Abrasion Testing Machine Research Articles

The Effects of Copper and Polytetrafluoroethylene (PTFE) on Thermal Conductivity and Tribological Behavior of Polyoxymethylene (POM) Composites

The effects of copper and polytetrafluoroethylene (PTFE) on thermal conductivity and tribological behavior of polyoxymethylene (POM) composites were investigated by a hot disk thermal analyzer and an M-2000 friction and abrasion testing machine. The results indicated that the incorporation of 3 wt% copper particles into POM had little effect on the thermal conductivity of POM composites, but led to the decreased friction coefficient and wear rate of composites. As the copper content was increased, the thermal conductivity increased and reached 0.477 W m−1 K−1 for POM-25% Cu composite, an increase of 35.9% compared with that of unfilled POM, while the friction coefficient and wear rate of composites also increased. The incorporation of PTFE into POM-Cu composites had a negligible effect on the thermal conductivity of composites, but helped in the formation of a continuous and uniform transfer film and resulted in the reduction in the friction coefficient and wear rate of composites. The POM-15% Cu-10% PTFE composite, with a value of wear rate similar to unfilled POM possessed higher thermal conductivity and lower friction coefficient.

Effect of perfluoroalkylmethacrylate ester‐grafted‐linear low‐density polyethylene on the tribological property of polyoxymethylene–linear low‐density polyethylene composites

AbstractIn this work, perfluoroalkylmethacrylate ester (PFAMAE)‐grafted‐linear low‐density polyethylene (LLDPE) was synthesized by UV‐induced surface graft polymerization. The effect of PFAMAE‐grafted‐LLDPE on the tribological behavior of LLDPE‐filled polyoxymethylene (POM) composite was investigated using a friction and abrasion testing machine. The results showed that LLDPE‐g‐PFAMAE was a more effective modifier in improving tribological property of LLDPE‐filled POM composite than conventional maleic anhydride‐grafted‐polyethylene (PE‐g‐MAH). POM/LLDPE composite possessed much lower friction coefficient but higher wear rate than pristine POM. The incorporation of LLDPE‐g‐PFAMAE into POM/LLDPE further decreased the friction coefficient, which was 45% lower than that of POM. The wear rate of POM/LLDPE/LLDPE‐g‐PFAMAE composite was also reduced and was lower than that of pristine POM. The primary wear mechanisms of POM/LLDPE composite with and without LLDPE‐g‐PFAMAE were adhesive and abrasive wear. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

해양용 로프의 내마모성에 관한 연구

The laboratory inspection and analysis of several types of ropes such as edge tensile test, D/d tensile test and abrasion test were carried out in order to investigate the abrasion degradation by external damage and to obtain the fundamental data for measurement against the abrasion. PET ropes were socketed and evaluated under tensile testing. A yarn-on-yarn abrasion test machine has been developed to study the damage and failure associated with rubbing between fiber surfaces. The abrasion test method consists of sliding a length of interwrapped yarn against itself in a reciprocating fashion, either dry or immersed in liquid. It has also been adapted to measure yarn-on-yarn friction. The influence of spin finish on yarn friction and abrasion was investigated extensively. This study indicates that finish has a major effect not only on yarn performance but also on rope performance under the marine environment.

Testing Study on Wear Mechanism of Fluororubber by 45# Steel under Different Speed in Oil Medium

Fluororubber is an important material used for the stator of progressing cavity pump, which works under high temperature and high pressure conditions transferring oil of high viscosity. With sand-content oil as medium, the wear mechanisms of fluororubber by 45# steel under different speed and different initial temperature were investigated. On MPV-600 computer-controlled abrasive wear testing machine, the coefficients of friction (COF) were measured continuously for 10800s. The varying law of COF was summed up and the wear mechanism reflected was concluded.

