Wear Rate

The present work describes the surface improvement and biocompatibility of TiAl 24 Nb 10 intermetallic alloy using rf plasma nitriding. The nitriding process was carried out at different plasma power from 400 W to 650 W where the other plasma conditions were fixed. Grazing incidence X-ray diffractometry (GIXRD), Auger electron spectroscopy (AES), tribometer and a nanohardness tester were employed to characterize the nitrided layer. Further potentiodynamic polarization method was used to describe the corrosion behavior of the un-nitrided and nitrided alloy. It has been found that the Vickers hardness (HV) and corrosion resistance values of the nitrided layers increase with increasing plasma power while the wear rates of the nitrided layers reduce by two orders of magnitude as compared to those of the un-nitrided layer. This improvement in surface properties of the intermetallic alloy is due to formation of a thin modified layer which is composed of titanium nitride in the alloy surface. Moreover, all modified layers were tested for their sustainability as a biocompatible material. Concerning the application area of biocompatibility, the present treated alloy show good surface properties especially for the nitrided alloy at low plasma power of 400 W. #

This technical paper describes the abrasive wear rate of as-cast and heat-treated Al (6061) alloy reinforced with 9% by weight of SiC particulate and 0, 1, 3 and 5% by weight of E-glass fibre subjected to different ageing durations. The liquid melt technique route is used to produce the castings. Castings were machined to the ASTM standards and T6 heat-treatment process is carried out. All the specimens were artificially aged to different durations like 1, 3, 5 and 7 h at a temperature of 175 • C. Wear tests were performed on various composites in both the heat-treated and as-cast conditions using pin-on-disc machine. In each test the wear rates of the hybrid composites were found to decrease with increase in ageing durations. However, in both as-cast and heat-treated hybrid composites, the wear rate increased with increase in the sliding distance.

In railway systems, certain atmospheric conditions-mainly related to temperature and relative humidity-lead to the creation of iron oxides which can affect the coefficient of friction between the wheel and the rail. This can result in increased wear of the rail, reducing its service life and thus increasing replacement costs. Pin-on-disc tests were conducted in a climate chamber to study the influence of environmental conditions and iron oxides on the coefficient of friction. The iron oxides generated on the surface of specimens extracted from microalloyed rail steel during wear tests were analysed using X-ray diffraction. The results show that hematite (α-Fe 2 O 3) is the predominant iron oxide among all the oxides generated on the worn surfaces. It was further noted that the oxide layer resulting from the rise in both temperature and relative humidity does not significantly affect the average coefficient of friction for each steel samples tested. High relative humidity combined with high temperature leads to the formation of α-Fe 2 O 3 , which tends to increase the coefficient of friction. However, a boundary lubrication effect is observed at higher relative humidity due to a condensed water film, which reduces the coefficient of friction and counteracts the increase of the coefficient of friction expected due to the presence of hematite.

The present work focuses on the effect of reinforcing polymer with TiO 2 and Al 2 O 3 Nano-powders on its thermal properties since they have many important thermal applications. The effect of adding such Nano-powders with different particle percentages by weight (0.5%,1%, 1.5% and 2%) to the base material have been discussed. Different samples of the resulting Nano-composite materials have been prepared according to (ISO-220077) standard. Thermal properties of such samples have been evaluated by using hot disc technique and the results have been compared with that of pure epoxy. The results show that the thermal conductivity and thermal diffusivity increase with increasing weight fraction of reinforcing materials, and it becomes higher when the epoxy was reinforced by (Al 2 O 3) rather than (TiO 2) Nano powder. Also the results indicated that maximum values of thermal conductivity and diffusivity of the Nano-composite specimen reinforced by 2% (Al 2 O 3) were (0.55W/m.K) & (0.45 mm 2 /Sec.) respectively. It has also shown that the heat capacity of the Nano-composite material decreases when the epoxy reinforced with Al 2 O 3 and TiO 2 Nano-powders with different weight fractions.

In this work application of Micro cellulose fibre in brake pad composites were successfully carried out. Micro cellulose fibres were modified with 3-aminopropyltriethoxy-silane before using in the brake pad. Four different brake pads were prepared using compression moulding process with the different ratio of micro cellulose fibre along with, phenolic resin, barium sulphate, aluminium oxide and graphite. Properties of prepared brake pads were evaluated in terms of density, water and oil soaking test, compressive strength, hardness, flame resistance, wear rate, X-ray diffraction, thermogravimetric analysis, the coefficient of friction and scanning electron microscope. Brake pad composition with 10% weight of micro cellulose fibre showed the promising result with respect to other attempted compositions and are comparable to commercial sample.

