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1.
The sliding friction and wear behaviour of unreinforced polyetheretherketone (PEEK) matrix and its unidirectional continuous and two-dimensional woven graphite fibre-reinforced composites were investigated. The operating wear mechanisms, as evinced by scanning electron microscopy of the worn surfaces, and the coefficients of friction and the wear rates changed considerably with the fibre reinforcement form and orientation. Sliding wear rates, on account of their extreme sensitivity to the microstructure of the interacting surfaces at the sliding interface, were found to be a function of not only the surface roughness, but also of the sliding time. Complex interactions arising due to the effects of the testing parameters such as fibre orientation, sliding velocity, contact pressure and interface temperature were characterized for the neat matrix and the two composite systems. The wear rates of the two-dimensional woven composites were almost an order of magnitude lower than those of the unidirectional fibre composite or the unreinforced matrix.  相似文献   

2.
飞灰颗粒增强铝基复合材料的摩擦与磨损特性   总被引:4,自引:0,他引:4       下载免费PDF全文
对挤压铸造制成的飞灰颗粒增强ZL109复合材料在不同条件下的摩擦磨损特性进行了研究。研究结果表明:在较低载荷和较低滑动速度下,该复合材料的耐磨性明显优越于基体铝合金,摩擦系数也稳定地低于基体铝合金,并且随飞灰含量的增加复合材料的耐磨性有所提高;在较高载荷和较高滑动速度下,同基体铝合金相比复合材料耐磨性的改善程度有所降低,但复合材料的摩擦系数仍可以保持较低的水平。这是由于随着载荷和滑动速度的变化,复合材料的磨损机制发生了转化。本文对该过程中的磨损机制的转化进行了初步分析。  相似文献   

3.
Application of short fiber reinforced thermoplastic materials are limited to functionally less important components due to heterogeneous characteristics of material and incomplete understanding of failure mechanisms involved. Reinforcement not only affects mechanical and electrical properties but also the failure mechanisms. Gears used in power/motion transmission may fail in many ways. This paper discusses the various types of failures exhibited by unreinforced and fiber reinforced Nylon 66 gears. Injection molded unreinforced, glass reinforced and carbon reinforced Nylon 66 spur gears were tested in a power absorption type gear test rig. Failed gears were observed under optical and scanning electron microscope to understand the damage mechanism. Different types of failures such as gear tooth wear, cracking at the tooth surface, tooth root cracking and severe tooth shape deformation were observed. Material compositions and applied torque decides the type of failure mechanism. Low interfacial strength between fibers and matrix in the reinforced gears causes fiber pullout. Reinforced gears exhibited longer life compared with the unreinforced gears due to superior mechanical strength and thermal resistance.  相似文献   

4.
Jute fibre reinforced polyester composites were developed and characterized for friction and sliding wear properties. Effect of fibre orientation and applied load on tribological behaviour of jute fibre reinforced polyester composites were determined. It is found that wear resistance was maximum in TT sample, where fibres were normal to sliding direction. Wear rate under sliding mode follows this trend; WTT < WLT <WLL LL sample showed higher capability to sustain the load whereas lowest wear resistance found in this case. The coefficient of friction found highest for TT sample and lowest for LT sample. The coefficient of friction decreased with increase of applied load. Worn surfaces were analysed and discussed with the help of SEM.  相似文献   

5.
The AZ91 metal matrix composites (MMCs) reinforced with 5, 10 and 15 wt.% TiC particulates are fabricated by TiCp–Al master alloy process combined with mechanical stirring. The effects of TiC particulate content, applied load and wearing time on the sliding wear behaviors of the composites were investigated using MM-200 wear testing apparatus. The results show that the wear resistance and friction coefficient of the composites increased and decreased with increase of the TiC particulate content, respectively. The wear volume loss and friction coefficient of the reinforced composites as well as the unreinforced AZ91 matrix alloy increased with increase of applied load or wearing time, but the increase rates of the reinforced composites in two performance is lower than those of the unreinforced AZ91 matrix alloy. Furthermore, the sliding wear behavior of the composites and the unreinforced AZ91 matrix alloy is characterized by ploughing, adhesion and oxidation abrasion.  相似文献   

