Abrasive Load Research Articles

Simple Green Route to Performance Improvement of Fully Bio-Based Linseed Oil Coating Using Nanofibrillated Cellulose.

Due to their bio-based character, oil-based coatings become more and more prevalent in wood surface finishing. These coatings impart appealing optical and haptic properties to the wood surface, but lack sufficient protection against water and mechanical influences. The present study reports a simple green route to improve the performance of linseed oil coating by the addition of nanofibrillated cellulose (NFC). In order to achieve surface chemical compatibility with linseed oil, NFC was chemically modified with acetic anhydride and (2-dodecen-1-yl)succinic anhydride, respectively, using propylene carbonate as a solvent. NFC/linseed oil formulations were prepared and applied to wood substrates. The wear resistance of oil-coated wood surfaces was assessed by a newly developed test combining abrasive loading with subsequent contact angle measurement. As revealed by infrared and nuclear magnetic resonance (NMR) spectroscopy, as well as X-ray diffraction (XRD), NFC has been successfully modified without significantly affecting the structure of cellulose. In abrasion tests, all NFC-modified oil coatings performed better than the original oil. Interestingly, NFC only suspended in propylene carbonate, i.e., without chemical modification, had the strongest improvement effect on the coating’s wear resistance. This was primarily attributed to the loose network structure of this NFC variant which effectively prevents the oil from penetration into the wood surface, thus forming a protective NFC/oil composite layer on the wood surface.

Development of a wear-resistant flux cored wire of Fe-C-Si-Mn-Cr-Ni-Mo-V system for deposit welding of mining equipment parts

The effect of introduction of cobalt in the charge of the flux cored wire of Fe-C-Si-Mn-Cr-Ni-Mo-V system operating under abrasive and abrasive-shock loads is studied. In the laboratory conditions samples of flux cored wires were made, deposition was performed, the effect of cobalt on the hardness and the degree of wear was evaluated, metallographic studies were carried out. The influence of cobalt introduced into the charge of the flux cored wire of Fe-C-Si-Mn-Cr-Ni-Mo-V system on the structure, nature of nonmetallic inclusions, hardness and wear resistance of the weld metal was studied. In the laboratory conditions samples flux cored wire were made using appropriate powdered materials. As a carbon-fluorine-containing material dust from gas cleaning units of aluminum production was used. In the course of the study the chemical composition of the weld metal was determined, metallographic analysis was performed, mechanical properties were determined. As a result of the metallographic analysis the size of the former austenite grain, martensite dispersion in the structure of the weld metal, the level of contamination with its nonmetallic inclusions were established.

Quality of Metal Deposited Flux Cored Wire with the System Fe-C-Si-Mn-Cr-Mo-Ni-V-Co

Studied the effect of the introduction of vanadium and cobalt into the charge powder fused wire system Fe-C-Si-Mn-Cr-Ni-Mo-V, used in cladding assemblies and equipment parts and mechanisms operating under abrasive and abrasive shock loads. the cored wires samples were manufactured in the laboratory conditions and using appropriate powder materials and as a carbonfluoride contained material were used the dust from gas purification of aluminum production.

Effects of Fineness of Rubber Powder on Micro-Surfacing Performance

In order to research the effects of fineness of rubber powder on micro-surfacing, the control variable method was used. Through a series of basic performance tests, performance indexes such as mixing time, cohesion torque, wet track abrasion value and load wheel sand value were studied. The results showed that waste rubber powder with 40 mesh had good effects on non-construction time, anti-wear performance, the density and water sealed performance of micro-surfacing.

Effects of carbides on abrasive wear properties and failure behaviours of high speed steels with different alloy element content

High speed steels (HSSs) are effective materials applied in aggressive environments where abrasion resistances are required because they have hard carbides and relatively ductile matrix to bind carbides. But there are many kinds of carbides in HSSs, which lead to different effect on wear properties of HSSs. In this paper, three kinds of casting HSSs with VC, M6C or M2C type carbide were prepared respectively through the reasonable design of alloy elements, and then the effects of carbide type on wear behaviours were researched under different abrasive particle size and load using abrasive wear testing machine. The microstructures and failure behaviours of HSSs were analyzed by electron microscopy. The results showed the abrasive particle size and load had obvious effect on wear weight loss of high speed steel (HSS), but the carbide type decided the relative wear resistance of HSS. As the abrasive particle size or load increased, the wear weight loss of any HSS increased obviously. For the fine abrasive wear, the HSS with M6C had higher relative wear resistance than HSS with M2C. But the contrary was the case for the coarse abrasive wear. For any abrasive particle size and load, the HSS with VC had more excellent wear resistance than HSS with M6C or M2C type carbide. The relative wear resistance of HSS with VC was three times higher than that of HSS with M6C or M2C. The excellent wear resistance of HSS with VC was mainly attributed to VC characteristics, such as high hardness and good morphology, which can resist micro-cutting of abrasive particles efficiently.