In this research the wear rate of one type of the thermosetting polymer (polyester) reinforced by ceramic particles (silica) has been investigated. A Pin-on-Disc wear testing machine of variable speed has been used. Flat against flat sliding surfaces under variable working parameters conditions have been tested. Statistical and mathematical analyses were used to the processing of the experimental data. A mathematical model was done which shows the wear rate of composite materials as a function of grain size and weight fraction. The results of flat sliding surfaces show that the wear rate of the specimens depends heavily on the working condition. It increases with the increase of the load and sliding speed. The results also show that the wear rate decreases with the increase of the weight fraction and the decrease of the grain size of the reinforcing particles. The optimum wear resistance of the reinforced polyester was at weight fraction of (20 %) and grain size of (25 m). ‫ﺍﻟﺴﻠﻴﻜﺎ‬ ‫ﺒﺩﻗﺎﺌﻕ‬ ‫ﺍﻟﻤﻘﻭﻯ‬ ‫ﺃﺴﺘﺭ‬ ‫ﻟﻠﺒﻭﻟﻲ‬ ‫ﺍﻟﺒﻠﻰ‬ ‫ﻤﻌﺩل‬ ‫ﺴﻠﻭﻙ‬ ‫ﺩﺭﺍﺴﺔ‬ (Sio 2) ‫ﺃ‬. ‫ﻡ‬. ‫ﺩ‬. ‫ﻋﻠﻴﻭﻱ‬ ‫ﻜﺎﻅﻡ‬ ‫ﺠﻭﺍﺩ‬ ‫ﺍﻟﻤﻭ‬ ‫ﻫﻨﺩﺴﺔ‬ ‫ﻗﺴﻡ‬ ‫ﺍﺩ‬ / ‫ﺍﻟﺘﻜﻨﻭﻟﻭﺠﻴﺔ‬ ‫ﺍﻟﺠﺎﻤﻌﺔ‬ ‫ﺍﻟﺨﻼﺼﺔ‬ ‫ﺒﺎﻟﺤﺭﺍﺭﺓ‬ ‫ﺍﻟﻤﺼﻠﺩﺓ‬ ‫ﺍﻟﺒﻭﻟﻴﻤﺭﺍﺕ‬ ‫ﺍﻨﻭﺍﻉ‬ ‫ﻷﺤﺩ‬ ‫ﺍﻟﺒﻠﻴﺎﻥ‬ ‫ﺴﻠﻭﻙ‬ ‫ﺩﺭﺍﺴﺔ‬ ‫ﺘﻤﺕ‬ ‫ﺍﻟﺒﺤﺙ‬ ‫ﻫﺫﺍ‬ ‫ﻓﻲ‬) ‫ﺃﺴﺘﺭ‬ ‫ﺍﻟﺒﻭﻟﻲ‬ (‫ﺴﻴﺭﺍﻤﻴﻜﻴﺔ‬ ‫ﺒﺩﻗﺎﺌﻕ‬ ‫ﺍﻟﻤﻘﻭﻯ‬) ‫ﺍﻟﺴﻠﻴﻜﺎ‬ .(‫ﺍﻟﺒﻠﻰ‬ ‫ﻗﻴﺎﺱ‬ ‫ﺠﻬﺎﺯ‬ ‫ﺍﺴﺘﺨﺩﻡ‬ ‫ﻟﻘﺩ‬) ‫ﺍﻟﻤﺴﻤﺎﺭ‬-‫ﻋﻠﻰ‬-‫ﻗﺭﺹ‬ (‫ﺍﻟﺴﺭﻉ‬ ‫ﺫﻭ‬ ‫ﺍﻟﻤﺘﻐﻴﺭﺓ‬. ‫ﻤ‬ ‫ﺴﻁﺢ‬ ‫ﻋﻠﻰ‬ ‫ﺍﻟﺩﺭﺍﺴﺔ‬ ‫ﺃﺠﺭﻴﺕ‬ ‫ﻤﺴﻁﺢ‬ ‫ﺴﻤﺎﺭ‬-‫ﻤﺨﺘﻠﻔﺔ‬ ‫ﻭﻀﺭﻭﻑ‬ ‫ﻤﻌﺎﻟﻡ‬ ‫ﺘﺤﺕ‬ ‫ﻤﺴﻁﺢ‬ ‫ﻗﺭﺹ‬ ‫ﻋﻠﻰ‬. ‫ﻭﺍﻹ‬ ‫ﺍﻟﺭﻴﺎﻀﻴﺔ‬ ‫ﺍﻟﺘﺤﻠﻴﻼﺕ‬ ‫ﺍﺴﺘﺨﺩﻤﺕ‬ ‫ﻟﻤﻌﺎﻟﺠ‬ ‫ﺤﺼﺎﺌﻴﺔ‬ ‫ﺔ‬ ‫ﺍﻟﻌﻤﻠﻴﺔ‬ ‫ﺍﻟﻘﻴﻡ‬. ‫ﻋﻼﻗﺔ‬ ‫ﻴﺒﻴﻥ‬ ‫ﺭﻴﺎﻀﻲ‬ ‫ﻤﻭﺩﻴل‬ ‫ﻋﻤل‬ ‫ﺘﻡ‬ ‫ﻟﺩﻗﺎﺌﻕ‬ ‫ﺍﻟﻭﺯﻨﻲ‬ ‫ﻭﺍﻟﻜﺴﺭ‬ ‫ﺍﻟﺤﺒﻴﺒﻲ‬ ‫ﻟﻠﺤﺠﻡ‬ ‫ﻜﺩﺍﻟﻪ‬ ‫ﺍﻟﻤﺭﻜﺒﺔ‬ ‫ﻟﻠﻤﺎﺩﺓ‬ ‫ﺍﻟﺒﻠﻰ‬ ‫ﻤﻌﺩل‬ (Sio 2). ‫ﺍﻟ‬ ‫ﻤﻌﺩل‬ ‫ﺒﺎﻥ‬ ‫ﺍﻟﻤﻨﺯﻟﻘﺔ‬ ‫ﺍﻻﺴﻁﺢ‬ ‫ﻨﺘﺎﺌﺞ‬ ‫ﺒﻴﻨﺕ‬ ‫ﺍﻟﻌﻤل‬ ‫ﻀﺭﻭﻑ‬ ‫ﻋﻠﻰ‬ ‫ﻜﺒﻴﺭﺓ‬ ‫ﺒﺼﻭﺭﺓ‬ ‫ﻴﻌﺘﻤﺩ‬ ‫ﻟﻠﻌﻴﻨﺎﺕ‬ ‫ﺒﻠﻰ‬. ‫ﺤﻴﺙ‬ ‫ﺍﻻﻨﺯﻻﻗﻴﺔ‬ ‫ﻭﺍﻟﺴﺭﻋﺔ‬ ‫ﺍﻟﻤﺴﻠﻁ‬ ‫ﺍﻟﺤﻤل‬ ‫ﺯﻴﺎﺩﺓ‬ ‫ﻤﻊ‬ ‫ﺍﻟﺒﻠﻰ‬ ‫ﻤﻌﺩل‬ ‫ﻴﺯﺩﺍﺩ‬. ‫ﺍﻟﺘﻘﻭﻴﺔ‬ ‫ﻟﻤﺎﺩﺓ‬ ‫ﺍﻟﺤﺒﻴﺒﻲ‬ ‫ﺍﻟﺤﺠﻡ‬ ‫ﻭﻨﻘﺼﺎﻥ‬ ‫ﺍﻟﻭﺯﻨﻲ‬ ‫ﺍﻟﻜﺴﺭ‬ ‫ﺯﻴﺎﺩﺓ‬ ‫ﻤﻊ‬ ‫ﻴﻘل‬ ‫ﺍﻟﺒﻠﻰ‬ ‫ﻤﻌﺩل‬ ‫ﺒﺎﻥ‬ ‫ﺍﻟﻨﺘﺎﺌﺞ‬ ‫ﺒﻴﻨﺕ‬ ‫ﻜﺫﻟﻙ‬. ‫ﺒﺩﻗﺎﺌﻕ‬ ‫ﺍﻟﻤﻘﻭﻯ‬ ‫ﺃﺴﺘﺭ‬ ‫ﻟﻠﺒﻭﻟﻲ‬ ‫ﻟﻠﺒﻠﻰ‬ ‫ﻤﻘﺎﻭﻤﺔ‬ ‫ﺃﻓﻀل‬ ‫ﻭﺍﻥ‬ (Sio 2) ‫ﻭﺯﻨﻲ‬ ‫ﻜﺴﺭ‬ ‫ﻋﻨﺩ‬ ‫ﻜﺎﻨﺕ‬ (20 %) ‫ﺤﺒﻴﺒﻲ‬ ‫ﻭﺤﺠﻡ‬ (25 m) .

