Impact Abrasion Research Articles

Protocol to assess the quality of transmission lines within smart textile structures

The washability issue is always a challenge for electronic textiles in terms of application. It reduces their reliability, makes them not robust enough, and therefore not ready for the market. In this study, a novel protocol was designed to test the performance of conductive threads under wet situation in order to simulate the washing cycle. In this content, two commercially available silver-plated polyamide threads having the same thread count were used and washing results of each thread were discussed. Transmission lines with silver-plated polyamide threads onto cotton woven fabric were produced via sewing (single-line stitch) and embroidery techniques (three-line stitch) to improve the conductivity and robustness. For the simulation of the wash process, Martindale abrasion tester was used under wet and dry conditions. Moreover, felts of abrasion tester and transmission lines were put into different solutions, i.e., water, water with standardized detergent and water with commercially available detergent. After wetting specimens, abrasion tests were performed on transmission lines, and linear electrical resistance measurements were recorded with the multi meter before abrasion and every 1500 cycles up to 4500 cycles in wet conditions and also after drying the transmission lines. Finally, abrasion impact on silver-plated polyamide threads was investigated by optical microscope. It has been found that silver coating on the conductive thread was damaged when subjected to abrasion cycles, especially in wet states. Water itself has stress impact on samples provoking the electrical resistance increase rapidly. Commercial detergent with water was found to have the most damaging effect on the conductive threads because of extra particles presence to enhance the washing performance. In terms of integration methods, better electrical conductivity values were achieved in three-line embroidery transmission lines due to multiple interconnection points in the embroidery network.

Effect of Carbon Content on Abrasive Impact Wear Behavior of Cr-Si-Mn Low Alloy Wear Resistant Cast Steels

The effects of carbon contents on wear resistance were investigated for Cr-Si-Mn low alloy cast steels. The abrasive impact wear behavior was also analyzed. The results showed that, with the increase of carbon content in steels, the metallographic structure partly transformed from lath martensite to acicular martensite gradually, the hardness increased and the impact toughness decreased distinctly, furthermore, wear resistant first increased and then decreased, that was mainly caused by the wear mechanism changed form plastic fatigue wear to brittle fracture wear.

Disaster mapping as decision support system to decrease abrasion impact due to climate change in Bantul Coastal Area

Global climate change affects the physical condition of coastal areas, one of which is the rise in wave height. The increase in wave height allows higher volume of carried substrate on the swash and backwash motions. These events have an impact on increasing the abrasion intensity, specifically on the coastal areas which consist of sand material (beaches). Coastal area of Bantul Regency is one of the areas exposed to abrasion because it is directly facing the Indian Ocean. Application of atmospheric science and technology is needed to reduce the impact of losses caused by abrasion. Disaster mapping is an effort to reach that expectation. This research aimed (1) to identify abrasion susceptibility, and (2) to analyse social vulnerability due to abrasion in Bantul coastal area. The assessment was done by GIS-based spatial-multi criteria analysis to process physical and socio-cultural aspects in regards of abrasion, which the analytical unit was the coastal area between Opak and Progo River estuaries. This research resulted in susceptibility map and social vulnerability map as references for coastal mitigation directives supporting the resilience of region and community towards climate change.

ПОДШИПНИКИ СКОЛЬЖЕНИЯ ИЗ АРМИРОВАННЫХ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ

The aim of the work is a design substantiation of sliding bearings with wedges made of new antifriction reinforced wood-metal materials having increased tribo-technical properties ensuring potentialities for their industrial use widening. 
 The wear investigation of the materials offered was carried out according to the procedure providing for an abrasive impact at that besides wear-resistance the thermo-physical characteristics of samples under analysis were assessed. As a result of the investigation there was offered a structure of anti-friction materials combining in them modified wood and a metal filling agent made of different antifriction materials or special capsules filled with fusible materials and also wedges made by means of a joint coiling of a metal band or an element as tensile anti-friction springs and sized bands of veneer.
 The offered reinforced composite sliding bearings allow ensuring higher mechanical and tribo-technical characteristics to a considerable extent, optimizing a thermal working mode of sliding bearing wedges, increasing considerably their manufacturability and widening a sphere of industrial use by means of rational combining different wood types and metal composite constituents.

