Papers by Keyword: Abrasion

Abstract: Twin Wire Arc spraying (TWAS) is a well-established method to deposit metallic coatings to protect mechanical components from wear and corrosion. In this work were used coatings that can be divided into two groups: FeCr-based ones and NiCr-based ones. The microstructure, and mechanical properties such as hardness, adhesion, abrasion and erosion resistance were evaluated on these coatings. The wear behavior of the coatings was investigated by Solid Particle Erosion resistance test and by Dry sand/Rubber wheel abrasion test. The aim of this work is to study the wear mechanism by SEM observation of worn tracks.

Abstract: Comfort, protection and similar characteristics, which have become imperative for the production of sportswear materials, constantly encourage the textile industry and researchers to search for new innovative solutions. Recently, there are three main areas that scientists focus on - comfort, functionality and aesthetic appeal of sportswear. For the purpose of this research, a set of novel yarns is selected and used to design knitted materials intended for the production of functional sportswear. In this paper the changes in the material properties due to the use of different novel yarn compositions are observed. Regarding the material properties, the mass loss due to the material abrasion, and water vapour transfer rate were measured and analysed. The results of the investigation indicated that the material with the lowest mass, thickness and densities (both horizontal and vertical) exhibit the lowest decrease of mass due to abrasion. The highest decrease of mass is confirmed for the most compact material composed of viscose, polyester standard and elastane. It was further confirmed that the highest water vapour transfer rate exhibits the material that has the lowest density.

Abstract: Abrasive water jet machining is a process that removes material using sand and water. This versatile process uses a high-pressure water jet loaded with abrasive particles of mineral origin. It allows the machining of all materials and is particularly suitable for machining or stripping applications on hard metal sheets. Due to a local action, the abrasive water jet limits heating and deformation. During machining, the removal of material occurs abrasion and erosion [1]. The identification of the respective importance of this abrasion and this erosion conditions the precision of the modeling of the machined depth. In this study, these mechanisms are presented and characterized for machining on 6mm thickness TiAl6V titanium alloys sheets with or without inclination of the jet. It is possible to model an elementary passage and it allows predicting the pocket bottom profile obtained after a succession of passages. During machining, two mechanisms appear. Abrasion occurs when machining an elementary pass. Erosion will characterize the effect of repetition of passages. The analysis of the machined profiles makes it possible to characterize the influence of the abrasion mechanism and abrasion mechanism. The variation of the coefficients associated with these mechanisms can be characterized as a function of the angle of inclination of the jet.Keywords: Abrasive water jet machining, Material removal mechanism, Abrasion, Erosion, Titanium alloy, Abrasive particles

Abstract: This paper is focused on magnetorheological (MR) dampers and their critical parts in terms of damper`s durability, which seems to be a piston-rod seal. An option to reduce the wear is to choose the proper material for that purpose. The wear measurements were conducted in an accelerated and simplified mode in a modified pin-on-flat (cylinder-on-flat) configuration, which was supposed to be more suitable for laboratory testing than original configurations. Suitable commercial materials for seals, like PTFE, NBR, SBR and polyurethanes, were tested and compared in commercial MR fluid MRF-132DG by LORD Corporation. It turned out that material H-PU95FDA had had the biggest wear resistance from all tested materials and therefore it was the most suitable material for durable seals, while PTFE seals are expected to be suitable in non-durable applications with low frictional forces.

Abstract: Aiming to evaluate the resistance of High Performance Concrete (HPC) against the abrasion erosion due to the continual impact of water and water borne materials, six HPC mixtures reinforced with different fibers and fiber combinations were prepared and tested experimentally in this study. All mixtures share the same contents of all materials, while the types and combinations of fibers used were different among the mixtures. All mixtures included a total of 2.5% volumetric content of fibers. The mixture S6 included pure 6 mm micro-steel fiber (S6), S15 mixture included pure 15 mm micro-steel fiber (S15), while the S6-S15 mixture included 1.25% of each of S6 and S15. S6-PP and S15-PP included 2.0% of S6 or S15, respectively, in combination with 0.5% of polypropylene fiber (PP), while the sixth mixture included 1.0% S6, 1.0% S15 and 0.5% PP. The impact abrasion test was conducted on 200×200 mm plat targets with 50 mm thickness that were fixed perpendicular to a water jet with a high speed of 20 m/s. The results revealed that all HPC mixtures exhibited much higher abrasion resistance than normal concrete. The results also showed that the S15 mixture was the one with highest abrasion resistance with an abrasion loss of only approximately 20 grams after 12 hours testing.