Biomimetic Anti-Abrasion Surfaces of a Cone Form Component Against Soil

The geometrical surfaces of soil-burrowing animals were imitated and modeled on a cone component, the measuring tip part of a soil cone penetrometer. These biomimetic surfaces are concave dimples, convex domes and two wavy forms. The conventional cone surface and the biomimetic cone surfaces were analyzed in ANSYS 11.0 program to estimate cone equivalent stress and soil equivalent stress. Results show that biomimetic surfaces with the geometrical structures have lower cone equivalent stresses and soil equivalent stresses than that with conventional (smooth) surface. The least maximum cone equivalent stress and least maximum soil equivalent stress were recorded for biomimetic surfaces with concave dimples and wavy form-2 respectively. The two-body abrasive wear of biomimetic cone surfaces and conventional (smooth) cone surface were run on a rotary disk type of abrasive wear testing machine. The biomimetic cone surfaces were found to have lower abrasive wear than the conventional surface. It was found that and biomimetic cone surface with concave dimples has the lowest abrasive wear among the all tested surfaces.

Study of Compatibility of the Nano Lubricating Additives with the Electroless Deposited Ni-W-P Coating

Tribological properties as well as antiwear and friction reduction mechanism of wear self repair nano-ceramic and nano-Cu lubricating additives are researched using ring-block abrasion testing machine and Energy Dispersive Spectrometer. Research results show great difference between friction reduction performances of the above two additives, because their friction reduction mechanism are different, the former is ball bearing effect and the latter is soft film shear effect. In terms of wear-resistance, as for 45 steel, under heavy load, the self repair rate to the worn surface with the nano additives is less than the wearing rate of the friction pair. An effective way to solve the problem is electroless deposited Ni-W-P alloy coating on the surface of the 45 steel. The Ni-W-P alloy coating has high hardness, high wear resistance, and has excellent compatibility with nano lubricating additive, the wear resistance of Ni-W-P alloy coating (with heat treatment and the oil with nano additives) has increases hundreds times than 45 steel as the metal substrate with basic oil, zero wear is achieved, which break through the bottleneck of previous separate research of the above-mentioned the two.

Thermal conductivity and tribological properties of POM‐Cu composites

AbstractThe polyoxymethylene (POM) composites with different copper contents were prepared by extrusion. The thermal conductivity and tribological behavior of POM‐Cu composites with various contents of copper particles were investigated by a hot disk thermal analyzer and an M‐2000 friction and abrasion testing machine, respectively. The effect of copper particles on the thermal conductivity of POM composites was negligible when copper content was below 10 wt %. As the copper content increased, the thermal conductivity of composites increased and reached 0.477 W m−1 K−1 for POM‐25 wt % Cu composite, which increased by 35.9% compared with that of unfilled POM. The incorporation of copper particles into POM reduced the friction coefficient of POM composites. The wear mechanisms of POM‐Cu composites were adhesive and abrasive wear. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers

The Abrasive Effect of a Porcelain and a Nickel–Chromium Alloy on the Wear of Human Enamel and the Influence of a Carbonated Beverage on the Rate of Wear

This study was conducted to determine the abrasive effect of a porcelain and an Ni-Cr alloy on the wear of human enamel, and the influence of a carbonated beverage on the rate of wear. Tooth specimens were prepared by embedding 48 freshly extracted mandibular first premolars in acrylic. Twenty-four of these specimens were abraded against Ni-Cr, and the remaining 24 against porcelain in artificial saliva and carbonated beverage media, respectively (n = 12), on a specially designed abrasive testing machine at a constant load of 40 N with 6 mm amplitude for 15,000 cycles. The cusp heights of the tooth specimens were measured both before and after abrasion using a profile projector. The abraded cast specimens were subjected to profilometry for computing the surface roughness; the abrading media was subjected to atomic absorption spectrophotometry for analyzing Ni and Cr ion levels. Data obtained were statistically analyzed. Porcelain specimens in a medium of carbonated beverage caused the highest wear of tooth specimens. The lowest wear of tooth specimens was Ni-Cr specimens in artificial saliva medium. Carbonated beverage caused significantly higher wear of tooth specimens when abraded against Ni-Cr and porcelain specimens than did artificial saliva. The mean quantitative surface roughness of porcelain specimens was significantly higher than that of Ni-Cr specimens, irrespective of the medium in which abrasion testing was conducted. There was no statistically significant difference between the concentrations of Ni ions released in artificial saliva and carbonated beverage media. Also, there was no statistically significant difference between the concentrations of Cr ions released in artificial saliva and carbonated beverage media. The wear of human enamel was significantly higher in the presence of carbonated beverage than artificial saliva and against porcelain when compared with Ni-Cr. The surface roughness of porcelain in the presence of carbonated beverage was found to be highest, and the release of Ni and Cr was not affected by carbonated beverage.