6.
The dry sliding wear behavior of Ti2AlC reinforced AZ91 magnesium composites was investigated at sliding velocity of 0.5 m/s under loads of 10, 20, 40 and 80 N using pin-on-disk configuration against a Cr15 steel disc. Wear rates and friction coefficients were registered during wear tests. Worn tracks and wear debris were examined by scanning electron microscopy, energy dispersive X-ray spectrometry and transmission electron microscopy in order to obtain the wear mechanisms of the studied materials. The main mechanisms were characterized as the magnesium matrix oxidation and self-lubrication of Ti2AlC MAX phase. In all conditions, the composites exhibit superior wear resistance and self-lubricated ability than the AZ91 Mg alloy. In addition, the anisotropic mechanisms in tribological properties of textured Ti2AlC-Mg composites were confirmed and discussed.  相似文献   

7.
The friction and wear behavior of carbon nanotube reinforced polyamide 6 (PA6/CNT) composites under dry sliding and water lubricated condition was comparatively investigated using a pin-on-disc wear tester at different normal loads. The morphologies of the worn surfaces and counterfaces of the composites were also observed with scanning electron microscopy (SEM). The results showed that CNTs could improve the wear resistance and reduce the friction coefficient of PA6 considerably under both sliding conditions, due to the effective reinforcing and self-lubricating effects of CNTs on the PA6 matrix. The composites exhibited lower friction coefficient and higher wear rate under water lubricated condition than under dry sliding. Although the cooling and boundary lubrication effect of the water contributed to reduce the friction coefficient of the composites, the adsorbed water lowered the strength of the composites and also inhibited the formation of transfer layers on the counterfaces resulting in less wear resistance. With the increasing normal loads, the friction coefficient of the composites increased under the dry sliding and decreased under the water lubricated condition, owing to inconsistent influences of shear strength and real contact areas. The specific wear rate of the composites increased under both sliding conditions.  相似文献   

8.
The tribological properties of carbon fiber reinforced polyimide (PI) composites with different MoS2 containing sliding against GCr15 steel were comparatively evaluated on an M-2000 model ring-on-block test rig. The wear mechanisms were also comparatively discussed, based on scanning electron microscopic examination of the worn surface of the PI composites and the transfer film formed on the counterpart. It was found that small incorporation of MoS2 was harmful to the improvement of friction and wear behaviors of carbon fiber reinforced PI composites. However, it was found that the increasing filler of MoS2 significantly improved the wear resistance and decreased the friction coefficient of carbon fiber reinforced PI composites. It was also found that the tribological properties of MoS2 and short carbon fiber reinforced PI composites were closely related with the sliding condition such as sliding rate and applied load.  相似文献   

9.
The effects of various reinforcements (boron carbide ‐silicon carbide‐alumina) with constant volume fraction (20 %) on the abrasive wear properties of AA6061 matrix composites produced with hot pressing process were investigated. The wear tests were carried out using a pin‐on‐disk wear tester by sliding at sliding speeds of 1.2 m/s against silicon carbide paper. Applied normal loads have 5, 10 and 15 N magnitude at room temperature. The wear morphologies of the worn surfaces were analyzed using a scanning electron microscope in order to examine the wear characteristics and to investigate the wear mechanisms. The effects of reinforcement type on the wear behavior of AA6061 matrix composites were observed. Results exhibited that the optimum wear resistance obtained with the boron carbide reinforced composite parts. All reinforced samples showed better wear resistance compared to as‐received samples in all the studied conditions. Scanning electron microscope characterization showed that test specimens have complex combination of wear mechanisms on the worn surface.  相似文献   

10.
《Composites》1993,24(4):347-353
The influence of three thermosetting matrix resins — epoxy, polyester and poly(vinylbutyral)-modified phenolic — on the sliding wear of glass woven roving reinforced polymer composites under dry conditions has been investigated. Amongst the three composites, glass/phenolic composites exhibit the highest mechanical properties whereas the highest wear resistance (minimum specific wear rate) is offered by glass/epoxy composites. The critical velocity, at which the specific wear attains a minimum value, is higher for glass/polyester composite than for the other two composites. The lowest coefficient of friction has been observed in glass/phenolic composites at all sliding velocities.  相似文献   