Abrasive size and load effects on the wear of a 19.9% chromium and 2.9% carbon cast iron

The effects of applied loads and abrasive sizes on the wear of a 2.9% carbon and 19.9% chromium martensitic white cast iron were investigated. Abrasive wear tests using a pin test on silica and garnet papers (ASTM G132) were carried out using three different abrasive average sizes: 67μm, 149μm and 177μm and two applied normal load: 5N and 10N. A modified rubber wheel abrasion test (ASTM G65) was carried out using three abrasive average sizes - 90μm, 115μm and 170μm quartz sand - and three applied normal loads: 44N, 80N and 130N. The abrasive shape and the wear surface of the specimens were examined using a scanning electron microscope (SEM). The worn surfaces topography was obtained with a Taylor Hobson 3-D surface analyser. In the pin test with silica paper, a change in the magnitude of the volume loss was observed as a result of increasing the applied load from 5N to 10N. In the rubber wheel abrasion tests the mass loss increased with the increase of particle size until a critical particle size was reached. In general, the mass loss increased with the increase of the applied load and the abrasive size. For the lower load and the smallest abrasive size wear grooves were observed only in the martensitic matrix while the carbides remained intact. With higher loads and larger abrasives, scratching was observed also in the carbides. A wear map is proposed with a ‘wear rate’ parameter developed in this work plotted against abrasive sizes.

Wear resistance of WC/Co HVOF-coatings and galvanic Cr coatings modified by diamond nanoparticles

The efforts in the recent 20 years are related to search of ecological solutions in the tribotechnologies for the replacement of galvanic Cr coatings in the contact systems operating under extreme conditions: abrasion, erosion, cavitation, corrosion, shock and vibration loads. One of the solutions is in the composite coatings deposited by high velocity gas-flame process (HVOF). The present paper presents comparative study results for mechanical and tribological characteristics of galvanic Cr coatings without nanoparticles, galvanic Cr coatings modified by diamond nanoparticles NDDS of various concentration 0.6; 10; 15 и 20% obtained under three technological regimes, and composite WC-12Co coating. Comparative results about hardness, wear, wear resistance and friction coefficient are obtained for galvanic Cr-NDDS and WC-12Co coatings operating at equal friction conditions of dry friction on abrasive surface. The WC-12Co coating shows 5.4 to 7 times higher wear resistance compared to the galvanic Cr-NDDS coatings.

Development and use of mill scale briquettes in BOF

Generation of high iron containing wastes such as mill scale, dust and sludge are inevitable in steel making process. It is important to develop and implement processes to recycle and re-use these wastes. An attractive option is to recycle these wastes through BOF steel making process, but is not suitable for handling and efficient operation in available forms. Present work shows the briquetting of steel making wastes using various binders in a pilot scale briquetting machine. In briquetting tests, the effecting parameters have been studied for determining the best combination of binders and operating parameters. A process for briquetting mill scale in optimum combination with CRM dust and BOF dusts using an organic binder has been established. Separate indices were formulated as acceptance criterion for use of mill scale briquettes in BOF service conditions involving dynamic, crushing, abrasive and thermal loads. Subsequently, series of trials were conducted with use of mill scale briquettes as secondary coolant replacing iron ore in 130T LD converter. The present paper compares the effect of mill scale briquettes vis-à-vis iron ore on process parameters in BOF steel making and also highlights its operational advantages.

