Sialon工程陶瓷抗摩擦磨损性能的研究

本文采用实验的方法，分析了工程陶瓷的摩擦磨损机理，并以此对陶瓷材料在不同载荷及滑动速度下的磨损特性进行了分析和研究。     

结构陶瓷的摩擦磨损

本文综述了目前国内外结构陶瓷摩擦磨损的研究现状,重点评述了外部因素（主要包括摩擦方式、环境、负载、滑动速度、温度及时间等）对陶瓷摩擦磨损的影响,内部因素（主要有硬度、强度、韧性、弹性模量、粒径、气孔率、晶界相等）与磨损量的关系及搽恋裂磨损过程的各种模型,并就目前结构陶瓷摩擦磨损研究中的一些问题和热点进行了简要的讨论。     

对几种陶瓷材料抗磨性的浅探

初步探讨了在摩擦磨损系统中３种陶瓷材料──氧化锆增韧氧化铝（ＺＴＡ）、部分稳定氧化锆（ＰＳＺ）、氧化锆增韧莫来石（ＺＴＭ）和高铬铸铁材料的耐磨性。通过比较，陶瓷材料比金属材料具有更强的抗摩擦磨损能力，而且在这３种陶瓷材料中，ＺＴＡ的耐磨性最好，其磨损机理为塑性切削机制和脆性剥离机制。     

碳化硅陶瓷摩擦化学磨损机理及磨损图的研究

研究了碳化硅陶瓷自对偶摩擦在空气中从室温到1200℃的摩擦磨损特性、磨损图和摩擦化学。其摩擦学特性与实验温度和载荷密切相关，磨损呈现3种模式：即其比磨损率分别随温度的升高呈现基本不变、增加和减少的规律。在此基础上用磨损图描述了磨损特性和试验温度及载荷等摩擦环境参数的关系。碳化硅陶瓷自对偶摩擦的高温摩擦化学反应产物－无定形SiO2平滑薄膜层的形成与破坏是影响磨损的主要原因。     

氧化硅陶瓷高温摩擦学性能

本文研究热压氮化硅陶瓷与３Ｃｒ２Ｗ８Ｖ钢组成的销－盘摩擦副，在空气中非润滑条件下，４００￣８００℃不同载荷（４９￣３４３Ｎ）的摩擦磨损性能；测定了磨擦系数的Ｓｉ３Ｎ４销的磨损因子；通过对Ｓｉ３Ｎ４磨损面的ＳＥＭ形貌观察、Ｘ射线相结构分析，探讨了陶瓷销的磨损机理。     

Sialon陶瓷干摩擦磨损特性初探

本文研究了销-盘式sialon陶瓷摩擦副的干摩擦磨损随环境温度变化的特性。实验测定了摩擦副在空气中、室温到600℃环境温度下的摩擦系数和磨损因子。用SEM、TEM和X射线衍射技术观察和分析了磨损前后摩擦副的表面形貌、截面特征、磨屑的形状和磨屑及磨痕的相组成。本文试图揭示该材料的摩擦磨损随环境温度变化的特性并初步探讨磨损机理。实验结果表明:sialon陶瓷的主要磨损机理是断裂层离。     

SG—4工程陶瓷加工表面抗磨损性能的研究

本文采用摩擦磨损试验，从的微观结构入手，研究了ＳＧ－４工程陶瓷的磨损同理，并在上基础上讨论了该材料在室温条件下，滑动摩擦时的磨损特征。     

无机颗粒填充复合材料摩擦磨损性能研究进展

综述无机粒子填充聚合物复合材料的摩擦磨损性能，从磨损类形、机理、填料的摩擦学作用、摩擦副及工况条件(滑动速度、载荷、温度)的影响等几个方面分析了目前填充改性复合材料摩擦磨损性能的研究进展情况。试验证实，填料与聚合物、聚合物与摩擦副、填料与摩擦副均可能发生化学反应。     

