scholarly journals Wear behavior of self-propagating high-temperature synthesized Cu-TiO2 nanocomposites

2021 ◽  
Vol 1 (3) ◽  
pp. 127-134
Author(s):  
Hossein Aghajani ◽  
Mohammad Roostaei ◽  
Shaya Sharif Javaherian ◽  
Arvin Taghizadeh Tabrizi ◽  
Ali Abdoli Silabi ◽  
...  

In this paper, the copper-based nanocomposites with TiO2 nanoparticles were synthesized by the self-propagating high-temperature synthesis (SHS) process. The effect of the different amounts of excess copper, in comparison with the stoichiometric ratio (CuO:Ti ratios of 1:1, 2:1, and 3:1), on the phase formation of achieved samples was studied. A thermodynamical study showed that increasing the excess copper powder reduces the adiabatic temperature, which helps the phase formation. The maximum Brinell hardness (89) was obtained for the sample with the CuO:Ti ratio of 1:1. Finally, the wear behavior of the synthesized nanocomposites was evaluated by the pin on disk test, and the variation of friction coefficient and lost weight were measured. The friction coefficient decreased by the formation of phases and distribution of titanium oxide particles during the SHS process in the presence of the stoichiometric ratio of CuO:Ti. Therefore, the wear behavior was improved. The lowest depth of wear trace was measured 0.68 where the ratio of CuO: Ti was 1:1.

Author(s):  
Sahar Ghatrehsamani ◽  
Saleh Akbarzadeh

Wear coefficient and friction coefficient are two of the key parameters in the performance of any tribo-system. The main purpose of the present research is to use continuum damage mechanics to predict wear coefficient. Thus, a contact model is utilized that can be used to obtain the friction coefficient between the contacting surfaces. By applying this model to the continuum damage mechanics model, the wear coefficient between dry surfaces is predicted. One of the advantages of using this model is that the wear coefficient can be numerically predicted unlike other methods which highly rely on experimental data. In order to verify the results predicted by this model, tests were performed using pin-on-disk test rig for several ST37 samples. The results indicated that the wear coefficient increases with increasing the friction coefficient.


2021 ◽  
Vol 63 (2) ◽  
pp. 143-150
Author(s):  
Torben Buttler ◽  
Jens Hamje ◽  
Rolf Reiter ◽  
Volker Wesling

Abstract During polymer extrusion there are a variety of situations in which the screwthread of the extrusion screw has an unlubricated metal-to-metal contact with the barrel wall. At the same time the screw coating is subjected to the highest loads. The combination of a secondary hardening cold work steel 1.2379 and a chromium nitride coating deposited by ARC-PVD, which is frequently used in polymer processing, is characterized and investigated. The characterization is done by metallographic examination, SEM and CLSM. The tests were performed on a pin-on-disk and a pin-roll test rig. Different roughness levels were tested on the pin-on-disk test, where massive differences in wear behavior were found. A hybrid surface structure is proposed to optimize the tribosystem. On the pin-on-disk test stand, rollers made of the same material pairing were tested. The test speed was varied to highlight differences and similarities between the tribological systems. A wear minimization of 50 % was achieved and the similarities between the tribological systems were highlighted. In addition, the investigations led to the development of a new model thesis which provides a reason for the development of stippling on the screw when processing polycarbonate.


2012 ◽  
Vol 157-158 ◽  
pp. 1628-1631
Author(s):  
Xiao Dong Yang ◽  
Zhuo Juan Yang ◽  
You Quan Chen

By using pin-on-disk wear test method, the wear behavior of W9Gr4V high speed steel with smooth and non-smooth concave samples which treated by laser texturing technology was investigated between room temperature and 500 . It was found that the anti-wear ability of the non-smooth concave samples was increased more than that of the smooth ones and the anti-wear ability of the non-smooth samples was evident than the smooth ones at temperature increasing. In this paper, the anti-wear mechanism of non-smooth concave samples and wear characteristics with smooth and non-smooth samples in high-temperature were analyzed.


2010 ◽  
Vol 658 ◽  
pp. 408-411
Author(s):  
Hui Xie ◽  
Lei Jia ◽  
Si Ming Wang ◽  
Ji Ling Zhu ◽  
Zhen Lin Lu

Cu-Mo-Si alloys with different Cu contents were prepared by self-propagation high-temperature synthesis (SHS). The microstructure and the worn surface morphology were observed using scanning electron microscopy (SEM) together with energy dispersive X-ray spectroscopy (EDS) analysis. Phase composition was determined by X-ray diffraction (XRD). The wear behavior of the Cu-Mo-Si alloys was characterized by pin-on-disc wear tester. The results showed that most of Si atoms dissolved in Cu matrix or resulted in formation of compound with Cu, while only small amount of Si atoms reacted with Mo atoms to form Mo5Si3 particles in the Cu-Ni-Si alloys with 80% Cu content. The wear rate of Cu-Mo-Si alloys descended with a decrease of Cu content, and the predominant wear mechanism could be identified as abrasive wear for Cu content less than 90% and plastic deformation for Cu content higher than 90%.


