The Role of Microstructure in Ultralow Wear Fluoropolymer Composites

Past studies have shown that the inclusion of fillers in a polytetrafluoroethylene (PTFE) matrix can improve wear resistance by nearly four orders of magnitude. These discoveries have prompted several tribological experiments over the past decade that have highlighted the importance of particle size, tribofilm formation, filler percentage, and environment. To evaluate the effect that microstructure plays on a composite’s tribological performance, PTFE-filled polyamide-imide (PAI) composites were made and tested. To investigate the role of microstructure on the tribological performance of fluoropolymer composites, 12 composite formulations of PTFE and PAI over a range of 0 to 100 vol% PAI were tested. PTFE–PAI composite samples were slid against a stainless steel countersample using a linear reciprocating tribometer under a nominal 6.35?MPa contact pressure at 50.8?mm/s sliding speed. Of the samples tested, the 25 vol% PAI showed a remarkable mean steady-state wear rate of k?=?3?×?10^?9 mm³/Nm over an extreme distance of 360?km. A serial imaging investigation revealed that a mechanical interlocking of the two polymers occurred during the sintering process, which possibly contributed to the ultralow wear rates observed in this polymer–polymer composite.     

Influence of Concentration of Aramid Fabric on Abrasive Wear Performance of Polyethersulfone Composites

In this work, three composites of polyethersulfone (PES) containing Aramid (Kevlar 29) fabric with concentration 64, 72 and 83% (by weight) were developed by the compression molding technique. These composites were characterized for their mechanical and physical properties. The abrasive-wear performance of the composites was evaluated by abrading 1 × 1 × 1 cm³ samples against silicon carbide paper under various loads. The fabric reinforcement enhanced the abrasive-wear resistance of PES significantly (approximately 3–8 times depending on the operating conditions). It was observed that the 80% fabric composite showed the highest resistance to wear and impact along with the best tensile strength and elongation properties. Its flexural strength and ILSS value, however, were lowest. The 64% fabric composite, on the other hand, showed an exactly reverse trend among the three composites. Considering all the properties simultaneously, it was concluded that in the selected range of composites 72% fabric inclusion was the optimum for the best combination of tribological and mechanical properties. Ratner–Lancaster plots showed good linearity indicating that ultimate tensile strength and elongation to break were the prominent factors controlling the abrasive-wear behavior of the composites.     

颗粒增强铝基复合材料摩擦磨损性能研究

对颗粒增强铝基复合材料及其基体与 4 0Cr钢摩擦材料组成的摩擦副的摩擦磨损特性进行了对比试验研究 ,并采用SEM对颗粒增强铝基复合材料及其基体磨损表面进行了观察 ,探讨了其磨损机理。试验表明 :复合材料具有较稳定的摩擦系数、低的磨损率 ;复合材料的主要磨损形式是磨粒磨损 ,基体材料的主要磨损形式是粘着磨损。     

不同类型吸气消声器的性能对比与试验验证

分别对单连通直接、双连通直接、单连通半直接和双连通半直接4种冰箱压缩机吸气消声器进行了数值模拟,并对比分析了其流动性能和声学性能,结果表明:双连通吸气消声器流动性能较好,而单连通吸气消声器声学性能占优。同时,对上述4种冰箱压缩机吸气消声器进行了性能试验,进一步验证了计算分析的正确性。     

工程耐磨构件表面织构及摩擦学性能研究

表面织构是利用特定的加工方法在构件的摩擦表面加工出一定尺寸和排列的微小阵列,可有效改善表面润滑状态,降低摩擦系数,减少磨损量和表面温升。分析了不同工程耐磨构件表面织构的类型和加工方法以及表面织构对构件表面摩擦学性能的影响,提出了工程耐磨构件表面织构研究的方向。     