Optimization of Vanadium Content for Achieving Higher Wear Resistance and Hardness in High Cr-V White Cast Irons for Ball Tube Mill Liner Application

The liner materials, being used, at present from high Cr cast iron grades in coal fired tube mills are less promising due to lower combination of abrasion wear resistance, hardness and impact toughness properties, thus giving life of only 25,000 to 35,000 hours. In this study, focus was given to develop a high Cr-V cast iron of high abrasion wear resistance with higher hardness and impact strength for ball tube mill liner application. The developed liner possesses high abrasive wear resistance and impact resistance simultaneously for having life of 40,000 to 50,000 hours. This grade was made using induction melting and sand casting method. The casting was heat treated in two stages to achieve higher abrasion wear resistance and mechanical properties. Various tests like chemical analysis, abrasion wear, hardness and impact tests were conducted on the above developed material. Abrasion wear test results show a low wear loss value (2.7 to 4.4 mg/min). Hardness and impact tests show a high combination of hardness (57 to 64 HRC) and impact strength (44 to 57 J/cm2). Prototype tube mill liners were manufactured and tested in a tube mill at 250MW site. Results obtained from site testing are also discussed in this study.

Rational design of HSNs/VO2 bilayer coatings with optimized optical performances and mechanical robustness for smart windows

For vanadium dioxide (VO2)-based smart windows, insufficient optical performances, including luminous transmittance (Tlum) and solar modulation efficiency (ΔTsol), have always been the main problems hindering their practicality as energy-efficient windows, which have attracted numerous studies in recent years. However, the improved Tlum are always obtained at the expense of ΔTsol, and vice versa. In this work, we report a controllable interfacial engineering strategy for the fabrication of multifunctional hollow SiO2 nanospheres (HSNs)/VO2 bilayer coatings with tunable optical performance and mechanical robustness on the basis of finite difference time domain (FDTD) calculation. The theoretical calculation predicted that the Tlum of the bilayer coatings can be enhanced from 42.7% to 55.2% without sacrificing the ΔTsol. Surprisingly, experiments showed that not only the Tlum of the optimized bilayer coating increased to 53.8% from 21.4%, but also the ΔTsol enhanced from 9.8% up to 17.2%. It is believed that the outstanding optical performance comes from the low refractive index of HSNs as well as good dispersibility of VO2 nanoparticles. Moreover, the pencil hardness test, tap peeling test and sand impact abrasion test showed remarkable mechanical robustness of the bilayer coating, which makes it highly attractive for application in the windows of high-rise buildings.

Optimization of arc-sprayed iron-based tungsten carbide hard coatings on harvester blades

This research investigated the viability of improving the performance of agricultural harvester blades by thermal spray, utilizing the arc spray process. A cored iron-based wire with recycled WC was used with several process parameters in order to determine the best WC distribution in the coating. The effect of 40 V voltage was compared to 30 V on electric arc-sprayed coatings, and the results show that 40 V provides higher tungsten carbide (WC) content. Flame remelting of the arc-sprayed iron-based WC coatings on sugarcane harvester blades was studied, and the changes in the microstructure and impact abrasion wear behavior were analyzed. The coatings were characterized by utilizing microstructural analysis and microhardness indentation tests. In order to verify the coating adhesion strength, a special machine was built to simulate field conditions. This machine, called impact abrasion test machine, was used to test the blades for coating detachment due to low adhesion strength. The results showed that the flame remelting provided metallurgical bonding between the coating and substrate, improving the impact wear resistance and potentially extending the lifetime of sugarcane harvester blades.

Повышение срока эксплуатации литых броней из высокомарганцевой стали мельницы полусамоизмельчения

At the processing plants of the mining industry, a significant part of the total processing costs (from 45 to 65%) is spent on crushing and grinding operations, including mill lining. The efficiency of grinding equipment in the conditions of abrasive impact of ore and a continuous operation requires periodic replacement of a worn-out lining. The costs for its purchase, delivery and installation during a year amount to tens of millions of rubles, and the equipment downtime associated with the replacement of the lining reduces the volume of finished products by hundreds of millions of rubles per year. The practical efficiency of imported mill liners is not always confirmed by the expected positive result of their actual operation, and an increase in the equipment utilization coefficient (EUC), but their use definitely requires significant financial costs and entails risks in an unstable political and financial situation. Therefore, the task of increasing the service life of the mill liners is urgent. The paper presents a suggested and implemented solution to increase the lifetime of 110G13L steel lining for the wet semi-autogenous grinding mill (SAG mill-70х23). It includes monitoring of the actual liner operation and a mathematical simulation of the ore and ball trajectory in the mill, reveals zones of intensive wear, defects of liner castings and developed new structures of the lining elements. Applying the simulation software package, the authors studied the existing casting technologies, found reasons for defects and developed the casting technology for a new design of liners excluding defects. The paper contains industrial tests of the liners of a new design manufactured according to the developed technologies.

