Papers by Keyword: Wear Test

Abstract: In power transmission systems, gears are the most essential parts. Gear failure would happen at any regular working cycles and it must be avoided with special care. The mode of failure suggests that optimum material and suitable post processing has to be done. Industry demands more efficient, reliable, and lightweight gears. Hence more efficient, reliable, and lightweight gears must be developed and manufactured. Eventhough lot of investment is being done on research and implementing new technologies while manufacturing gears, stills some failures is arised. Many physical factors, including the inappropriate materials composition, may induce gear failure. In this paper, some typical diverse materials, like nylon 6 and glass fibers are mixed with various volume proportions to enhance wear resistance and improve gear’s life. Polymer gears developed in this study offer more superior life than pure nylon gears. All the prepared specimen samples are tested to a variety of studies including Tensile, Compression, Flexural, Impact, TGA and Wear tests. Depreciation is not reducing low, however. 90% nylon 6 + 10 % Glass fiber to 10% nylon 6+ 90Glass fiber 10 % Nylon 6 has mixed for investigation. Based on the investigation, 70% of Nylon 6 + 30% glass fiber has high strength, low wear, and high wear resistance.

Abstract: There is a significant improvement in specific strength and wear resistance of metal matrix composites (MMCs) in comparison to unreinforced alloys. Low-density reinforcements such as SiC havethe advantageof beingrelatively inexpensive and readily available abundantly and is cost-effective among the several uneven dispersoids used. Meagre work is carried out on processing of Al2219-SiC MMCs which is the originality of current work. The Al2219 matrix alloy in the current study was reinforced with different weight percentages of SiC (3%, 5%, and 7%), and it was produced by the stir casting process. Its microstructure and physical properties were examined, and it was then compared to the alloy as-cast. A study of SiC reinforced Al2219 MMC characterization and stir casting technology is presented in this paper to illustrate its salient features.

Abstract: This study deals with the hardening of titanium surface by carburising of CP Ti Gr 2 substrate by using laser sintering process. The objective of this project is to harden the surface to improve surface wear resistance of titanium. In this study graphite powder is used as source of Carbon. Carbon from graphite reacts with titanium and TiC layer of 109 micron was measured on the titanium surface. The microstructure and phase analysis results show that presence of only TiC phase on the surface of the titanium substrate. TiC grains are nearly 5 times finer than titanium substrate grains. Grain refinement of TiC phase all over the surface of the substrate resulted in increase in hardness and development of significant wear resistance surface in titanium substrate. Hardness of TiC layer was found to be 2191Hv which is nearly ten times higher than the substrate titanium. Wear test results of pin and disc type shows negligible wear rate as compared to CP Ti substrate. TiC grains are nearly 5 times finer than titanium substrate grains.

Abstract: The paper contains the results of surface modification on the properties of the pure titanium Grade II, obtained by the SLM procedure. In the paper, the analysis of the results of physicochemical properties, such as pitting corrosion test and contact angle measurements and Surface Free Energy calculated were performed. Additionally, the microscopic observation with microchemical analysis, surface topography analysis using Atomic Force Microscopy, surface roughness measurements and wear test were performed too. The studies were carried out on three groups of samples in an initial state (1) (after mechanical treatment - mechanical grinding and polishing) and after surface modification by PVD method using CrN layer (2) and TiN layer (3). Based on the obtained results it can be concluded that the samples with TiN layer were characterized by the optimum properties.

Abstract: Aluminium alloys are having lightweight, high strength, good corrosive resistance, and toughness. In this paper, A7075/B4C/SiC Hybrid Composites fabricated with different wt. % of reinforcement materials by using stir and squeeze casting process. The SEM Microstructure have shown that uniform distribution of reinforcement particles in the A7075 matrix reinforced with 1 % wt. % B4C and 1 % wt. % SiC. The Mechanical properties of A7075/B4C/SiC Hybrid Composites were studied Composite A7075/B4C/SiC reinforced with 1 % wt. B4C and 1 % wt. SiC has shown more compressive and tensile strength compared to base alloy. The compressive strength of the composite increased 39.73 % and the tensile strength is increased 36.67 % compared to base alloy. From the dry sliding wear studies, the Composite with 1 B4C wt. % have shown less weight loss and coefficient of friction at all conditions due to the uniform distribution of the micro-particles within the matrix surfaces. Worn surface morphology has revealed that severe wear of A7075 base alloy became mild wear by preparing composite with 1 % wt. SiC, 0.5 wt. % B4C and then mild wear became less wear with shallow grooves by increasing reinforcement weight percentage of B4C from 0.5 to 1.