短玻纤填充PTFE复合材料磨损性能研究

用机械共混、冷压成型和烧结的方法制备了不同质量分数(10％～40％)的短玻纤填充PTFE复合材料样品。用MM-200型磨损试验机评价了不同样品在于摩擦定载荷条件下的磨损性能；用扫描电子显微镜(SEM)对试样的磨损表面进行了观察分析。结果表明：在所采用的实验条件下，随短玻纤含量的增加，抗磨损性能先增大后减小，在含量为30％取得最佳抗磨损性能。     

碳纤维增强尼龙1010复合材料的摩擦磨损性能及磨损机理研究

以注塑成型法制备了尼龙1010及碳纤维(CF)增强尼龙1010复合材料,研究了CF含量和载荷对材料摩擦学性能和磨损机制的影响。结果表明,CF的加入可显著改善尼龙的摩擦学性能,以体积分数为20％的CF增强尼龙1010复合材料的耐磨性能最好。较低的CF含量下复合材料磨损表面主要受到对偶钢环上微凸峰的切削和犁沟作用,较高载荷时发生了热疲劳剥层磨损;随着CF含量增加,复合材料表面在较高载荷时产生明显疲劳断裂,并使对偶钢环产生较剧烈磨损。     

填料种类对聚苯酯基复合材料摩擦学性能的影响

在聚苯酯(Ekonol)中分别添加不同种类的填料,制备出一系列性能不同的Ekonol基复合材料,研究了填料的形态、性质对Ekonol复合材料摩擦磨损性能的影响,分析了磨损面、对磨面转移膜形貌,并探讨了摩擦磨损机制。结果表明,在填料的填充量相同时,层状固体润滑剂聚四氟乙烯(PTFE),由于从本质上改善了非熔融Ekonol的内部粘结,且协助形成较为连续、平滑的转移膜,对Ekonol摩擦学性能的改善最为明显;其次为纤维状填料。相比于尺寸细微的六钛酸钾晶须,粗大的玻璃纤维(GF)或碳纤维(CF)之间相互交错,对Ekonol起到了较好的承载骨架作用,更为有效提高Ekonol的摩擦学性能。GF比CF与Ekonol之间的亲和性较好,对应于GF/Ekonol复合材料的摩擦学性能优于CF/Ekonol复合材料;纳米颗粒填料对Ekonol有着弥散增强作用,但对Ekonol摩擦学性能的改善效果最差。     

Adhesive Wear Performance of T-OPRP and UT-OPRP Composites

In the current work, the effects of treating the oil palm fibres on the tribological performance of polyester composite were studied against polished stainless steel counterface using Block-on-Ring (BOR) technique under dry contact condition. Wear and friction characteristics of treated and untreated oil palm fibre reinforced polyester (T-OPRP and UT-OPRP) composites were evaluated at different sliding distances (0.85–5 km), sliding velocities (1.7–3.9 m/s) and applied loads (30–100 N). SEM observations were performed on the worn surfaces of the composites to examine the damage features. Specific wear rate (Ws), friction coefficient and interface temperature results were presented against the operating parameters. The results revealed that test parameters significantly influenced the wear performance of the composites. Both treated and untreated oil palm fibres enhanced the wear and frictional performance of polyester composites. T-OPRP showed less Ws by about 11% compared to UT-OPRP. This was due to the better interfacial adhesion offered by the treated fibres. The SEM observation made on UT-OPRP worn surface showed debonding and bending of fibres, and fragmentation and deformation on the resinous regions. Meanwhile, T-OPRP composite showed less damages compared to UT-OPRP, where no sign of fibres debonding was observed.     