Evaluation Method of Impact and Abrasive Steel Resistance

A technique is developed for evaluating the impact-abrasive resistance of cast specimens, which allows simulating the conditions of impact and abrasive wear when changing the following factors: impact energy, abrasive impact angle, abrasive type, and its consumption and grain size. The complex experiment results for five carbide-promoting elements effect on abrasive (AR), impact and abrasive (IAR), and antifriction (AFR) steel resistance in the cast and hardened states are presented. The possibility of using the new technique for evaluating wear resistance and optimizing the composition of steel operating under impact-abrasive effects is shown.

Relationship among operational parameters, ore characteristics, and product shape properties in an industrial SAG mill

A detailed test work was carried out with an industrial semi-autogenous (SAG) mill in a copper plant in close and open circuits to specify the effects of ore characteristics and operational parameters on mill performance. In addition, the shape of mill product particles was studied to monitor breakage events as a function of ore strength. For this purpose, the strength properties of the SAG mill feed and product were specified by different techniques, including the point load index, impact breakage parameters (A × b), abrasion index (ta), and Bond ball mill work index (Wi). Experimental studies showed that an increase in ore hardness is linked with an increase in point load index and Bond work index and a decline in impact breakage parameter (A × b). Hard ore grinding resulted in finer products, compared to the soft ore milling. The softer ore is ground chiefly via the impact breakage whereas the stronger ore is subjected to abrasion and attrition events where the media impact could not sufficiently break the stronger particles. The main reason for the decrease of circuit throughput was changes in breakage mechanisms. The results displayed that the highest aspect ratio and the lowest circularity of mill product are achieved by soft ore milling. As ore strength changes, differences in shape can be attributed to the different breakage mechanisms operated in the mill. In addition, the particle shape characteristics provide a convenient way to quantify changes in SAG mill as a function of the ore properties and the kind of breakage action used.

Estimation of application efficiency of “Flumag M” magnesia flux in agglomeration and BF production.

To decrease viscosity of BF slag and improve its desulfurization ability during hot metal production a magnesia oxide is used, which is introduced into a blast furnace, as a rule, within iron ore sinter, as well as in the form of a fluxing additive. Dolomite, sometimes iron ore materials with increased magnesia content (for example, Kovdor concentrate, raw or roasted Bakal siderite) as well as magnesia-contained wastes, most often BOF slag, are usually used as a main source of magnesia oxide during iron ore sinter production. Brucite, which is widely used abroad, mainly in Japan during iron ore sinter production, is a very prospective magnesia flux. However, brucite was never used in sinter production in Russia. Main parameters and efficiency of its application were obtained under Japan raw materials conditions. However sinter chemical and mineral compositions at Russian and Japanese sinter plants considerably differ. In this connection studies on influence of the magnesia flux “Flumag M”, which is identical by its composition to brucite, on the process parameters of sinter burden sintering and pellets production were carried out. The estimation of application efficiency of “Flumag M” magnesia flux was made during typical sintering of NLMK sinter burden. It was determined, that partial and complete substitution of dolomite by the “Flumag M” magnesia flux in the NLMK sinter burden results in an increase of specific productivity of sintering process by 10–20% (comparative) and the sinter strength by 3–5% (comparative) correspondently. Laboratory experiments on “Flumag M” magnesia flux application, carried out in STI NITU “MISiS”, showed, that raw pellets with magnesia flux additives have higher compressive strength comparing with the pellets having dolomite additives. Impact strength and abrasion strength of roasted pellets is higher, comparing with those with dolomite. Optimal content of “Flumag M” flux in the pellets burden is 2%. The application of “Flumag M” magnesia flux enables to remove burden from the burden and increase strength of roasted pellets.