Comparison between PEEK and Ti6Al4V concerning micro-scale abrasion wear on dental applications

In the oral cavity, abrasive wear is predictable at exposed tooth or restorative surfaces, during mastication and tooth brushing. Also, wear can occur at contacting surfaces between the Ti-based prosthetic structures and implants in presence of abrasive compounds from food or toothpaste. Thus, the aim of this work was to compare the abrasive wear resistance of PEEK and Ti6Al4V on three-body abrasion related to different hydrated silica content and loads. Surfaces of Ti6Al4V or PEEK cylinders (8mm diameter and 4mm height) were wet ground on SiC papers and then polished with 1µm diamond paste. After that, surfaces were ultrasonically cleaned in propyl alcohol for 15min and then in distilled water for 10min. Micro-scale abrasion tests were performed at 60rpm and on different normal loads (0.4, 0.8 or 1.2N) after 600 ball revolutions using suspensions with different weight contents of hydrated silica. After abrasive tests, wear scars on flat samples were measured to quantify the wear volume and characterized by scanning electron microscope (SEM) to identify the dominant wear mechanisms. Results showed a higher volume loss rate on PEEK than that recorded on Ti6Al4V, when subjected to three-body abrasion tests involving hydrated silica suspensions. An increase in volume loss was noted on both tested materials when the abrasive content or load was increased. PEEK was characterized by less wear resistance than that on Ti6Al4V after micro-scale abrasion wear in contact with hydrated silica particles, as commonly found in toothpastes.

Rubberized Concrete Durability Against Abrasion

Durability performance of rubberized concrete against abrasion is presented in this paper. Surface depth loss was measured when abrasion load was constantly applied on concrete surface at each 500 interval rotation. Specimen with water-to cement ratio of 0.50 and 0.35 was prepared and tested at 28 days of curing age. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against wear when added with crumb rubber. Results showed that crumb rubber shows good potential in providing abrasion resistance to concrete mix. However, in the case of rubberized concrete with silica fume, abrasion resistance was found to be slightly decreased with compressive strength more than 50N/mm 2 due to the lack of low elastic modulus of CR particles to accommodate with denser cement matrix.

Tribological Analysis of Thermal Spray Coatings of Ni and Al2O3 with Dispersion of Solid Lubricants in Erosive Wear Modes

Thermal spray coating was found very stable even in erosion, abrasion, scratch and heavy load conditions. At elevated temperatures, it protects the solid lubricants entrapped in it and thus causes the layer to be stable and dynamic. In the present work, Ni and 60% wt. of Al2O3, were mixed in fixed proportion as thermal spray with entrapped solid lubricant through D–Gun on the substrate. The solid lubricants mixed in thermal spray were graphite and PTFE. The specimen was taken and cleaned properly and coated with thermal spray and solid lubricating coatings of 0.5 micrometer. These were then ultrasonically cleaned in the acetone bath. The coating is done by a duo spray pump that spurts the coating on the work piece. This pump spurting is controlled by a semi permeable membrane coated on the work piece. The coatings were evaluated for erosive wear performance. Coatings were tested at different air pressure, temperature and impingement angle. The Graphite and NiAl2O3 coating is found to be more stable tribologically as compared to PTFE and NiAl2O3 coating at high temperatures and pressures. Morphological analysis of coatings was also done.

Technical note: An in vitro study of dental microwear formation using the BITE Master II chewing machine.

Dental microwear has been used for decades to reconstruct the diets of fossil hominins and bioarchaeological populations. The basic theory has been that hard-brittle foods (e.g., nuts, bone) require crushing and leave pits as they are pressed between opposing cheek-tooth surfaces, whereas soft-tough foods (e.g., grass blades, meat) require shearing and leave scratches as they are dragged along opposing surfaces that slide past one another. However, recent studies have called into question the efficacy of microwear as an indicator of diet. One issue has been the limited number of in vitro studies providing empirical evidence for associations between microwear pattern and chewing behavior. We here describe a new study using a chewing simulator, the BITE Master II, to examine the effects of angle of approach between opposing teeth and food consistency on microwear surface texture. Results indicate that opposing teeth that approach one another: 1) perpendicular to the occlusal plane (crushing) result in pits; 2) parallel to the occlusal plane (shearing) result in striations in the direction of movement; and 3) oblique to the occlusal plane (45°) result in both striations and pits. Results further suggest that different food types and abrasive loads affect the propensity to accumulate microwear features independent of feature shapes.