干摩擦条件下Ti（CN）—Al2O3复合陶瓷与金属摩擦副的摩擦学特性研究

为了模拟陶瓷刀具的磨损过程，对干摩擦条件下Ｔｉ（ＣＮ）－Ａｌ２Ｏ３复合陶瓷与纯铝、纯铁和不锈钢３种金属的摩擦、磨损特性进行了研究。结果表明：随着速度或载荷的增加，摩擦副中金属与陶瓷的磨损量均很快增大。金属的磨损量比对摩的陶瓷的磨损量大得多。３种金属中，铝的磨损量最大，铁和不锈钢的磨损量较小。与铝与摩的陶瓷的磨损量小是由于：（１）铝的硬度小，易剪切，不会对陶瓷造成较大损伤；（２）在摩擦过程中，金属和     

表面强化镀层对高速轴承腔密封端面变形及摩擦磨损影响分析

为了揭示表面强化镀层有效改善高速轴承腔油润滑机械密封的耐磨性和稳定性机制，本文采用数值分析与试验相结合的方法，对端面镀Cr强化机械密封展开端面变形及摩擦磨损性能分析。通过热力耦合数值模拟分析了不同厚度Cr镀层摩擦副对端面温升、变形的影响，使用摩擦磨损试验机研究了相应摩擦副对摩擦系数和磨损量的影响，采用高速密封样机测试了端面温升、密封效果，探究了强化镀层密封端面摩擦磨损强化机理。结果表明：热力耦合作用下高速密封端面产生发散型变形，端面磨损以磨粒磨损为主，端面外侧出现局部黏着磨损；对比无镀层密封端面，Cr镀层端面变形小，温升低，更容易形成稳定的摩擦转移膜；适当增加Cr强化层厚度有利于降低端面温升，提高密封稳定性，高速轻载工况下较优镀层厚度约为0.15mm。本文研究结果可以为高速轴承腔油润滑机械密封材料选配和结构优化提供借鉴。     

Tribological behavior of carbon nanotube and polytetrafluoroethylene filled polyimide composites under different lubricated conditions

The friction and wear behavior of polyimide (PI) composites reinforced with carbon nanotube (CNT) and polytetrafluoroethylene (PTFE) were comparatively evaluated under dry sliding, water‐, oil‐ or alkali‐lubricated condition. The wear mechanisms of the composites were also discussed. Results indicate that, when comparison with the dry friction situation, PI‐based composites results lower friction coefficients and wear rates under oil‐ or alkali‐lubricated condition. The lowest wear rate of the CNT/PTFE/PI composite is recorded as 1.2 × 10⁻⁶ mm³/Nm during the composite sliding in alkali, which is only about 40% of the value sliding under dry friction condition. The worn surface of neat PI under dry sliding is characterized by severe adhesive wear, whereas abrasive wear is the main character for CNT/PTFE/PI composites. The worn surfaces of CNT/PTFE/PI composites sliding in oil or alkali lubricated condition are smoother than those under dry or water condition. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Mechanical properties of polydicyclopentadiene/graphite nanosheet composites prepared by reaction injection moulding

Abstract

Polydicyclopentadiene (PDCPD)/expanded graphite nanosheets treated with silane coupling agent (TEG) composites were prepared by simulating reaction injection moulding. Studies on the mechanical and tribological properties of the composites were carried out. The results showed that TEG of low content had an effect on reinforcing the PDCPD matrix. The incorporation of TEG in PDCPD greatly decreased wear rates and slightly increased friction coefficients under both dry sliding and oil lubricated conditions. The SEM images of the worn surface revealed their wear mechanisms. Unfilled PDCPD was characterised by spalling, with adhesive wear being the major wear form. Polydicyclopentadiene composites were characterised by plastic deformation, fatigue microcracking, spalling and ploughing effect in dry sliding. The wear forms for PDCPD composites under oil lubricated condition were also complicated, and several wear forms such as adhesive, abrasive and fatigue wears co-existed.     

