Investigation of wear on the upper edges of webs of thin-film coated single-screw extruders processing pure polymers

2021 ◽  
Vol 63 (2) ◽  
pp. 143-150
Author(s):  
Torben Buttler ◽  
Jens Hamje ◽  
Rolf Reiter ◽  
Volker Wesling
Keyword(s):  
Wear Behavior ◽  
Cold Work ◽  
Polymer Processing ◽  
Chromium Nitride ◽  
Metallographic Examination ◽  
Test Speed ◽  
Single Screw Extruders ◽  
Pin On Disk ◽  
Screw Extruders ◽  
Disk Test

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.

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 ◽  
...  
Keyword(s):  
High Temperature ◽  
Friction Coefficient ◽  
Phase Formation ◽  
Wear Behavior ◽  
Stoichiometric Ratio ◽  
Excess Copper ◽  
High Temperature Synthesis ◽  
Oxide Particles ◽  
Pin On Disk ◽  
Disk Test

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.

Friction characteristics of hybrid magnesium alloy composites reinforced with carbon nanotube and cerium

2017 ◽  
Vol 69 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Fatma Nazli Sari ◽  
Mehmet Baki Karamis ◽  
Yahya Kaya
Keyword(s):  
Rare Earth ◽  
Carbon Nanotube ◽  
Wear Mechanism ◽  
Wear Behavior ◽  
Mg Alloy ◽  
Content Type ◽  
Test Configuration ◽  
Pin On Disk ◽  
Disk Test ◽  
Composite Samples

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.

Friction and Wear Performance of Epoxy Resin Reinforced With Boron Nitride Nanoplatelets

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Mürsel Ekrem ◽  
Hayrettin Düzcükoğlu ◽  
Muhammet Ali Şenyurt ◽  
Ömer Sinan Şahin ◽  
Ahmet Avcı
Keyword(s):  
Mechanical Properties ◽  
Heat Conduction ◽  
Boron Nitride ◽  
Epoxy Resin ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Wear Performance ◽  
Friction And Wear Behavior ◽  
Pin On Disk ◽  
Disk Test

In this study, the effects of addition of boron nitride nanoplatelets (BNNPs) upon friction and wear behavior of epoxy resin have been investigated by using pin-on-disk test. It has been reported in the literature that certain amounts of BNNP addition can be useful for enhancement of mechanical properties. Therefore, it is very important to obtain the effect of such addition upon friction and wear performance of epoxy resin. BNNPs have been incorporated at 0.3–0.5–0.7–1 wt %. It is shown that BNNP addition results in decrease in friction coefficient and wear. It is also shown that the best results are obtained with 0.5% nanoplatelet addition. It is also observed that heat conduction of epoxy resin is enhanced by the nanoplatelet addition.

Modelling of Mixing in Single Screw Extruders

2006 ◽  
Vol 514-516 ◽  
pp. 1409-1413
Author(s):  
Natália Domingues ◽  
António Gaspar-Cunha ◽  
José A. Covas
Keyword(s):  
Computer Modelling ◽  
Polymer Processing ◽  
Liquid System ◽  
Single Screw ◽  
Single Screw Extrusion ◽  
Single Screw Extruders ◽  
Processing Techniques ◽  
New Applications ◽  
Dispersive Mixing ◽  
Screw Extruders

Polymer extrusion is one of the most important polymer processing techniques. Modelling of the phenomena developing inside single screw extruders enabled the development of commercial software which can be used to study the performance of existing systems and to define the equipment characteristics for new applications. Although mixing is one of the most important performance measures of extrusion, it is usually disregarded in the available programs. Consequently, in this work mathematical models for quantifying mixing in single screw extruders are developed and subsequently inserted in a global computer modelling program of single screw extrusion. The mixing model quantifies distributive and dispersive mixing and coalescence mechanisms in a liquid-liquid system. This is accomplished by calculating the variation of the thickness of drops considered to be suspended in the polymeric matrix, taking into account the rate and drop break-up time and the coalescence probability. The influence of several parameters, such as viscosities, initial drop dimension, screw speed and barrel temperature, are examined

THE EFFECT OF ELECTROLYTE TEMPERATURE AND SEALING SOLUTION IN ANODIZING OPERATION ON HARDNESS AND WEAR BEHAVIOR OF 7075 -T6 ALUMINUM ALLOY