SiC颗粒增强铝基复合材料的摩擦磨损机制研究

SiC颗粒增强铝基复合材料是一种性能优异的高速摩擦材料,作为刹车材料必将在陆上运输领域得到广泛应用。但SiC颗粒增强铝基复合材料的摩擦磨损性能强烈地依赖于实验条件和制备工艺。综述了各种因素对SiC颗粒增强铝基复合材料摩擦磨损性能的影响,总结了SiC颗粒增强铝基复合材料摩擦磨损机制,并指出了SiC颗粒增强铝基复合材料需进一步深入研究的问题及新的研究方向。     

Effect of Hardness Ratio on the Wear Performance and Subsurface Evolution of Ni3Al Matrix Composites

A favorable hardness ratio (H_disk/H_pin = H_d/H_p) could lead to a transition to mild wear during sliding contact. To determine a more appropriate H_d/H_p value for the sliding wear, the dry sliding pin-on-disk wear tests of Ni₃Al matrix composites (NMCs) with multilayer graphene (MLG) are undertaken at H_d/H_p values of 0.99, 0.83, 0.42, and 0.35 at sliding speeds of 0.1, 0.3, 0.5, and 0.7 m/s. It is found that the tribological properties of NMCs are strongly affected by the various hardness ratios. At 0.1 m/s, the friction coefficient decreases with a decrease in H_d/H_p value. The low friction coefficient is 0.14 and the wear rate is 0.9 × 10^?5 mm³ N^?1m^?1 under the ceramic counterpart with H_d/H_p of 0.35. At 0.7 m/s, the tribological properties show the opposite trend with a decrease in H_d/H_p. At an H_d/H_p of 0.35, the smooth compact layer on the worn surface could decrease the friction at 0.1 m/s, and the improved hardness in the subsurface by strain hardening would play an important role in the improvement of wear resistance. Under the metal counterpart with H_d/H_p of 0.99, plastic deformation only occurs on the contact surface and the MLG could suppress further shear deformation in the subsurface, leading to a low wear rate (2.4 × 10^?5 mm³ N^?1m^?1) and friction coefficient (0.15) at 0.7 m/s.     

切削铝基复合材料时的刀具磨损及影响因素

通过采用4种不同种类的刀具车削非连续增强的铝基复合材料（SiCw／2024、SiCp／2024）,借助扫描电子显微镜（SEM）检测刀具磨损后的磨损形貌,用工具显微镜测量刀具后刀面的最大磨损值,分析不同切削工况下的刀具磨损。实验结果表明,磨损主要发生在刀具的后刀面,磨损机理为磨料磨损。前刀面上同时存在着磨料磨损和粘结磨损,但都不严重,没有形成月牙洼。刀具的磨损程度与刀具材料、切削用量、复合材料的增强相体积分数及尺寸等因素直接相关。     

浸锑石墨摩擦磨损特性研究

为使石墨产品能够应用于高温及重载条件下且能表现出良好的的耐磨性和自润滑性,使用机械加压工艺将熔融锑浸入石墨坯料气孔中制得浸锑石墨复合材料,并对浸渍前后样品的微观结构、摩擦磨损性能进行了研究,评价了浸锑石墨浸渍后磨损量及润滑性能的变化。结果表明,浸锑后磨损量减少96.6%,摩擦因数降低了45%,证明浸锑后石墨材料的摩擦磨损性能有所提高。     

机械零件磨损仿真与概率寿命估算

基于离散数学理论和计算机技术,用数值仿真方法,建立通用数值仿真模型。提出磨损概率寿命概念,利用Monte Carlo法,以斜齿圆柱齿轮摩擦副磨损状态为研究对象,通过算例实现对斜齿圆柱齿轮机构磨损失效概率寿命分布的计算,解决了零件磨损概率寿命的预测问题,所建立的磨损仿真方法和模型具有良好的工程应用前景。     

矿渣微粉填充树脂基复合材料力学性能和摩擦学性能研究

为了充分利用废弃材料研发绿色制动片,在树脂基复合材料中加入不同颗粒度的矿渣微粉作为无机填料,用热压成型的方法配制试样,并对试样的力学性能和摩擦磨损性能进行试验。研究结果表明：在复合材料中加入矿渣微粉作为无机填料,摩擦系数高于未掺样且更稳定,试样摩擦系数随掺量增加而增大。增加矿渣微粉后复合材料的磨损率均有明显降低,200目掺量为30％的试样具有较好的综合性能。两种粒径试样的硬度均高于未掺试样,冲击强度略有下降,仍高于标准较多。磨损形式由未掺样的严重的粘着磨损转变为有掺样轻微的磨粒磨损和粘着磨损。     