Effect of Particular Combinations of Quenching, Tempering and Carburization on Abrasive Wear of Low-Carbon Manganese Steels with Metastable Austenite

The effect of quenching from 900°C (20 min exposure) and different tempering in the 250-650°C (for 1 hour) interval, as well as additionally preliminary carburization for 8 hours at 930°C, followed by a similar heat treatment on abrasive and shock-abrasive wear of low-carbon manganese (10-24%Mn) steels, phase composition and mechanical properties was studied. It was confirmed that an increase in the manganese reduces the abrasive wear resistance and increases the impact-abrasive wear resistance. The expediency of carburization of low-carbon manganese steels is shown in order to obtain the residual austenite in the structure which amount and stability must be optimized in relation to specific abrasive impact characterized by the dynamic ratio with taking into account the chemical composition.

Investigating hollow corundum microspheres exfoliation of the elastomeric matrix

The results of study of the influence of hollow corundum microspheres HCM-S (5–100 µm) and HCM-L (70–180 µm) on the properties of nitrile butadiene rubber BNKS-18 are presented. The dependence of elastomer resistance to abrasion impact and physic and mechanical properties on the dispersion and concentration of hollow corundum microspheres is shown. The process of hollow corundum microspheres exfoliation of the elastomeric matrix, which largely determines the change of physic and mechanical properties, has been studied by specially developed stretching device compatible with an atomic force microscope. The paper describes microspheres exfoliation which is conventionally divided into 3 stages.

Effect of thermo-mechanical processing on the low impact abrasion and low stress sliding wear resistance of austenitic high manganese steels

The low impact abrasion and low stress sliding wear properties of two thermo-mechanically processed austenitic high manganese steels (Fe17Mn and Fe17Mn3Al) have been studied. It is observed that the application of thermo-mechanical processing (TMP) can significantly improve the low impact abrasion and low stress sliding wear resistance of both the steels. Thermo-mechanically processed Fe17Mn steel shows higher impact abrasion and sliding wear resistance compared to the thermo-mechanically processed Fe17Mn3Al steel. For both the steels, the impact abrasion wear mechanisms are cutting and spalling. However, in the case of low stress sliding wear, an oxidation type of wear is observed.

Histological indicators of cutaneous lesions caused by electrocution, flame burn and impact abrasion.

Cutaneous electrocution marks are the key indicator that aid forensic pathologists in establishing electrocution as the cause of death, especially when crime scene and internal autopsy findings do not provide significant information. The gross findings of electrocution mark are often confused with impact abrasion and the burns produced by high voltage flash are often indistinguishable with flame burns. The present study aims to identify cutaneous light microscopic histological indicators, which are peculiar to electrocution marks, burns and impact abrasions. Cutaneous tissue samples from injury sites and healthy areas were collected from 45 autopsy cases and examined under light microscope. The histological changes observed were intra-epidermal separation of cells, sub-epidermal separation, coagulative necrosis in the epidermis and dermis, epidermal and dermal cell nuclear elongation and streaming, pyknotic tightly packed epidermal nuclei, dark staining of epidermal nuclei, homogenization of dermal collagen, and vascular dilatation, congestion, hemorrhage and thrombosis. The study revealed that certain histological changes are helpful in differentiating electrocution mark from other types of injuries, which present themselves in various types morphologically and thus facilitate correct diagnosis during autopsy. Pyknotic and tightly packed epidermal nuclei was found characteristic of electrocution mark produced by high voltage current.

INVESTIGATION OF THE EFFECTS OF PLANT VARIETY AND SOIL SEDIMENT TO THE COASTAL ABRASION IN WEST SUMATRA

Indonesia has many islands that are suffering from beach abrasion. This phenomenon has beenoften happening and is categorized in one of the National Disasters. West Sumatra beaches with the totallength of about 600 km stretch along the west side of Sumatra Island where directly opposite to the IndianOcean. The waves from the Indian Ocean in any circumstance may cause abrasion to damage houses andpublic facilities. Factors that affect coastal abrasion include coastal geometry, wave parameters, soil sedimentand beach plantations. An investigation on the plant species and soil sediment on the West Sumatra beach hasbeen done. The effects of the last two factors on beach abrasion are then elaborated in this paper. It is foundthat some beach vegetations have shown remarkable role to reduce abrasion impact. Meanwhile, the type ofsoil sediments in which associated with physical properties showed also significant effect. From this study, itwas found that vegetation roots will protect the beaches together with the soils. This investigation alsoconcludes that coastal endemic plants in the West Sumatra need to be explored as a mitigation action toreduce the abrasion impact.