2019 ◽  
Vol 26 (02) ◽  
pp. 1850143
Author(s):  
SAEED NIYAZBAKHSH ◽  
KAMRAN AMINI ◽  
FARHAD GHARAVI
Keyword(s):  
Weight Loss ◽  
Wear Resistance ◽  
Aluminum Alloy ◽  
Wear Behavior ◽  
Anodic Oxide ◽  
Boiling Water ◽  
Electrolyte Temperature ◽  
Oxide Coatings ◽  
Sodium Dichromate ◽  
Pin On Disk

Anodic oxide coatings are applied on aluminum alloys in order to improve corrosion resistance and to increase hardness and wear resistance. In the current study, a hard anodic coating was applied on AA7075-T6 aluminum alloy. To survey the anodizing temperature (electrolyte temperature) effect, three temperatures, namely, [Formula: see text]C, 0∘C and 5∘C were chosen and the samples were sealed in boiling water and sodium dichromate to study the role of sealing. For measuring the oxide coatings porosity and hardness and also for comparing the samples’ wear resistance field-emission scanning electron microscopy (FESEM), microhardness test and pin-on-disk method were utilized, respectively. The results showed that by increasing the anodizing temperature, hardness and consequently wear resistance decreased so that hardness and weight loss in the samples with no sealing decreased from 460[Formula: see text]HV and 0.61[Formula: see text]mg at [Formula: see text]C to 405 and 358[Formula: see text]HV and 1.05 and 1.12[Formula: see text]mg at 0∘C and 5∘C, respectively, which is due to the porosity increment by increasing the anodizing temperature. Also, sealing in boiling water and dichromate contributed to soft phases and coating hydration, which resulted in a decrease in hardness and wear resistance. Hardness and weight loss in the coated samples at [Formula: see text]C decreased from 460[Formula: see text]HV and 0.61[Formula: see text]mg in the samples with no sealing to 435 and 417[Formula: see text]HV and 0.72 and 0.83[Formula: see text]mg in the samples sealed in boiling water and dichromate, respectively.

Sliding Wear Behavior of Remelted Al2O3-TiO2 Plasma Sprayed Coatings on Titanium

2016 ◽  
Vol 254 ◽  
pp. 231-236 ◽  
Author(s):  
Ion Dragoş Uţu ◽  
Gabriela Marginean ◽  
Iosif Hulka ◽  
Viorel Aurel Şerban
Keyword(s):  
Sliding Wear ◽  
Wear Behavior ◽  
Pure Titanium ◽  
Titanium Substrate ◽  
Atmospheric Plasma ◽  
Wear Properties ◽  
Before And After ◽  
Sprayed Coating ◽  
Pin On Disk ◽  
Sprayed Coatings

Microstructure and wear properties of the Al2O3-13.wt% TiO2 thermally sprayed coatings before and after remelting were investigated in this study. The coatings were deposited on a pure titanium substrate using the atmospheric plasma spraying (APS) process. The as-sprayed coatings were electron beam (EB) modified in order to improve their compactness and bonding strength.The effect of EB remelting on the microstructure, phase constituents and wear properties was investigated using scanning electron microscopy (SEM), X-Ray diffraction technique and hardness measurements. The sliding wear behavior was tested using a pin on disk method.The results showed that the remelting process had a positive effect removing the lamellar defect of the as-sprayed coating and improving the compactness, hardness and wear behavior.

Effect of Phase Transformation on the Wear Behavior of NiTi Alloy

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
M. Abedini ◽  
H. M. Ghasemi ◽  
M. Nili Ahmadabadi ◽  
R. Mahmudi
Keyword(s):  
Wear Behavior ◽  
Niti Alloy ◽  
Testing Temperature ◽  
Compression Tests ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Mechanical And Tribological Properties ◽  
Ni Alloy ◽  
Shape Memory Effects ◽  
Pin On Disk

In this paper, mechanical and tribological properties of a Ti-50.3 at % Ni alloy were investigated. The transformation temperatures of the alloy were determined using differential scanning calorimetry. Three-point bending tests were performed to characterize the pseudoelasticity and shape memory effects. Uni-axial compression tests were also performed at different testing temperatures. The wear tests were conducted using a pin-on-disk tribometer at testing temperatures ranging from 0°C to 80°C. The wear results showed that with increasing the testing temperature from 0°C to 50°C, the wear of the alloy was decreased, which could be attributed to the higher pseudoelasticity of the alloy at a testing temperature of 50°C. The pseudoelasticity of the alloy decreased at a higher testing temperature of 80°C; however, its wear resistance increased considerably due to higher ultimate strength and work hardening.

Sign in / Sign up

Export Citation Format

Share Document