水润滑下纳米三氧化二铝/端异氰酸酯基聚丁二烯液体橡胶-环氧树脂复合材料的摩擦性能

研究了纳米Al2O3/端异氰酸酯基聚丁二烯液体橡胶-环氧树脂(ETPB)复合材料在水润滑条件下的摩擦性能,并用扫描电子显微镜表征了复合材料的磨损表面形貌,探讨了磨损机理。结果表明,在水润滑条件下,纳米Al2O3/ETPB复合材料的磨损率和摩擦系数低于ETPB;载荷和滑动速率的变化对纳米Al2O3/ETPB复合材料的磨损率、摩擦系数及磨损表面形貌影响不大,复合材料的磨损表面均未产生裂纹;ETPB的磨损机理为疲劳磨损,纳米AlO/ETPB复合材料的磨损机理为机械抛光磨损。     

芳纶浆粕增强丁腈橡胶复合材料的摩擦磨损性能

利用开炼机制备了丁腈橡胶(NBR)/芳纶浆粕(PPTA-pulp)复合材料。研究了在干摩擦和水润滑条件下,纤维含量、摩擦时间以及载荷对NBR/PPTA-pulp复合材料摩擦磨损性能的影响,并分析了磨损机理。结果表明,芳纶浆粕的加入能够很好地改善复合材料的力学性能和摩擦磨损性能,在相同条件下,当纤维质量分数为20%时,复合材料的综合性能最佳;在干摩擦条件下,随着摩擦时间延长,复合材料的摩擦系数下降,磨耗量增大;随着载荷增加,摩擦系数和磨耗量增大;水润滑条件下,复合材料的摩擦系数和磨耗量较干摩擦大幅度降低且比较稳定,时间和载荷对其影响很小;干摩擦时,复合材料的磨损机理主要为磨粒磨损和疲劳磨损;水润滑时,主要为轻微磨粒磨损。     

Softening and melting mechanisms of polyamides interfering with sliding stability under adhesive conditions

The thermal stability of polymers is a main issue when used as friction elements under dry sliding. Cast polyamide grades processed with either natrium or magnesium catalysors are slid on a small-scale and a large-scale test configuration to reveal the effect of softening or degradation on the sliding stability and to investigate possibilities for extrapolation of friction and wear rates between both testing scales. The combination of softening and afterwards transition into the glassy state is detrimental for the sliding stability of natrium catalysed polyamides, characterised by heavy noise during sliding. A transfer film formed under continuous softening also provides high friction. Melting during initial sliding is necessary for stabilisation in both friction and wear, and eventual softening of a molten film near the end of the test then not deteriorates the sliding stability. Softening of magnesium catalysed polyamides is favourable for the formation of a coherent transfer film resulting in more stable sliding than natrium catalysed polyamides. The differences in softening mechanisms of both polyamide grades is correlated to structural changes investigated by thermal analysis and Raman spectroscopy: the γ crystalline structure prevails in magnesium catalysed samples and the α crystalline structure is predominant in natrium catalysed samples. For internal oil lubricated polyamides, a time dependent degradation of the polyamide bulk deteriorates the supply of internal oil lubricant to the sliding interface, resulting in high friction and wear under overload conditions. As the degradation mechanisms during sliding are strongly correlated to the test set-up, extrapolation is only possible for friction in a limited application range, while wear rates cannot be extrapolated.     

干摩擦及水润滑下氧化锆-氧化铝层状复合陶瓷的摩擦学行为

研究了氧化锆氧化铝三层结构层状复合陶瓷在干摩擦和水润滑下的摩擦学性能和磨损机制，并比较了氧化锆-氧化铝单层陶瓷在相同条件下的摩擦学性能。结果表明：相同条件下，层状陶瓷的摩擦系数和磨损率均低于单层陶瓷，根本原因在于层状陶瓷表面的压应力导致的韧性提高和磨损表面剪切应力的降低。水润滑可以有效地降低复合陶瓷的摩擦磨损，主要原因是由于水引起主导磨损机制发生变化，由干摩擦时的磨粒磨损和粘着磨损转变为摩擦化学磨损和疲劳磨损。     

超细羟基硅酸镁粉体在磨损后钢表面的自修复特性(英文)

