. Microstructures of worn surfaces were characterized by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).


2007 ◽  
Vol 353-358 ◽  
pp. 898-901 ◽  
Author(s):  
Xue Tong Sun ◽  
Cheng Xin Lin

In the present work, the wear behaviour of coatings produced on Ti-6Al-4V alloy by micro-arc oxidation method was studied. The wear tests were performed using a pin-on-disc wear machine under dry sliding conditions. It is found that the MAO coating can efficiently improve the wear-resistant performance of Ti alloy in the test range of this paper. The coated samples demonstrated wear rates up to 5-12 times lower than that of the uncoated substrates tested. The wear behaviours are deeply characterized by the variations of coating structure and composition.


2015 ◽  
Vol 67 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Akin Akinci

Purpose – The purpose of this paper is to investigate the friction and wear performance of pure polycarbonate (PC) and 5-30 per cent wollastonite-filled (by weight) PC were comparatively evaluated under dry sliding conditions. Wear tests were carried out at room temperature under the loads of 5-20 N and at the sliding speeds of 0.5-1.5 m/s. Design/methodology/approach – The microstructures of the wollastonite, pure PC and composites were examined by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis. The friction and wear tests were realized using a pin-on-disk arrangement against the hardened AISI 4140 steel. Findings – The result of this study indicated that the coefficients of friction wear rate of the materials were significantly influenced by an increase in wollastonite content. The friction coefficient of the PC was getting decreased from 0.457 to 0.198 with an increase in wollastonite content, depending on applied loads and sliding speeds. On the other hand, the results showed that the wear rates of pure PC and wollastonite-filled PCs decreased with an increase in loads. The wear rate of the PC decreased from 1.2 × 10−6 to 8.7 × 10−6 mm3/m with an increase in wollastonite content, depending on applied loads. Originality/value – There are many reports which deal with the friction and wear performance of the polymers and polymer composites. However, the effect of wollastonite effect on tribological performance of PC has up to now not been extensively researched.


2012 ◽  
Vol 507 ◽  
pp. 191-195 ◽  
Author(s):  
Pavol Hvizdoš ◽  
Viktor Puchý ◽  
Daniel Drdlík ◽  
Jaroslav Cihlář

Alumina and both tetragonal and cubic zirconia based composites with various volume fractions of constituents as well as with addition of carbon nanofibers were prepared by EPD. Mechanical properties (hardness, Youngs modulus) were measured by depth sensing indentation methods and related to chemical composition. Tribological behavior was studied using pin-on-disc technique at room temperatures in air at dry sliding. Coefficient of friction and wear rates were measured, the types of wear regimes were observed and damage micromechanisms identified.


Author(s):  
C.Y.H. Lim ◽  
L. Lu

This paper explores the wear characteristics of nanocrystalline Mg-5%Al-5%Nd, synthesized by mechanical alloying. Pin-on-disc unlubricated sliding wear tests were conducted against a hardened tool-steel counterface under loads of 10 and 30 N, and within a velocity range of 0.2-5.0 m/s. Despite its appreciably superior mechanical properties, the nanostructured alloy did not exhibit the expected improvement in wear resistance when compared to its conventional microngrain- sized counterpart; in fact, the former performed worse when testing conditions became more severe. Scanning electron microscopy (SEM) suggested that extensive delamination in the nanocrystalline alloy was the primary reason for its high wear rates. This wear mechanism was promoted by the presence of MgxNd dispersiods, which were found only within the nanocrystalline material. These compounds likely resulted from the long duration (20 hrs) of ball-milling, which was the mechanical alloying technique employed to reduce the grain size of the final alloy.


2012 ◽  
Vol 184-185 ◽  
pp. 1006-1009
Author(s):  
San Ming Du ◽  
Yue Chen ◽  
Yong Zhen Zhang

In the present study, amorphous coatings on plain steel substrate were prepared by electric arc spraying technique. The high-speed dry sliding tribological properties of the coating were investigated on a pin-on-disc tribo-meter. The results show that amorphous phase generates in the sprayed coating. When the sliding speeds are less than 40m/s, the friction coefficient increases. The friction coefficients decrease with the sliding speed exceeding 60m/s. The wear rates increase with increasing the sliding. Phase transition occurs in the friction process.


Author(s):  
Songbo Xu ◽  
Aydar Akchurin ◽  
Tian Liu ◽  
Weston Wood ◽  
X. W. Tangpong ◽  
...  