First Experimental and Numerical Study on the Use of Sheet Metal Die Covers for Wear Protection in Closed-Die Forging

To reduce the failure of dies by abrasive wear, mechanical fatigue and thermal fatigue in closed-die forging usually measures like nitriding, deposition of ceramic layers by Physical Vapour Deposition (PVD), Chemical Vapour Deposition (CVD) or deposition welding are used. However, after some time wear appears and the dies have to be replaced. A new concept implements sheet metal die covers, which are placed on the die engraving during forging and will absorb abrasive wear, thermal and mechanical load. The inexpensive cover will be replaced quickly by a new one after it is worn-out. This concept is regarded in a first numerical and experimental study by comparing a covered die (C) and an uncovered die (U) for the production of the same part. A one-time use of the die cover showed a reduction of the peak temperature by 140 K and of the temperature amplitude by 37 %. The temperature reduction and the increase of inner radii of the engraving to fit the 1mm thick die cover doubled the expected die life time. The experiment showed that the soft deep drawing steel DC04 is not suitable in the current case for a die cover and a higher strength sheet metal should be applied.

Effect of Plating Additives on Microstructure and Properties of Electrodeposited Ni-Fe Alloy

With the evolving technology, the frame mounted design of electronic components has increasingly become high-density, which leads to the electronic elements that are inevitably vulnerable to electromagnetic interference and then affect other electronic products’ functions. The solution is to use well conductive material that operates the shielding process. The material includes metals and conductive polymers which are common sources of the protective materials in dealing with the main conductive surface. Although this masking method has been widely recognized, several problems are still observed in practice, including the vulnerability to scaling, abrasion, corrosion and process load. In this study, we adopt Ni-Fe alloy film as the shielding material and manufacture it by electroplating. We intend to explore the effects of plating solution composition, plating parameter and plating additives on structural strength and magnetic properties of the Ni-Fe alloy film. In electroplating, plating additives play important roles. The results suggest that various additives lead to different crystalline orientations, grain sizes, and surface roughness. A correlation between the plated structure and the magnetic properties is studied. Additionally, anti-corrosion is improved by doping a few boron in the film. The ultimate goal of the study is to meet the requirements of electronic industry in manufacturing Ni-Fe alloy with high permeability and good corrosion resistance.

Synthesis of wear-resistant superhydrophobic coatings via laser micro- and nanotexturing

We describe a method for texturing the metal surface in order to impart it a multimodal roughness necessary to meet the requirements for achieving the superhydrophobic state of the surface. This technique is based on micro- and nanotexturing of the surface via nanosecond laser treatment, and it can easily be automated and scaled up to process metal parts with a large area and a complicated surface profile. The experimental testing under model cavitation and abrasive loads reveals the high mechanical durability of superhydrophobic coatings, unlike their conventional counterparts. The basic factors that ensure improved exploitation performance of the developed coatings are defined and briefly discussed.

Effect of PCBN tool grade and cutting type on hard turning of high-chromium white cast iron

The turning of mechanical construction and bearing steels is widely carried out using PCBN and oxide ceramic tools, even when materials have high hardness (40 to 60 HRC), reached after quenching and tempering heat treatment. However, mechanical components submitted to severe abrasive loads show, in addition to matrix hardness, the presence of a high-volume fraction of hard particles in the microstructure. Turning materials with a high content of hard particles in the microstructure will result in high rates of abrasive wear or damage to the cutting edges of the tool. Information regarding the turning of materials characterized by a high-volume fraction of carbides in the microstructure is limited in literature. The objective of this study was to determine the performance of two grades of PCBN tools (high CBN and low CBN content with an added ceramic phase) in the turning of high-chromium white cast iron applying continuous and interrupted cutting. Evaluations of tools’ life, wear mechanisms at the tool cutting edges, roughness, and microstructure remaining on the turned surface were carried out. The results show that the grades with low CBN content and the addition of a ceramic phase, the tool life was three times longer than that of the grades with high CBN content. The most interesting result obtained concerns the microstructural modifications in a narrow subsurface layer of the turned material. Carbide fragmentation and alignment in the direction of the cutting shear plane were identified, which may potentiate the use of the material.

