Papers by Keyword: Wear Rate

Abstract: Nowadays, 316L stainless steel implant materials exhibit a promising position in the field of biomaterials application, especially in medical due to their higher strength compared to other ceramic base materials. Therefore, in this work, the production of 316L implant materials and examination of the mechanical characteristics were carried out. Powder Metallurgy process has been chosen to produce the implant materials due to its high advantages in demonstrating the high mechanical properties of the green sample. 316L stainless steel with zinc streate powder of three different compositions, i.e., the first of 99% 316L stainless steel and 1% zinc stearate, the second of 97% 316L stainless steel and 3% zinc streate, and the third of 95% 316L stainless steel and 5% zinc streate, were cold pressed individually at 600 MPa pressure using UTM and sintered the green samples at 1120 °C for 1 hour and 30 minutes. Sintering temperature and time were the same for all the specimens. We investigated the mechanical behaviour of 316L stainless steel implant materials of different compositions at the same temperature for the same duration of time. After that, the mechanical properties and densification of this material were investigated.

Abstract: The influence of fiber length and treated chemically on wear properties by using jute fibers reinforcing in polymer-matrix composites (PMC) has been considered. From the results, it was found that The wear rate decreasing with increasing load from (78.6 -70.35)%, (65.6-59.16)% and (72.9-67.7)% for (5,10,15) KN load respectively that decreasing due to disintegrating the sample's surface under increasing loads. also, The wear rate decreases with increasing load from (78.6 -70.35) gm/mm (65.6-59.16)gm/mm and (72.9-67.7) gm/mm for (5,10,15) KN load respectively that decreasing due to disintegrating the sample's surface under increasing loads. also,The rate of wear decreases with an increase in the length of the fibers by (65%), due to the effect of fiber length that causes difficulty in separating between fibers from the polymeric material, which means that the material is resistant to collapse and also in the presence of a chemical in the processing, which causes a strong bond and good adhesion between the reinforcing material and the material The basis resulting from pitting caused by chemical treatment.

Abstract: In this study, polymer composites were manufactured with epoxy-based resin and wastes as a mineral additive. The wastes including a high content of silica (Silica fume, glass and fly ash) powder were used as fillers for an epoxy adhesive to improve its wear resistance properties. They were supplemented to mixes in various ratios via substituting the resin from 0 to 20% by weight. Tests of wear rate and hardness were conducted upon all-polymer composites at all fillers ratios. Results indicated that the epoxy hardness increased with increasing the filler addition. Consequently, the addition of wastes that include silica raised the wear resistance of polymer composites; nevertheless, it caused the composites harder materials. The wear rate decreased with increasing the silica fume, glass, and fly ash addition. In the case of fly ash addition, the minimum wear rate was at 15%, and after this percentage, the wear rate increased. However, in the case of glass addition, the minimum wear rate was at 10%, and after this percentage, the wear rate increased.

Abstract: Aluminium alloy has gained importance in the automotive and aerospace industry as it is easily available and easy in manufacturing. In the recent years, materials science has gained huge importance in the field of composites. In the field of composites metal matrix composite is playing a lead role in industrial applications. The unique combinations of properties provided by aluminum and its alloys make aluminum one of the most versatile, economical and attractive metallic materials. To enhance the properties of aluminum, it has been reinforced with alumina, silicon carbide, graphene and others. In this study, A357 aluminum has been strengthened by using different weight percent of alumina as reinforcement. Percentage of alumina used are 4%, 8% and 12% to enhance the mechanical and tribological property of A357.The fabricated samples were studied to understand the performance of the composite for mechanical and tribological characters. It was observed that the composites showed superior properties compared to the base material. Statistical analysis i.e. regression analysis has been carried out for hardness and tensile strength of alumina reinforced aluminum composite.

Abstract: The present work aims at the study of the dry disc pion contact and the complex phenomenon of the wear as well as the sliding friction of our sample elaborated by a hot isotactic compression and the pion. This study consists in determining the coefficient of friction and the influence of the tribological parameters on this phenomenon as well as determining the loss of mass and the wear rate of study sample. In order to enhance the assurance of the validity of the results of tribological study of Ni-Cr-B-Si-C-W alloy in laboratories and compare that to the tribological conditions in reality and industries. This work presents the results of the new approach to compares the wear behavior of the sample between a theoretical study (tribometer)and another in service (a test bench) that reproduces approximately the same conditions as the tribometer (normal load, sliding speed and distance traveled) by measuring the loss of mass and wear rate.