Abstract: Abrasion measurement of surface of specific concrete elements is presented in this paper. This article is focus on determination of wear resistance and strength of concrete floor. This concrete contains silicon carbide binder and part of it is recycled origin. This material are high on Mohr hardness scale and are they are suitable for use in indoor and outdoor areas with the heaviest traffic loads. From the results, follows that the even small differences in mixture (using new and recycled binder) has impact on the mechanical parameters. However, it is possible design mixture with recycled binder and reach characteristic of concrete, which are almost similar to the normal concrete.

Abstract: An experimental program was directed in this study to evaluate the abrasion resistance of reactive powder concrete (RPC) under direct normal impact of water jet. Abrasion and compressive strength specimens were cast from six RPC mixtures using different single and hybrid distributions of 6 mm-length and 15 mm-length micros-steel fibers and 18 mm-length polypropylene fiber. Fixed mix proportions were used for the six RPC mixtures and with fixed total volumetric fiber content of 2.5%. In addition to the RPC mixtures, a normal concrete mixture was prepared for comparison purposes. All specimens were cured in the same conditions and tested at an age of 28 days. The test results showed that abrasion weight losses increase with time at rates that are independent of fiber type and fiber distribution. The results also showed that all RPC mixtures exhibited significantly lower abrasion losses than normal concrete. The lowest percentage abrasion weight losses were recorded for the mixture with pure 15 mm micro-steel, where after 12 testing hours, it was 0.41% of the total weight before testing. On the other hand, the mixture with pure 6 mm micro-steel fiber exhibited the highest percentage abrasion weight loss (0.98%) among the six RPC mixtures. Another conclusion is that the inclusion of polypropylene fiber to compose hybrid fiber distribution with micro-steel fiber led mostly to lower abrasion losses.

Abstract: Abrasion is the physical wear of a surface due to cyclically recurring dynamic forces and shifts. Therefore, abrasion resistance can be defined as the ability of a surface to resist wear due to friction. The paper deals with the issue of the resistance of concrete surface layers to the effects of abrasion. The research focused on monitoring the influence of different types of aggregate on increasing the abrasion resistance of concrete surfaces. Concrete surfaces with three different types of aggregate were tested: amphibolite, granodiorite and psammite. The concrete class was C35/45. Abrasion was tested using the Böhme method. The highest abrasion resistance after 28 days of maturation was found in concrete surfaces with amphibolite aggregate.

Abstract: Wear is one of the foremost issues faced in manufacturing industries that reduces the lifestyles of machine elements and will increase the running costs. Therefore, hardfacing is extensively employed by industry professionals to minimise the wear of moving components. In this research work, a nickel based alloy recognized as Hastelloy C-276 was strengthened on stainless steel (316L) substrate via the usage of Gas Metal Arc Welding (GMAW) technique. The coating thickness used to be assorted was from 1 to 3 mm on the substrate. The optical microstructure of the interface revealed the defect-free fusion between hardface and substrate metals. Microhardness (Hv) and three-body abrasive put on test have proven that the hardfaced alloy metal posses higher hardness and effective wear resistance. The worn surface morphologies have been found using SEM in order to perceive the involved wear mechanisms.

Abstract: How to extend your lifetime before you start using it or more often during use is a matter for every investor. In this paper, we will try to assess whether the use of protective coatings on concrete floors has a positive effect on the service life. The referee in our case will be the highly abrasive test method Böhme, which determines abrasion resistance. For comparison, we chose coatings based on sodium silicate solution, ie water glass. The market for these protective coatings is very diverse, so we have chosen to select products of renowned and unknown producers in different price ranges to cover the widest possible market.