聚合物基复合材料摩擦磨损性能的研究进展

介绍了聚合物基复合材料结构与组成对其摩擦磨损特性影响方面的研究;分别讨论了不同聚合物基体、不同的填料及固体润滑剂对复合材料摩擦因数及磨损率的影响;讨论了表面处理技术、滑动速度、滑动距离、载荷、对磨面的特性及温度等条件对复合材料的摩擦磨损性能的影响,并探讨了其摩擦、磨损机理.     

聚四氟乙烯碳纤维增强双马来酰亚胺复合材料的摩擦学性能

研究了不同含量PTFE碳纤维增强双马来酰亚胺复合材料的力学和摩擦学性能,并分析了在干摩擦和水润滑条件下的磨损表面形貌和磨损机制。结果表明:添加质量分数10%~15%PTFE的复合材料体系机械性能最佳,随PTFE含量的增加,复合材料的摩擦因数下降,而磨损率呈上升趋势。水润滑下,摩擦因数和磨损率比干摩擦下都有相应的降低。干摩擦下,材料的磨损主要以塑性变形、微观破裂及破碎为主;水润滑下,这一机制明显减弱,主要表现为微切削形态。     

硫酸钙晶须填充PTFE复合材料的摩擦学性能研究

用硫酸钙晶须(CSW )填充改性聚四氟乙烯(MVE),采用模压成型工艺制备不同硫酸钙晶须含量的PTFE/CSW复合材料;利用摩擦磨损试验机研究硫酸钙晶须对PTFE/CSW复合材料摩擦学性能的影响,利用扫描电子显微镜对PM复合材料的磨损表面进行微观分析.结果表明:填充硫酸钙晶须提高PTFE复合材料的耐磨损性能,但复合材料的摩擦因数略高于纯PTFE;纯PTFE的磨损机制为黏着磨损,而PTFE/CSW复合材料的磨损机制为轻微磨粒磨损和黏着磨损共同作用.当硫酸钙晶须质量分数大于10%时,PTFE/CSW复合材料的磨损机制逐渐转变为严重的磨粒磨损.     

超声振动切削SiCp/Al复合材料的刀具磨损试验

分别采用超声切削和普通切削两种方式对SiCP/Al复合材料进行了车削试验,研究了切削参数对硬质合金YG6刀具磨损的影响规律,并在同等条件下与聚晶金刚石(PCD)刀具进行了对比。发现超声切削的刀具磨损量要小于普通切削的刀具磨损量;超声切削时PCD刀具的磨损量约为YG6刀具磨损量的1/10,这点和普通切削十分相似。     

室温及气氛条件下铜基自润滑复合材料的摩擦磨损性能研究

采用粉末冶金法制备了3种铜基自润滑复合材料,分别考察了它们在室温及气氛条件下的摩擦磨损性能,通过对复合材料的力学性能和磨痕表面形貌、成分的分析,探讨其摩擦磨损机制.结果表明:Cu-9%石墨、Cu-4.5%石墨-4.5%MoS2、Cu-9%MoS2复合材料的密度、硬度和抗弯强度值都依次增大;室温条件下,因石墨与Cu的硫化物协同润滑作用,Cu-4.5%石墨-4.5%MoS2复合材料的摩擦磨损性能最好;气氛条件下,因Cu的硫化物发挥了其自润滑作用,Cu-9%MoS2复合材料表现出最佳的减摩耐磨性能,而Cu-4.5%石墨-4.5%MoS2复合材料次之;铜基自润滑材料的基体强度与固体润滑膜的覆盖率,是影响摩擦磨损机制转变的关键因素.