Abstract: Tungsten Carbide (WC) hard coating is widely used to coat the surface of the steel tools which provide tribological properties. In this paper, 0.25 wt% & 0.35 wt% of Carbon Nanotubes (CNT) were mixed with tungsten carbide (WC) powders as the feedstock powders. Method of solution dispersion in ethanol media using an ultrasonic device was used for coating the surface of WC powders with CNT powder. The mixed powders were then used as the feedstock powder to coat onto the surface of tool steel using the flame spraying process. The coated surface microstructures were observed under a scanning electron microscope (SEM), x-ray diffraction (XRD), and the energy dispersive spectroscopy (EDS) was used for the phase characterization and identification. The wear rate of coated steels was determined using the Ogoshi machine, and the Vickers hardness method used to measure their microhardness. The effects of CNT on the microstructure of the coated material and the surface mechanical properties were investigated. The results showed that the mixture powder preparation using an ultrasonic method in SDS solution and the ball-milling process was suitable to disperse the CNT on the surface of WC feed powders due to produce an adequate relationship between CNT' and WC powders increasing the surface mechanical properties of coatings. The wear resistance of the coated material produce using the mixture of WC powder with 0.35 wt% CNT increased around 50% higher than the WC coated steel without CNT addition. Also, the hardness of coating reinforced CNT increased significantly compared with the hardness of WC coated and the steel substrates. Microhardness value from the base metal to the WC-CNT coated steel increased from 550 HV to 1717 HV and also the wear rate from the base metal to the WC-CNT coated steel decreased from 0.86 mm³/min to 0.017 mm³/min. These results indicate that CNT is an excellent alternative to improve the surface mechanical properties of WC coatings.

Abstract: The paper deals with hard cutters of drill bits for drilling rocks. The research on geometry of hard alloy and steel cutters of bits that work either under conditions of shockless loads was carried out in this work. The rationale of tungsten carbide and cobalt composition according to their hardness and robustness is provided. Different alloys were suggested to be used for tools working either under conditions of shockless loads or under shock loads for drilling rocks of high hardness. The rock deformation process was identified to occur by cutting and shearing forces. The highest influence on the cutting process is exerted by the acuity angle and back rake angle. Peculiarities of work of cutters with positive, negative and neutral back rake angles were determined as part of the main research. The dependence of penetration depth on the back rake angle of the cutter was obtained. Indicators of wearing identified in the research are including the type and properties of interacting surfaces characterized by the roughness of cutting bit surface, the hardness of materials in contact zone, friction mode that depends on unit pressure, movement rate, the nature of load application, and the rate of interaction of working parts of bit.

Abstract: Ni-Al-Ti system is one of the intermetallic systems that attract wide interest for high-temperature application. In this work, combustion synthesis was used to produce intermetallic materials prepared by Ni/Al with varied Ti content using 3%, 10%, 20%, and 30%. The reactant mixtures were compressed in a steel die to form compacted pellets. The ignition of the combustion process was conducted using an arch flame. Sequential tests of SEM, EDS, and XRD were conducted to characterize the microstructure of the synthesized products, whereas the mechanical properties of the product were measured using a Vickers microhardness test and wear test. The result shows that the phases formed in the product were dominated by Ni-Al and Ti-Ni systems. An increase in the Ti content from 3% to 20% increases the hardness. The formation of several intermetallic phases was responsible for the harder products. An increase of Ti content decreases the wear rate. This work shows that the content of 10% Ti can be used to achieve the optimized properties of hardness and wear resistance.

Abstract: This work is devoted to research of the structural-phase condition and changes in the mechano-tribological properties of 0.3C-1Cr-1Mn-1Si-Fe structural steel after plasma electrolytic cementation. Using metallographic and X-ray analysis, mechano-tribological tests, it was found that 0.3C-1Cr-1Mn-1Si-Fe steel in the initial state belongs to the ferritic-pearlitic class, which contains ~ 65% of pearlite grain and 35% of ferrite grain. When samples of 30HGSA steel are saturated with carbon, a modified surface layer with a thickness of 25μm is formed on the surface of the studied samples, including α-Fe ferrite, cementite Fe₃C, iron Fe₃C₂ carbide and an alloying element. It was established that the intensity of wear of the samples after modifying decreased by 2 times, and the surface microhardness after cementation increased 3 times, depending on the original sample.

Abstract: The paper is focused on the elaboration of some sintered steels with Cr concentration between (1-2 %) wt., carbon as graphite with a concentration of 0,4% wt. and Fe for the balance. The samples were die pressed at 600 MPa and sintered at 1150 °C in argon atmosphere. The samples were studied from the point of view of wear behavior against three types of counter balls, alumina (Al₂O₃), steel (100Cr6) and stainless steel 440C. The results shows that the lowest value for the friction coefficient was attained for the steel with 1,5% Cr. Also, microhardness tests were performed and reveal that the highest value was equal to 229 HV_05.