Effect of Plating Additives on Microstructure and Properties of Electrodeposited Ni-Fe Alloy Thin Film

With the evolving technology, the frame mounted design of electronic components has increasingly become high-density, which leads to the electronic elements that are inevitably vulnerable to electromagnetic interference and then affect other electronic products’ functions. The solution is to use well conductive material that operates the shielding process. The material includes metals and conductive polymers which are common sources of the protective materials in dealing with the main conductive surface. Although this masking method has been widely recognized, several problems are still observed in practice, including the vulnerability to scaling, abrasion, corrosion and process load. In this study, we adopt Fe-Ni alloy film as the shielding material and manufacture it by electroplating. We intend to explore the effectiveness of changing the plating bath composition, plating parameter and plating additives on structural strength and magnetic properties of the Fe-Ni alloy film. Different proportions of nickel and iron ion concentration and content of H3BO3 cause different proportions of electrodeposited elements in the film. And the higher content of nickel ion will have higher permeability. In magnetic electroplating, plating additives play an important role. The findings suggest that various additives lead to different crystalline orientations, grain sizes, surface roughness. A strong correlation is also shown between the observed structural changes and the changes in the magnetic properties, such as permeability. Additionally, anti-corrosion is a significant issue. We can improve the corrosion problem by doping little element such as Boron in the film, obtain the corrosion potential and corrosion current by Tafel analysis. The ultimate goal of the study is to meet the requirements of electronic industry in manufacturing high permeability and optimum corrosion resistance for shielding material Fe-Ni alloy film.

Analysis of abrasive wear behavior of PTFE composite using Taguchi’s technique

AbstractPolymeric composites are widely used for structural, aerospace, and automobile sectors due to their good combination of high specific strength and specific modulus. These two main characteristics make these materials attractive, compared to conventional materials like metal or alloy ones. Some of their typical benefits include easy processing, corrosion resistance, low friction, and damping of noise and vibrations. Wear behavior of Polytetrafluoroethylenes (PTFE) and its composites including glass-filled composites and carbon-filled composites are investigated using a pin-on-disc configuration. A plan of experiments in terms of Taguchi technique is carried out to acquire data in controlled way. An orthogonal array (L9) and the analysis of variance are employed to investigate the influence of process parameters on the wear of these composites. Volume loss increased with abrasive size, load, and distance. Furthermore, specific wear rate decreased with increasing grit size, load, sliding distance, wh...

A Material Removal Rate Model for Aluminum Gate Chemical Mechanical Planarization

In this work, a new aluminum gate chemical mechanical planarization (CMP) model for material removal rate (MRR) is proposed in high-k metal gate (HKMG) process. Using the basic principles of steady-state oxidation reaction and mechanical abrasion mechanism, the combinational interaction of chemical and mechanical coupled effects on MRR was systematically described by process parameters, pad properties and concentration of oxidizer, and then balanced to construct an overall polishing rate. Because of the great significance of the slurry pH on MRR in CMP process, the effects of surface forces, including the influences of van der Waals (vdW) and double-layer (DL) forces simultaneously acted between the wafer and the particles were investigated. Meanwhile, the influence of particle sizes, abrasive loadings and zeta potentials of the wafer and particles on MRR was also analyzed. It is found that the attractive vdW forces strengthen the MRR, while the DL forces, calculated to be repulsive, lower the MRR. The magnitude of surface forces increases with a smaller particle size compared with the pad-particle force. When zeta potentials of the wafer and particles are considered as a function of slurry pH, the experimental trends for the MRR with slurry pH, applied pressure and abrasive loading were predicted well by the present model. Therefore, the governing equation of aluminum removal reveals some insights into the HKMG CMP process and can be utilized for optimizing and controlling the polishing rate of aluminum gate structures and performing sensitivity analyses of operating parameters.

Assessment of the Suitability of Paper Waste as an Engineering Material

This research work investigates the potential applicability of waste paper in the production of ceiling boards with focus on achieving: environmental sustainability, safe disposal of waste paper and more cost effective production of materials. The main view was to provide an alternative to the conventional asbestos ceiling boards that are costly and also pose health risks. Three mix designs were formulated and used for the casting (1:1, 1:1.5 and 1:2), varying in regards of the weight of the waste paper components. CaCO3 was added to the mix as an additive as well as starch bond glue to aid binding. Laboratory experiments were conducted to determine the properties and suitability of the produced boards. Properties such as water absorption, abrasion, compressive strength, flexural strength and ultimate loads were considered for comparison. The boards with 1:1 mix ratio displayed the best results of the test properties hence, its mechanized manufacturing was recommended.