使用AMSLER摩擦磨损试验机进行摩擦磨损试验,研究超细羟基硅酸镁粉体作为润滑油添加剂在磨损后摩擦副表面的自修复特性。使用扫描电子显微镜、能谱仪和X射线光电子能谱分析了2种润滑油润滑下磨损后的45#钢环的表面形貌和化学组成。结果显示:经50h纯润滑油润滑后在45#钢表面出现了大量的划痕,而之后经50h含添加剂润滑油润滑后这些划痕被自修复膜所覆盖。这层自修复膜主要由Fe,O,Si,C和Mg构成,这表明粉体添加剂在摩擦磨损过程中可以向磨损的金属表面发生转移。自修复膜的形成原理是这些粉体可以吸附到钢的磨损后新鲜表面,之后在接触表面的剪切应力下铺展于磨损后金属表面。这层自修复薄膜可以明显提高金属摩擦副的抗磨损性能。     

半芳香族聚酰胺PA6T及其PTFE复合材料的摩擦磨损性能研究

对3种不同共聚结构的聚对苯二甲酰己二胺（PA6T）树脂——聚对苯二甲酰己二胺/己内酰胺（1132）、聚对苯二甲酰己二胺/己二酰己二胺（M21）和聚对苯二甲酰己二胺/己二酰己二胺（1252）以及其聚四氟乙烯（PTFE）复合材料在干摩擦条件下的摩擦磨损性能进行了研究,并使用扫描电子显微镜（SEM）对试样的磨损面进行了分析。结果表明,1252的摩擦磨损性能最好,M21次之,1132最差;PTFE的加入提高了3种树脂的摩擦磨损性能,其中对1252的摩擦磨损性能改善最大,当PTFE含量为30份（质量份,下同）时,其摩擦因数和磨损率分别降低到了0.16和1.00×10^-6;磨损机理方面,1132的磨损方式主要表现为粘着磨损和疲劳磨损,而M21和1252的主要磨损方式表现为磨粒磨损;随着PTFE含量的增加,复合材料的主要磨损方式均转变为粘着磨损。     

Tribological behavior of short‐fiber‐reinforced polyimide composites under dry‐sliding and water‐lubricated conditions

Polyimide composites reinforced with short‐cut fibers such as carbon, glass, and quartz fibers were fabricated by the polymerization of monomer reactants process. The mechanical properties of the composites with different fiber contents were evaluated. The friction and wear properties of the polyimide and its composites were investigated under dry‐sliding and water‐lubricated conditions. The results indicated that the short‐carbon‐fiber‐reinforced polyimide composites had better tensile and flexural strengths and improved tribological properties in comparison with glass‐fiber‐ and quartz‐fiber‐reinforced polyimide composites. The incorporation of short carbon fibers into the polyimide contributed to decreases in the friction coefficient and wear rate under both dry and water‐lubricated conditions and especially under water lubrication because of the boundary lubrication effect of water. The polyimide and its composites were characterized by plastic deformation, microcracking, and spalling under both dry and water‐lubricated conditions, which were significantly abated under the water‐lubricated condition. The glass and quartz fibers were easily abraded and broken; the broken fibers transferred to the mating metal surface and increased the surface roughness of mating stainless steel, which led to the wear rate increasing for the glass‐fiber‐ and quartz‐fiber‐reinforced polyimide composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Wear resistance of stabilized zirconias

The wear resistance of stabilized zirconias was investigated on both a pin-on-disk machine and a Dangoumeau apparatus under dry and lubricated (water) conditions. Under the experimental conditions (80 N load and 12 mm/s speed) the wear mechanism can be described as initial plastic deformation and then grain pull-out. The role of the third-body in the interface of friction has been demonstrated with asymmetric couples where one of the antagonists is made of alumina. If for pure friction it is not easy to differentiate the magnesia partially stabilized zirconias (MgPSZ) from the yttria tetragonal zirconia poly crystal (YTZP), after shock tests we can conclude that the YTZP have a better wear behaviour than the MgPSZ, especially in the case of attrition applications.