Influence of CeO 2 on the microstructure and wear resistance of iron-based alloy coating studied by Rietveld refinement method

Iron-based alloys containing 0 wt.% and 3 wt.% CeO 2 (CeO 2-free and CeO 2-modified, respectively) particles were deposited on Q235 low carbon steel using plasma transferred arc (PTA) welding machine. Microstructures of the two coatings were studied by X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM) with energy dispersive X-ray energy spectrometer (EDS), and transmission electron microscope (TEM). More details about the phase compositions and abundance of the deposited coatings were obtained with the application of the Rietveld refinement method to analyze XRD patterns. Wear resistance experiment was conducted on one dry sand abrasion test (DSAT) machine to value the coatings. The results show that the CeO 2-free coating consists of γ (Fe, Ni), (Cr, Fe) 7C 3, and (Cr, Fe) 2B phases. Comparing with the CeO 2-free coating, adding 3 wt.% CeO 2 not only leads to appear CeO 2 phase except for those phases that existed in CeO 2-free coating, but increases the relative contents of the total Cr-rich compounds by 14.8%, and refines the microstructure of the iron-based alloy coating. The microstructure change, the variation in phase compositions and abundance are responsible for increasing the abrasive wear resistance of the CeO 2-modified iron-based alloy coating.

Investigation of Material Removal and Grain Wear Mechanism in Single Point Diamond Scratching Tests on SiC

There has been increased interest in the use of SiC due to its excellent physical and mechanical properties. The diamond grinding process of SiC has been largely investigated in recent years, but the interface between diamond grain and SiC in grinding has not been completely understood. In this paper, a single diamond scratching method was presented in order to insight into the interface realizing on a SRV friction and abrasion test machine using three types of diamond grains with different shapes. The results analysis for material removal and diamond grain wear mechanisms in the interacting between the diamond grain and SiC can be useful to improve the grinding process of SiC.

Synthesis and characterization of laser-based direct metal deposited nano-particles reinforced surface coatings for industrial slurry erosion applications

A nano-based material system resistant to the impingement of solid and liquid particles on the solid surfaces was developed by the laser-based direct metal deposition (LBDMD) process. The nano-based materials system contains 5% tungsten carbide (WC) nano-particles that are agglomerated with nickel–tungsten carbide 60 (Ni–Tung 60) by ball mill operation for slurry erosion resistance applications. Slurry erosion tests are performed on the LBDMD processed depositions using the ceramic proppant at different impingement angles using the abrasive water jet erosion testing machine. From these tests the amount of material removed, depth of penetration, and profile of the formed crater are computed as a function of the abrasive water jet impingement angles. The nano-based materials system exhibited better performance for slurry erosion resistance than the monolithic Ni–Tung 60 depositions and 4140 steels. In order to understand the role of the WC nano-particles influence on slurry erosion resistance and to understand the characteristic features of erosion surfaces, sub-surfaces, and the erosion mechanism, different advanced characterization tools are used.

Reduction of soil resistance through the use of a composite coating

Generally, soil seriously resists the motionn of soil-engaging components of terrain machines and tillage equipment because soil has such strong adhesion. In order to develop a method to treat this problem, a polysiloxane/T8 composite coating was used in this study. The wettability of steel 45, steel T8, polysiloxane coating, and polysiloxane/T8 composite coating was measured using a contact angle testing instrument (JCC-1, made in China) at 20°C in air. The abrasive wear resistance of both steel 45 and polysiloxane/T8 composite coating was tested on a turnplate abrasive wear testing machine. The resistance of soil to bulldozing plates made of the aforementioned materials was measured on bulldozing resistance testing equipment. The experimental results showed that the polysiloxane/T8 composite coating had excellent hydrophobicity, and that the contact angle of water on its surface reached up to 92°, which is much larger than that of steel 45 and steel T8. The relative volume wear loss of the polysiloxane/T8 composite coating was 65% and its bulldozing resistance was reduced by 15.2%–22.3% compared to bare steel 45.