Friction and wear behaviors of ball bearings made from carbon-chrome steel were experimentally simulated using a modified ball-on-disc tribometer. The test was performed over a broad range of applied loads (W), sliding velocities (v) and sliding distances (L) under gas lubricated conditions using a Taguchi method. The results found that gas blown to the sliding surfaces in air effectively reduced the coefficient of friction as compared with the air lubrication at higher applied load, sliding speed and sliding distance. In addition, a specific wear rate is constant throughout the tests under gas lubricated conditions. However, under air lubrication, the specific wear rate decreases with increasing applied load, sliding speed and sliding distance. By using the optimal design parameters, a confirmation test successfully verify the N2-gas lubrication reduced average coefficient of friction and simultaneously improved wear resistance about 24 % and 50%, respectively. This is in accordanc...

Titanium Grade 2 sample piece were subjected to wear on standard linear reciprocating tribometer machine for dry sliding condition in the constant temperature. Taguchi method were use to predict the wear rate against parameter such as Load, Frequency, and time. Signal to noise ratio and ANOVA were used study the impact of these three parameter on the wear rate. In conclusion, the major statistical factor affecting wear rate is load, followed by frequency and duration. Multiple linear regression equations are developed.

Estão em desenvolvimento novos materiais para utilização em rodas ferroviárias, isto devido ao problema de descarte relacionado com os desgastes que as rodas sofrem durante o serviço. Para entender o que ocorre com as rodas ferroviárias foram estudados nesta monografia a mecânica do contato e o desgaste em aços, verificando as várias teorias e os mecanismos que os diferenciam em suas características e proveniências. Porém infelizmente existe uma grande defasagem de pesquisas de desgastes em rodas. O objetivo geral deste trabalho é correlacionar valores de taxas de desgaste retirados da literatura, com os parâmetros utilizados nos ensaios tribológicos. Foi feito uma base de dados com resultados de diferentes aços, com estes dados, foi possível usar o método de correlação para determinar a influência de parâmetros como a carga aplicada no ensaio, a velocidade, a distância percorrida, o meio no qual é realizado o ensaio e a influencia do tratamento térmico. Correlacionando sempre uma destas variáveis com a taxa de desgaste. Concluiu-se que é necessário desenvolver um padrão para os parâmetros dos ensaios, com intuito de relacionar as variáveis com os resultados e mensurar o desempenho do material no que se refere a resistência ao desgaste.

‫د‬ . ‫داوود‬ ‫خنساء‬ ‫الشمري‬ -‫د‬ . ‫الزبيدي‬ ‫باسم‬ ‫اسيل‬ -‫الحسن‬ ‫عبد‬ ‫خالد‬ ‫اﻝﻤﻠﺨص‬ ‫درﺠﺎت‬ ‫ﻋﻨد‬ ‫اﺠﻌﺔ‬ ‫اﻝﻤر‬ ‫اء‬ ‫إﺠر‬ ‫ﺜم‬ ‫ﻴت‬ ‫ﺒﺎﻝز‬ ‫اﻝﺘﻘﺴﻴﺔ‬ ‫ﺘﺄﺜﻴر‬ ‫اﺴﺔ‬ ‫در‬ ‫إﻝﻰ‬ ‫اﻝﺒﺤث‬ ‫ﻴﻬدف‬ ‫ﻴﺔ‬ ‫ار‬ ‫ﺤر‬ C°180 ‫و‬ C ° 400 ‫ﻝﻔوﻻذ‬ ‫اﻝﺒﻠﻰ‬ ‫ﻤﻌدل‬ ‫ﻋﻠﻰ‬ Cr 6 100 . ‫اﺴﺘﺨ‬ ‫وﻗد‬ ‫ات‬ ‫وﻓﺘر‬ ‫ﻤﺨﺘﻠﻔﺔ‬ ‫أﺤﻤﺎل‬ ‫ﺘﺴﻠﻴط‬ ‫ﻋﻨد‬ ‫اﻝﺒﻠﻰ‬ ‫ﻤﻌدل‬ ‫ﻝﻘﻴﺎس‬ ‫اﻝﻘرص‬ ‫ﻋﻠﻰ‬ ‫اﻝﻤﺴﻤﺎر‬ ‫ﺘﻘﻨﻴﻪ‬ ‫دﻤت‬ ‫ﻻق‬ ‫اﻻﻨز‬ ‫ﺴرﻋﻪ‬ ‫ﺘﺜﺒﻴت‬ ‫ﻤﻊ‬ ‫ﻤﺨﺘﻠﻔﺔ‬ ‫اﻨزﻻق‬ ) 2.199m\sec ( ‫اﻝﻔوﻻذي‬ ‫اﻝﻘرص‬ ‫وﺼﻼدة‬ 45HRC . ‫ﻝﻼﻨزﻻق‬ ‫اﻝزﻤﻨﻴﺔ‬ ‫ة‬ ‫اﻝﻔﺘر‬ ‫و‬ ‫اﻝﻤﺴﻠط‬ ‫اﻝﺤﻤل‬ ‫ﻴﺎدة‬ ‫ز‬ ‫ﻤﻊ‬ ‫ﻴزداد‬ ‫اﻝﺒﻠﻰ‬ ‫ﻤﻌدل‬ ‫ان‬ ‫اﻝﻨﺘﺎﺌﺞ‬ ‫أظﻬرت‬ ‫وﻗد‬ . ‫وﻜذﻝك‬ ‫اﻝﻨﺘﺎ‬ ‫اظﻬرت‬ ‫ة‬ ‫ار‬ ‫ﺤر‬ ‫درﺠﻪ‬ ‫ﻋﻨد‬ ‫اﺠﻌﺔ‬ ‫اﻝﻤر‬ ‫و‬ ‫ﻴت‬ ‫ﺒﺎﻝز‬ ‫اﻝﻤﻘﺴﺎة‬ ‫اﻝﻌﻴﻨﻪ‬ ‫ان‬ ‫ﺌﺞ‬ C° 400 ‫ﺒﻠﻰ‬ ‫ﻤﻘﺎوﻤﻪ‬ ‫ذات‬ ‫ة‬ ‫ار‬ ‫ﺤر‬ ‫درﺠﺔ‬ ‫ﻋﻨد‬ ‫اﺠﻌﺔ‬ ‫اﻝﻤر‬ ‫و‬ ‫ﻴت‬ ‫ﺒﺎﻝز‬ ‫اﻝﻤﻘﺴﺎة‬ ‫اﻝﻌﻴﻨﺔ‬ ‫ﻤﻊ‬ ‫ﻨﺔ‬ ‫ﺒﺎﻝﻤﻘﺎر‬ ‫أﻋﻠﻰ‬ C°180 .