High density polyethylene (HDPE) is widely used as a bearing material in industrial application because of its low friction and high wear resistance properties. Carbon nanofiber (CNF) reinforced HDPE nanocomposites are promising materials for biomedical applications as well, such as being the bearing materials in total joint replacements. The main objective of the present study is to investigate how the wear of HDPE can be altered by the addition of either pristine or silane treated CNFs at different loading levels (0.5 wt. % and 3 wt. %). Two types of silane coating thicknesses, 2.8 nm and 46 nm, were applied on the surfaces of oxidized CNFs to improve the interfacial bonding strength between the CNFs and the matrix. The CNF/HDPE nanocomposites were prepared through melt mixing and hot-pressing. The coefficients of friction (COFs) and wear rates of the neat HDPE and CNF/HDPE nanocomposites were determined using a pin-on-disc tribometer under dry sliding conditions. The microstructures of the worn surfaces of the nanocomposites were characterized using both scanning electron microscope (SEM) and optical microscope to analyze their wear mechanisms. Compared with the neat HDPE, the COF of the nanocomposites were reduced. The nanocomposite reinforced with CNFs coated with the thicker silane coating (46 nm) at 0.5 wt. % loading level was found to yield the highest wear resistance with a wear rate reduction of nearly 68% compared to the neat HDPE.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Volker Franco Steier ◽  
Edgar Sobral Ashiuchi ◽  
Lutz Reißig ◽  
José Alexander Araújo

The aim of this work is to evaluate the effect of a deep cryogenic treatment (DCT) on the wear behavior and on the microstructure of an aluminum alloy. In order to compare the level of improvement on the wear resistance provided by the DCT with a more traditional technique, a test matrix which included DCT, CrN coated specimens, and combinations of both modification methods was conducted. The wear behavior was investigated using microabrasive wear tests. The cryogenic treated specimens proved to have similar low wear rates as the specimens coated with CrN. The most distinct improvement was reached with a combination of both techniques. In the case of the DCT, the performed microstructural analysis identified the generation of additional GP-zones as the reason for the improved wear resistance.


2020 ◽  
Vol 12 (7) ◽  
pp. 1034-1045
Author(s):  
Essam R. I. Mahmoud ◽  
Ali Algahtani ◽  
Sohaib Z. Khan ◽  
Gulam Mohammed Sayeed Ahmed

Aluminum alloys have attractions to be used for a wide range of applications. Although the passive film on aluminum can provide corrosion protection, it has limited wear resistance in oil and gas applications due to the aggressive environment. This work has investigated the enhancements of hard anodizing on the performance of 6082-T6 aluminum alloy surface against erosion and corrosion test environments. The study investigates the surface roughness and hardness of the hard-anodized coating before going deeper in the cross-section to study in details the macro/microstructure of the formed layer. The erosion resistance of the coated layer, in particular, the effect of sand concentration and temperature variations to the aqueous slurry impingement against material properties such as adhesion, ductility, and roughness were investigated. In addition, a series of electrochemistry tests have been conducted to verify the corrosion performance. As a reference, the un-coated aluminum substrate was instigated in all the experiments. The resulted hard anodized coating layer had good adhesion with the aluminum substrate and was consisted of two distinct amorphous sub-layers of almost 50 m thick with some elongated porosity. It has been shown that the erosion resistance of aluminum alloy can be highly improved by hard anodizing, especially at high temperature. The hard-anodized sample shows almost twice hardness values compared with aluminum substrate for both eroded and un-eroded conditions. For the corrosion behavior, the hard-anodizing coating has lower corrosion current density than the aluminum substrate.


Author(s):  
A. H. S. Jones ◽  
D Camino ◽  
D. G. Teer ◽  
J Jiang

A series of new diamond-like carbon (DLC) coatings has been produced by magnetron sputtering using in-house equipment. The new hydrogen-free pure carbon coatings were deposited by sputtering carbon targets in a pure argon atmosphere. With a metallic interlayer, they have shown improved tribological properties when compared with conventional hydrogenated DLC in pin-on-disc and reciprocating wear tests. The films have also shown the ability to perform in oil, water and dry environments, and to protect the counterpart. The method of ball cratering on wear tracks provided taper sections to allow the analysis of coating wear, interface condition and failure mechanisms. Wear rates as low as 3 × 10−17 m3/N m are shown for 100 N, 10000 cycle reciprocating wear tests in air and in water. Scratch tests have been used to assess coating adhesion with critical loads as high as 70 N. Results from nano-indentation, Raman spectroscopy, electron energy loss spectroscopy and X-ray diffraction are also reported.


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