Two-Body Abrasive Wear of the Outside Shell Surfaces of Mollusc Lamprotula fibrosa Heude, Rapana venosa Valenciennes and Dosinia anus Philippi

Natural biological surfaces and biomaterials have some distinguishing properties for adapting themselves to natural surroundings. The outside shell surfaces of mollusc species often undergo the abrasive wear action from the sand particles in water sand slurry in natural conditions. The two-body abrasive wear behavior of the outside shell surfaces of three mollusc species Lamprotula fibrosa Heude, Rapana venosa Valenciennes and Dosinia anus Philippi was examined. Abrasive material used for tests were quartz sand (96.5 wt.%) with three different size ranges and powdered bentonite (3.5 wt.%). The two-body abrasive wear tests were run on a rotary disc type abrasive wear testing machine. The results showed that the abrasion resistance of the outside shell surfaces of the three mollusc species was higher when the corrugations on the shell surfaces were perpendicular to the sliding direction of the abrasive material than that when the corrugations on the shell surfaces were parallel to the sliding direction of the abrasive material. Basically, the shell of Lamprotula fibrosa Heude possessed the highest abrasion resistance among the three species of shell; the abrasion resistance of the shell of Rapana venosa Valenciennes was the lowest; and the abraded depth of the three species of shell increased with an increased abrasive particle size and relative sliding velocity. The abraded surfaces were observed with scanning electron microscope.

Effects of vascular fiber content on abrasive wear of bamboo

Natural biomaterials have unique structures and some distinguishing properties for adapting themselves to natural surroundings. Bamboo is a natural composite reinforced with longitudinal fibers (vascular fibers). The abrasive wear property of the cross section of bamboo ( Phyllostachys pubescens) stem was examined. The abrasive material used for tests was the mixture of quartz sand (96.5 wt.%) and powdered bentonite (3.5 wt.%) and contained a water content of 3 wt.%, simulating soil condition The size of the quartz sand particles was 0.104–0.214 mm, 0.214–0.420 mm and 0.420–0.840 mm, respectively. The abrasive wear tests were run on a rotary disk type of abrasive wear testing machine. The relative sliding velocity was 1.68, 2.35 and 3.02 m/s, respectively. It was concluded that the abrasive wear resistance of the cross section of the bamboo stem was a function of the vascular fiber content of bamboo, the abrasive particle size and the relative sliding velocity. The wear resistance of bamboo was increased with its vascular fiber content. A higher sliding velocity or a larger abrasive particle size resulted in a higher abraded volume of bamboo. The effects of the tensile strength and the impact strength of bamboo on its abrasive wear were discussed. It was found by scanning electron microscopy that the geometric morphology of the abraded surfaces of the sections of bamboo stem displays a not-smooth structure. This not-smooth surface morphology provides a clue to develop anti-abrasion morphological surfaces of soil-engaging components.

Influence of Al 2O 3 reinforcement on the abrasive wear characteristic of Al 2O 3/PA1010 composite coatings

In the present study, the abrasive wear characteristics of Al 2O 3/PA1010 composite coatings were tested on the turnplate abrasive wear testing machine. Steel 45 (quenched and low-temperature tempered) was used as a reference material. The experimental results showed that when the Al 2O 3 particles have been treated with a silane coupling agent (γ-aminopropyl-triethoxysilane), the abrasive wear resistance of Al 2O 3/PA1010 composite coatings has a good linear relationship with the volume fraction of Al 2O 3 particles in Al 2O 3/PA1010 composite coatings and the linear correlation coefficient is 0.979. Under the experimental conditions, the size of Al 2O 3 particles (40.5–161.0 μm) has little influence on the abrasive wear resistance of Al 2O 3/PA1010 composite coatings. By treating the surface of Al 2O 3 particles with the silane coupling agent, the distribution of Al 2O 3 particles in PA1010 matrix is more homogeneous and the bonding state between Al 2O 3 particles and PA1010 matrix is better. Therefore, the Al 2O 3 particles make the Al 2O 3/PA1010 composite coatings have better abrasive wear resistance than PA1010 coating. The wear resistance of Al 2O 3/PA1010 composite coatings is about 45% compared with that of steel 45.