11.
Effect of nanoclay reinforcement on tensile and tribo behaviour of Nylon 6   总被引:2,自引:0,他引:2  
Polymer nanocomposites are particle-filled polymers in which at least one dimension of the dispersed particles is in the nanometer range. Dispersing nanosize particles in a polymer matrix induces superior mechanical properties compared to traditional macro fillers. Nanolevel reinforcement also affects the tribological properties and needs to be clearly understood before using in practical applications. Friction and wear characteristics of Nylon 6 nanocomposites under dry sliding conditions are reported in this paper. Nylon 6 with 5% organoclay was prepared by melt intercalation technique. The tensile behaviour is evaluated according to ASTM standards. A pin-on-disc type tribometer is used for evaluating the friction and wear behaviour. It is found that the Nylon 6 nanocomposites have superior tribological properties than unfilled polymer. Formation of uniform tenacious transfer layer by Nylon 6 nanocomposite on the counterface contributes to the reduction in coefficient of friction and specific wear rate. Nylon Nancomposites exhibited high wear resistance compared with the neat Nylon.  相似文献   

12.
以注塑成型法制备MoS2和碳纤维混杂增强尼龙1010复合材料,采用MM-200型磨损试验机考察复合材料摩擦磨损性能。研究结果表明:在干摩擦条件下,MoS2和碳纤维混杂可显著改善尼龙复合材料摩擦学性能,较小载荷下复合材料磨损以轻微磨粒磨损和疲劳磨损为主,较高载荷下复合材料则以热疲劳断裂剥落磨损为主。摩擦过程中MoS2和对偶铁发生摩擦化学反应,生成和对偶底材具有较强结合能力的硫化亚铁和硫酸铁等,同时部分被氧化生成MoO3。  相似文献   

13.
Hybrid aluminum metal matrix composites reinforced with silicon carbide (SiC) and graphite (Gr) are extensively used due to high strength and wear resistance. Friction behavior of such hybrid composites is quite vital in deciding the optimal combination of SiC and Gr. The sliding friction response of stir cast hybrid aluminum composites reinforced with equal weight fraction of SiC and Gr particulates of 2.5%, 5%, 7.5% and 10% reinforcement is investigated. The influence of % reinforcement, load, sliding speed and sliding distance on friction coefficient is studied using pin-on-disk equipment with tests based on design of experiments. Hardness of the composites decreases with increase in % reinforcement. Friction coefficient is influenced by sliding speed as well as load and its average value is around 0.269. But, % reinforcement and sliding distance do not affect the friction coefficient.  相似文献   

14.
The effect of fibre orientation on the dry sliding wear of continuous B(SiC) fibre reinforced aluminium alloy composites was investigated using a pin-on-disc wear testing machine. The metal-matrix composites (MMC) samples were tested in the normal (N), parallel (P) and antiparallel (AP) orientations sliding against a steel counter disc at a fixed speed of 1 m s–1 under loads of from 12 to 60 N.The results showed that for the matrix alloy and MMCs, the average wear increased linearly with load. Wear of the MMCs was insensitive to fibre content but for composites with fibre contents at or above the minimum of 16 vol% used for this work, the wear rate was about 18% of that of the unreinforced matrix. Fibre orientation had a minor effect on wear rate; the N orientation gave the lowest wear rate with the AP orientation slightly higher and the P orientation significantly higher.The average coefficients of friction of the MMCs in N and AP orientations decreased linearly with increased wear rate and non-linearly with increased load, but the P orientation was insensitive to either variable.It was concluded from these results and a metallographic examination that the mechanism of wear of MMCs was essentially oxidative wear of the matrix. The hard fibres modified this to slightly different degrees depending on their orientation relative to the wear surface and sliding direction.  相似文献   

15.
三维网络SiC对铝合金干摩擦磨损性能的影响   总被引:6,自引:0,他引:6  
用销-盘式高温摩擦磨损实验机研究了LF3铝合金及三维网络SiC(体积分数分别为10%、20%、30%)增强LF3铝基复合材料的干摩擦磨损性能,测量了复合材料及基体合金在室温和高温(25-300℃)条件下的摩擦系数和磨损率,用扫描电镜(SEM)观察其磨损表面,研究了三维网络SiC对铝合金磨损机制的影响.结果表明:复合材料的干摩擦磨损性能远优于基体合金(LF3),而且随着温度的升高,复合材料的抗磨损性能明显提高.三维网络SiC在磨损表面形成硬的微凸体起承载作用,同时其独特的结构制约基体合金的塑性变形和高温软化,并保护在磨损表面形成的氧化膜.在相同实验条件下,复合材料的摩擦系数、磨损率随着增强体的体积分数的增加而降低.复合材料的摩擦系数在滑行过程中的稳定性明显高于基体合金.  相似文献   