Design and Development of Denim Fabrics with Improved Strength and Impact Abrasion Resistance for Motorcyclist Clothing

This study aims to design and develop denim fabrics with enhanced mechanical and impact abrasion resistance performance using different materials, yarn types and fabric constructions. It was aimed to reach the standard impact abrasion resistance requirements of motorcycle protective clothing for Level 1 in high impact areas of the body (zones 1 and 2), such as hip and knee areas. The existence of cotton/Cordura® yarn in warp and T400 polyester yarn in the weft and the use of higher yarn densities increased the performance in tensile strength and impact abrasion resistance, compared to a classical cotton denim fabric. The use of coarser yarns and fabrics with a double weave construction increased impact abrasion resistance compared to single layer cloths. The double and backed cloth samples developed with cotton/Cordura® and Kevlar®/polyester yarns in their construction showed impact abrasion resistance times over 4 s and reached the “EN 13595-2:2002 Level 1 abrasion resistance” standard requirement.

An electrophoretic coating using a nanosilica modified polyacrylate resin

Polyacrylate resins were prepared by a copolymerization of acrylates and methacrylates, in the presence (or absence) of a reactive nanosilica (RN), and polyacrylate resins were also modified by a half-blocked toluene diisocyanate (TDI). The RN, was prepared by a sol-gel process using tetraethyl orthosilicate (TEOS) and functionalized with 3-(trimethoxysilyl) propyl methacrylate (MPS). The RN was determined to have an average particle diameter of around 10 nm. The resin was thus transformed into an emulsion and deposited on steel plate using an electrophoretic coating process. The deposited films were further cured in an oven, where the half-blocked TDI crosslinked to form networks. The presence of nanosilica in the deposited film enhances physical properties, such as abrasion resistance, impact resistance, and thermal stability.

Material failure detection for intelligent process control in CFRP machining

In machining operations like drilling or milling of carbon fiber reinforced composites (CFRP), error influences on the workpiece material affect the productivity and reliability of part manufacturing. Process errors and material failures such as delamination, fiber pull-out and fringes are inacceptable regarding the part quality and safety requirements in many applications. In order to avoid critical damages of the workpiece material, an appropriate tool design incorporating the macro and micro geometry of the cutting edges as well as sophisticated coatings is necessary. In addition, the selection of adjusted process parameters, such as feed velocity and spindle speed, is essential for an optimization of the performance and stability of machining. Due to the abrasive impact of the fibers, severe tool wear occurs during machining which also has an effect on the formation of process errors and material defects. In order to enable reliable machining operations and stable part manufacturing, process monitoring approaches are investigated. The aim of monitoring is to detect critical process conditions as soon as they occur and to initiate appropriate measures for the avoidance of workpiece damages. These measures often entail an interruption of the running process and an exchange of the used tool. A process control, on the other hand, means an adjustment of the process parameters during machining that allows the continuation of the operation with the currently applied tool but without a damage of the workpiece. The fundamental question with respect to process control strategies is, how to adjust the process parameters adequately. Besides information about the actual process conditions which can be gathered from the monitoring signals, a knowledge-base including the interrelations between process parameters, tool wear and process error effects has to be available.In this paper, experimental investigations regarding the dependencies between tool state, process quality criteria and process parameters are presented and discussed. Furthermore, several process monitoring strategies are analyzed and assessed with respect to the implementation of process control strategies. In addition, the concept of an intelligent process control system incorporating the above mentioned dependencies is introduced.

Economic Adaptation Strategies of Coastal Communities Affected by Environmental Degradation (Study Case: Sayung Sub-district, Demak)

Sayung sub-district experienced the most severe abrasion impact in some villages. Abrasion not only drowns Rejosari and Tambaksari dukuh, but also shifts the pattern of life or social culture of coastal communities who choose no longer rely on the fishery sector ponds. The research used descriptive qualitative method that is research type which use description of field condition in writing. The type of questionnaire used is a questionnaire with open-closed questions (open-closed questions). The result is that 74% of Bedono local people feel that the environmental condition has worsened since the increasing of abrasion. The income level of Bedono local people as much as 60% of its citizens experienced a decrease in income level due to abrasion. Although, with the worse conditions caused by severe abrasion that damage the environment, local people of Sayung sub-district have economic adaptation strategies to improve their financial aspect based on tourism development. On the other hand, the potential of Sayung Beach and surrounding areas to become Community Based Tourism is considered very unique.