磨耗によるセラミック系床仕上材料のすべりの変化の推定方法

The slipperiness is very important characteristic of ceramic floors. So, it is important to establish the estimating method for not only the initial slipperiness but the changing of slipperiness of ceramic floors due to abrasion. In this study the relation between the slipperiness and the surface roughness was investigated. Resulting in, the corelation between the surface roughness (Rpk) and the slip resistance (C.S.R) was cleared. And the abrasion testing machine was developed for the purpose of estimate the changing of slipperiness due to abrasion by means of Rpk and C.S.R.

Effect of resin monomer composition on toothbrush wear resistance.

The purpose of this study was to compare the toothbrush abrasion resistance of seven different experimental resins which were made by changing the composition of resin monomers. The experimental resins were made by mixing four kinds of dental resin monomers (Bis-GMA, UDMA, TMPT and TEGDMA), camphorquinone (1 wt%), dimethylaminoethyl methacrylate (2 wt%) and 2,6-di-tert-butyl-p-cresol (0.05 wt%). The resin specimens were stored in air for 2 weeks, and then put on a toothbrush abrasion testing machine. After 100000 strokes, the wear loss of each specimen was determined by weight change during the wear test. TMPT-TEGDMA resin showed the most wear resistance, while Bis-GMA- and UDMA-based resins showed increased wear resistance with an increased content of TEGDMA. Also, a inverse relationship between the microhardness number and the amount of wear of the respective resins was confirmed.

歯冠修復材によるこう耗を想定した実験的研究 実験条件について

The purpose of this study was to investigate the experimental conditions of in vitro attrition testing that can predict clinical performance of restorative materials in the occlusal contact area.The experiments were performed using the sliding abrasion testing machine developed in our department. The upper specimens, made of extracted sound human premolar teeth and a commercial posterior composite resin (Clearfil Photo-Posterior, Kuraray), were made into hemispherical shapes (five each). The lower specimens, made of extracted sound human maxillary anterior teeth, were flattened smooth with emery papers. A load was applied between the upper and lower specimens which were slid in solution under various different conditions. After the specimens were slid a certain number of times under load, wear was evaluated by measuring the width and depth of the lower specimens.The results showed that there was a considerable difference in the wear of tooth enamel between composite resin to enamel and enamel to enamel in every condition, and that the weight of load, kind of solution, and sliding speed all had an effect on the wear. The cause of this difference remains to be explored. A definite conclusion cannot be drawn due to the insufficient number of experiments, but experimental conditions that were similar to the actual condition in the oral cavity were obtained.

The design of an impact abrasion testing machine

By using a cam-fiat follower-impact shaft with a crank-flat rotating anvil system, the machine to be described can create various impact abrasion conditions to simulate a large range of industrial situations encountered in this field. The main features of the machine are the long working life of the flat rotating anvil, which works in the same way as that of the disc in a pin-on-disc wear tester, and the accurate control of both the impact energy delivered to the specimen and the total sliding distance of the specimen on the anvil. Statistical analysis of test results on the machine with EN24 steel and cast high manganese steel shows that the uncertainty of the population mean is within ±4.7% of the sample mean under a 95% confidence level of student distribution, which indicates a very good accuracy of test.

Textbook of dental pharmacology and therapeutics

A reciprocating abrasion testing machine was used to measure the mutual abrasion of light-cured composites and clasps in vitro. Composite specimens were produced by packing the material into hemispherical wells in a polytetrafluoroethylene block, light-curing for 20 seconds and conditioning in distilled water for one week. The composites tested included ultrafine, hybrid and conventional types. Nine clasp types were studied including cast and wrought, round and half-round, cobalt-chromium, stainless steel and gold. The tests were carried out at 37 °C. The vertical overlap (undercut) of composite and clasp was set at 0.25mm. Ten specimens were subjected to 14,500 traverses in each test Abrasion of composite was measured as weight loss and reduction in thickness of the specimens, while abrasion of clasps was measured as weight loss. Abrasion of the composites was greatest for the conventional type and least for the ultrafines, but in all cases the changes were small and unlikely to impair the clinical performance of clasps during several years' usage. The abrasion of the clasps by conventional composite was considerable and would be expected to cause a significant reduction in retention clinically.