16.
利用树脂传递模塑(RTM)工艺制备了三维编织炭纤维/环氧(C3D/EP)复合材料.采用MM-200型摩擦磨损试验机研究了该材料润滑条件下的摩擦磨损性能,探讨了载荷及滑动速度等外界因素的影响;并采用XL30 ESEM电子显微镜观察磨损表面形貌,分析了其磨损机理.结果表明,润滑条件下复合材料的摩擦磨损性能远优于干摩擦,且磨合期较短;随着载荷的增加,复合材料的摩擦系数和比磨损率降低,但滑动速度对摩擦磨损性能的影响很小;润滑条件下的磨损机理主要是磨粒磨损.  相似文献   

17.
《Composites Part A》2002,33(10):1453-1459
In ceramic matrix composites, it is now well known that the cyclic fatigue effects are due to a decrease of the stress transfer capability of the fibres that bridge the matrix cracks, because of some wear induced by the seesaw displacements at the interfaces. Therefore, a better knowledge of the cyclic fatigue effects needs a deeper understanding of the microscale mechanisms operating during the friction between fibre and matrix. This is the main subject of the present paper which deals with single filament model composites submitted to push-out tests at room temperature under dry friction condition. Emphasis is placed here on the roughness of the slipping surfaces in relation with thermal misfit, and with sliding velocity.  相似文献   

18.
Ultra‐high‐molecular‐weight polyethylene (UHMWPE) reinforced with carbon fibre (CF) underwent an enhancement of heat and wear resistant with the addition of polyphenyl ester (POB) and graphite, respectively. The effect of graphite content on the tribological properties of the composites was studied. The wear surface was examined using scanning electron microscope (SEM). The results of the sliding wear tests showed that with graphite loading, wear resistance increased and the coefficient of friction was much more stable. In addition, graphite improved the tribological properties of the composite. Hardness, impact strengths and thermal stability of the composites were enhanced. With increased load, the wear rate of the ultra‐high‐molecular‐weight polyethylene+carbon fibre+polyphenyl ester+10 % graphite composite tended to increase, whereas the coefficient of friction decreased. The adherence and plastic deformation were dominant wear mechanisms for the ultra‐high‐molecular‐weight polyethylene+carbon fibre+polyphenyl ester+graphite composites. The formation of a thin and uniform transfer film was observed.  相似文献   

19.
通过摩擦实验及X射线光电子能谱分析(ESCA)研究了碳纤维增强聚醚醚酮滑动时形成的转移膜的摩擦性能,结果表明,与纯聚醚醚酮和聚醚醚酮+聚四氟乙烯相比,碳纤维增强聚醚醚酮材料形成的转移膜薄,连续性均匀性好,因此其磨擦学性能好转移膜的成分沿其垂直于膜面的方向变化,表明此膜中存在着石墨和聚四氯乙稀的优先转移提出滑动磨擦转移膜的形成的粘着转移机制  相似文献   

20.
In the present work, a comparison of the tribological properties of Nylon6-Al-Al2O3 and ABS parts fabricated using the fused deposition modelling (FDM) method is made. Under dry sliding conditions at room temperature, the sliding wear behaviour of FDM-built parts with three different proportions of Al and Al2O3 was investigated. Loads of 5, 10, 15 and 20 were applied at a sliding velocity of 1.36 m/s for durations of 5 and 10 minutes. The results show that all FDM-built Nylon6-Al-Al2O3 components have better wear resistance as compared to their FDM-built ABS counterparts. Further, the influences of filler materials on various wear mechanisms such as adhesion, abrasion, etc. are identified. It was also observed that the composite materials prepared with different proportions are more wear resistant, having less friction coefficients and friction force than the commercially used ABS material for FDM components.  相似文献   

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