Abstract: The selection of the relative movement mode between the friction pairs in simulated friction and wear tests is a crucial factor for the characterization and evaluation of metallic material properties. In this study, two kinds of commonly used metal materials (stainless steel 0Cr18Ni9 and aluminum alloy 2A12) were applied for the simulated friction and wear tests with four different modes of relative motion, including unidirectional, reciprocating, circular and multi-directional cross-shear. The corresponding surface topography and statistical parameters such as surface roughness Ra were obtained via OLYMPUS ultra-depth microscope. Based on the fractal theory, fractal dimension D was calculated to characterize the surface topography and the results indicate that, the fractal dimension D of the unidirectional and multi-directional cross-shear simulated friction and wear tests is the minimum and maximum respectively, which reflects that the fractal dimension D is able to characterize the complexity of the surface morphology. The fractal dimension D may be related to the intrinsic physical properties of metal materials, such as hardness and toughness, which needs to be further studied.

Abstract: The importance of medium carbon steels as engineering materials is reflected by the fact that out of the vast majority of engineering grade ferrous alloys available and used in the market today, a large proportion of them are from the family of medium carbon steels. Typically medium carbon steels have a carbon range of 0.25 to 0.65% by weight, and a manganese content ranging from 0.060 to 1.65% by weight. Medium carbon steels are more resistive to cutting, welding and forming as compared to low carbon steels. From the last two decades a number of research scholars reported the use of veritiy of heat treatments to tailor the properties of medium carbon steels. Spheroidising is the novel industrial heat treatment employed to improve formability and machinability of medium/high carbon low alloy steels. This exclusive study covers procedure, the effects and possible outcomes of various heat treatments on medium carbon steels. The austenite phase present in steel above the critical temperature has the tendency to form variety of non equilibrium phases depending upon the degree of supercooling or cooling rates. The near spherical or curved shaped carbides records least resistance for machining because the blunt cornered shapes are having least free energy with minimum internal stresses. There is a need to formulate the heat treatment process to tailor the characteristics in line with the application. The age old normalizing treatment provides more nucleation sites required for so that finer spheroids are dispersed in the matrix to improve toughness with balanced bulk hardness related properties to improve machinability. In line with requirements, the heat treatment cycle to balance mechanical and microstructural properties of AISI 1040 structural steel is designed. It is observed that lower spheroidizing temperature gives finer spheroids, more in number with better improvement in toughness whereas higher Spheroidization temperature reduces hardness values with lesser spheroid density, accordingly reduces strength and impact resistance. The balanced improvement in properties may be incorporated for metal removal operations to improve productivity and tool life.

Abstract: Soft and hard FeCrNiSi alloy coatings were obtained on 30CrMo alloy steel surface by laser cladding. The phase constitution, microstructure, frictional wear behavior and corrosion resistance of the composite coating were analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), three-dimensional non-contact surface mapping, friction and wear testing machine and electrochemical workstation, separately. XRD analysis showed that the cladding layer was mainly composed of Fe-based alloy composition, accompanied by a small amount of cobalt nickel alloy. There were massive protrusions in the interface of the soft sample, and the coating was regularly dendritic. Hard sample coating lines were cluttered, and there was no bulk deposition. Under the same wear condition, the soft coating exhibited serious abrasive wear, while the hard coating had slight abrasive wear behavior. The polarization curves in 3%NaCl solution revealed that the self-corrosion potential of the soft coating was positive shifted more than that the hard coating. The soft coating has better corrosion resistance than the hard coating.

Abstract: The high temperature phase austenite in steel has the property to transform into a variety of room temperature phases like coarse pearlite, bainite & martensite depending upon the cooling cycle. The machinability and toughness depend upon the shape and distribution of pro eutectoid harder phases. The spherical or oval shapes give lesser resistance for machining process. So it is required to design the heat treatment to tailor the property as required by the application. In this view, it is proposed to study the mechanical and micro structural properties of EN47 steel undergoing Spheroidization. The aim of this work is to test the hardness, toughness and wear property of the steel in spheroidised condition. Hardening treatment improves hardness of the material, a marginal decrease in hardness value with improved ductility is observed in tempering. Hardening and longer duration tempering show better wear resistance compared to other heat treatments. Both mild and severe wear regions are observed. Generally mild wear region is observed above five hours of continuous running of the specimen. Micro structural analysis shows the existence of pearlitic structure in as bought & normalized specimen, lath martensitic structure in hardened specimen.

Abstract: While axial piston pump is the core component of hydraulic system, its service life and reliability depend much on the selection of materials, friction pairs and process parameters. To identify these factors, wear condition of friction pair is conducted by using MWF-10 wear rig. Based on ANOVA of Taguchi Method,the influences of surface roughness and hardness on wear loss and friction coefficient are compared. In addition, the results show that the optimal friction pair and surface roughness of hard specimens have influence mostly on the wear loss and the friction coefficient.