This article reveals the wear rate and electrical conductivity of composites made of carbon powder and waste of glass bottle with a phenolic resin matrix. The study was initiated with a carbonization of coconut shell, pulverized and filtered the carbon and waste glass bottles to reach the mesh size of  300. Both materials were mixed with a composition ratio of carbon: glass, 70%:30%; 80%:20%; and 90%:10% weight. The mixture was mixed with phenolic resin adhesive and compacted with a load of 5 US ton. Results showed, the higher the carbon content, resulting in the higher the electrical conductivity, but also showed the lighter composite. Increased content of carbon powder made lighter composite, it also made the softer composite, so that the higher wear rate. Lowest wear rate was showed by a mixture of carbon-glass composite with a composition ratio of 70:30, which was 6.86738E-06 mm 3 /Nm. Carbon powder was softer than glass powder, the highest rate was indicated by the carbon-glass composite with 90:10 composition, which was 8.67425E-06 mm 3 /Nm. A high content of carbon powder encouraged an increase electrical conductivity of the composite. Mixture of carbon-glass composite with the composition ratio of 90:10 produced electrical conductivity of 0.192 S/m. composite produced the lowest wear rate of 1.3 mg·min -1 and a maximum of 20.3 mg·min -1 [2]. Tangle of long fibers of carbon from PAN soaked in adhesive mixtures containing nano particles of TiO 2 , CaCO 3 and SiO 2 , resulting in wear rate decreased, compared to the composite of woven carbon fiber only . Polyamide carbon fiber-reinforced composites has been studied, the composite produced wear rate of 2-4 × 10 -6 mm 3 /Nm . PAN-based carbon fibers were used as reinforcement fibers in carbon-carbon composites with matrix of pitch produced wear rate of 1 to 2.5 m/s/f [5]. Wear-resistant carbon-carbon composite material was ever made of carbon powder of coal waste with coal tar pitch matrix, the hot press process, the composite produced the lowest wear rate is 0.00087 (10 -7 mm 2 /kg) . Engineering composites of carbon

In the present study, the Al2219, Al2219/ B 4 C & Al2219/B 4 C/MoS 2 hybrid composites are investigated under dry sliding wear test as for ASTM G 99-95 standard. Al 2219 base matrix reinforced with B 4 C & mixture of B 4 C and MoS 2 are fabricated using stir casting technique. By using pin on disc apparatus the test was conducted by taking parameters like sliding distance, sliding velocity and loads. The result reveals that the addition of B 4 C slightly reduces wear rate of composites, further B 4 C and MoS 2 reinforcement decreases the wear rate of the hybrid composites and increases the wear resistance of the composites. The wear rate decreases with increasing the % of MoS 2 . At a lower sliding velocity the wear rate decreases and as the sliding velocity increases the wear rate increases. As the sliding distances and load increases the wear rate drastically increases.