2018 ◽  
Vol 913 ◽  
pp. 168-175
Author(s):  
Xian Ye Liang ◽  
Guang Bao Mi ◽  
Liang Ju He ◽  
Pei Jie Li

The abnormal local friction and wear phenomena usually generate during the service of the titanium alloy rotor /stator parts of the aero engine compressor under high temperature conditions. This phenomenon is the main cause of the occurrence of titanium fire failure and has great harm. In the present investigation the friction and wear behavior of the combustion resistant titanium alloy at high temperature was studied by finite element numerical simulation and experimental verification of the pin-on-disk model. Firstly, the geometrical model of the round bottom pin-on-disk contact was established. Then, the friction process was simulated by the Coulomb friction model. The ALE technique of ABAQUS was applied to move the contact nodes and update the grid. The finite element simulation of the ARCHARD wear model was realized. In order to deal with the increasing contact area, a simplify wear direction was proposed. Finally, the wear depth and volume was calculated and the wear law at 500 °C -900 °C was revealed. The results show that the wear process is gentle at the temperature of 500-700 °C, and the wear depth is within 0.08mm when the sliding distance reaches 1800m. When the temperature exceeds 800 °C, the wear rate increased sharply and the wear depth beyond 0.1mm, the FE result is consistent with the test results.


2017 ◽  
Vol 69 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Fatma Nazli Sari ◽  
Mehmet Baki Karamis ◽  
Yahya Kaya

Purpose The paper aims to clarify the hybrid Mg alloy composites reinforced with multi-walled carbon nanotube (MWCNT) and Cerium (Ce) rare earth element tribological properties were investigated by using pin-on-disk test configuration under dry and lubricated sliding conditions. Design/methodology/approach The paper opted for an experimental study with composite samples under lubricated conditions. Their tribological properties were investigated by using pin-on-disk test configuration under dry and lubricated sliding conditions. Wear tests were carried out at 20°C temperature. Wear behavior of Mg alloy composites was evaluated as maximum coefficient of friction and the variation of the maximum frictional forces of the samples. Findings The reinforcements such as Ce and MWCNT have a decreasing effect between 100 and 200 rpm speed tests for friction coefficient and friction force of Mg alloy. The microstructure has an important effect on the wear mechanism. There can be both adhesive and abrasive wear mechanism for the same composite at different sliding speeds. It is determined that there is no systematic relationship between reinforcement percent and sliding speed related to wear behavior of AZ 41 matrix composites reinforced with CNT and Ce. The results indicate that different wear mechanisms occur at different sliding speeds. The sliding speed has effect on both an increment and decrement for wear. Research limitations/implications Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the different reinforced composite samples further. Practical implications The paper includes implications for the development of a hybrid composite reinforced with rare earth elements and MWCNT. Originality/value This paper fulfils an identified need to study a hybrid composite reinforced with rare earth elements and MWCNT.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Shojiro Miyake ◽  
Takanori Shindo ◽  
Masatoshi Miyake

Diamond-like carbon (DLC) films are deposited by bend filtered cathodic vacuum arc (FCVA) technique with DC and pulsed bias voltage. The effects of varying bias voltage on nanoindentation and nanowear properties were evaluated by atomic force microscopy. DLC films deposited with DC bias voltage of −50 V exhibited the greatest hardness at approximately 50 GPa, a low modulus of dissipation, low elastic modulus to nanoindentation hardness ratio, and high nanowear resistance. Nanoindentation hardness was positively correlated with the Raman peak ratioId/Ig, whereas wear depth was negatively correlated with this ratio. These nanotribological properties highly depend on the films’ nanostructures. The tribological properties of the FCVA-DLC films were also investigated using a ball-on-disk test. The average friction coefficient of DLC films deposited with DC bias voltage was lower than that of DLC films deposited with pulse bias voltage. The friction coefficient calculated from the ball-on-disk test was correlated with the nanoindentation hardness in dry conditions. However, under boundary lubrication conditions, the friction coefficient and specific wear rate had little correlation with nanoindentation hardness, and wear behavior seemed to be influenced by other factors such as adhesion strength between the film and substrate.


1998 ◽  
Vol 13 (9) ◽  
pp. 2610-2613 ◽  
Author(s):  
Kexin Chen ◽  
Changchun Ge ◽  
Jiangtao Li

The self-propagating high temperature synthesis (SHS) of Al–Zr–N system composite ceramics was investigated in this paper. The melting point of Al was low (Tm = 660 °C), while that of Zr was high (Tm =1855 °C). Therefore, Al will melt and coalesce during reaction, which inhibit diffusion of nitrogen from outside the metal compact to interior due to collapse of the pore openings, while Zr will not melt under the combustion temperature which is lower than its melting point. It will not affect the permeation of nitrogen under the conditions. Accordingly, the ratio of Al and Zr in the initial mixed powders will affect the permeation of nitrogen from outside the sample to the interior, which results in different phase formation of the products. In this study, the relationship between the combustion parameters and the phase formation of the products will be experimentally determined through XRD analysis, and then thermodynamically analyzed.


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