Effects of Forming Pressure on the Porosity of Polyimide Porous Materials

Based on a series of experiments, the theory of relationship between normal pressure and pores＇ characters fit for polymer was set up for the first time. On the study of relation between normal pressure and porosity, experience model of polyimide porous materials was proposed which is similar to the traditional expe- rience model of the metal porous material. While being pressed, polyimide was found soon to come into elasto- plastic deformation progress in this paper, so the theory model of metal porous material based on Hooker＇s law was not fit for the polymer any more. A new elasto-plastic deformation and exhausting model is proposed which shows better agreement with polymer material＇s pressing process.     

稀土化合物填充PA1010复合材料的摩擦学特性

采用热挤压注模方法制备了含不同稀土化合物如CeO2,LaF3,La2O3的尼龙1010（PA1010）复合材料。测定了复合材料的密度和硬度,在MM－200型环－块实验机上考察了其摩擦磨损性能,用光学显微镜观察了材料表面磨痕和转移膜形貌。研究结果发现,添加稀土化合物可改变PA1010的摩擦学性能,尤其是填充La2O3的PA1010复合材料的减摩、耐磨性能均最佳,PA1010的磨损主要表现为粘着、劳和逆性变形,其转移膜不连续,且有脱落现象,PA1010－15％La2O3复合材料的磨损主要为磨粒磨损,其转移膜致密光滑,薄而完整,这与其耐磨性最好的现象相一致。     

三层复合轴承材料的试验研究

本文对研制的聚四氯乙烯和聚甲醛两种三层复合轴承材料进行摩擦磨损试验研究，并就轴承摩擦到表面结构对磨损性能的影响进行了试验分析，其结果可供实际应用时参考．     

GF增强尼龙1010复合材料的磨擦学性能研究

制备了玻璃纤维（GF）增强尼龙1010复合材料,在环一块磨损试验机上研究了复合材料的摩擦学性能。结果表明：GF含量对复合材料的摩擦学性能有显著影响,GF质量分数为35％时增强效果较好;随着滑速的增加,GF增强尼龙1010复合材料的摩擦系数和磨损量持续上升。干摩擦下的复合材料磨损以疲劳断裂和粘着为主,且纤维出现磨损、断裂及从基体中剥落的现象。在油润滑下材料向对偶产生轻微的转移,与干摩擦相比复合材料的摩擦系数和磨损量大为降低;水润滑下的尼龙以化学腐蚀磨损和磨粒磨损为主,此时复合材料摩擦系数也有较大程度的降低,但磨损量较干摩擦增大。     

SiC颗粒填充PTFE复合材料耐磨性能的研究

利用M－200型环一块大材料磨损试验机，对机械混合法制备的SiC陶瓷颗粒填充聚四氟乙烯（PTFE）复合材料在干摩擦条件下的磨损特性进行了研究，并利用扫描电子显微镜(SEM)对TFE复合材料的磨损表面形貌进行了观察。结果表明SiC颗粒入大大提高了PTFE的耐磨性能，颗粒的添加量、磨损载荷、磨损温度影响复合材料耐磨性能的重要因素。     

碳纤维/环氧复合材料制备工艺对自润滑性能的影响

本文探讨了采用碳纤维/环氧树脂复合材料制造自润滑轴承的基本工艺。对不同固化剂对材料的自润滑性能进行了试验分析,并对比其结果。使用电子显微镜及光学显微镜对断口及摩擦表面进行了观察。     

SiC颗粒增强PTFE基复合材料摩擦磨损特性研究

利用冷压烧结法制备了不同含量的SiC颗粒填充聚四氟乙烯(PTFE)复合材料，采用M-200环块试验机进行摩擦磨损试验，研究了SiC颗粒增强PTFE基复合材料在干摩擦条件下的磨损特性，并利用扫描电子显微镜对复合材料的磨损表面形貌进行了观察，对复合材料的磨损机制进行了分析．结果表明：SiC颗粒增强复合材料的耐磨性能显著提高，但其摩擦系数有所增大；随SiC颗粒含量的增加复合材料的磨损机理由粘着磨损占主导逐渐转变为显微切削占主导；复合材料中增强相SiC颗粒有3种流失形式：整体脱落、磨损、碎裂．     

Tribological behaviors of spot-textured TiN coatings on M2 high-speed steel under boundary lubricated conditions

The effect of sliding duration on the tribological behaviors of spot patterned coatings was investigated. Two patterns based on physical vapor deposition （PVD） TiN coatings were used, such as, in-lined （IN） and staggered （ST） spots. The tribological behaviors were evaluated by using a Cameron-Plint wear test rig. The M2 steel discs deposited TiN coatings with IN and ST patterns slid against the ASSAB 17 tool steel pins at a speed of 0.23 m/s, in Shell Tellus T32 lubricant and were loaded with 900 N. The testing results on disc specimens with two types of PVD TiN spot patterns, all coated with a bias voltage of-180 V and slid for 4, 8 and 11 h respectively, were presented. The results revealed that the in-lined coatings possessed relatively better wear behaviors than the staggered pattern coatings. Mechanisms for such superiority and for the cause of peeling were discussed. A relevant design approach was suggested for the application of such patterned coatings.     

无机纳米杂化聚酰亚胺薄膜的制备及耐局部放电特性

通过正硅酸乙酯及异丙醇铝在聚酰胺酸的N,N′-二甲基乙酰胺溶液中的溶胶凝胶反应,制备出了具有一定SiO2和Al2O3质量分数的聚酰亚胺复合薄膜,并且分别利用傅里叶变换红外光谱和原子力显微镜对薄膜进行测试和微观结构分析,研究表明,所制得的复合薄膜中有机相和无机相形成了很好的纳米复合体系,经电晕试验研究发现该复合薄膜具有优异的耐局部放电特性,该复合结构对开发新型工程电介质材料有着重要的推动作用。     

聚酰亚胺金刚石树脂砂轮耐磨性能研究

介绍了一种新型金刚石砂轮结合剂——超细增韧聚酰亚胺树脂粉。磨削试验结果表明：该树脂粉制作的金刚石砂轮其耐磨性、磨削效率和所加工工件的表面质量明显优于酚醛树脂金刚石砂轮。通过扫描电镜观察两种树脂砂轮的显微组织,找出了两种树脂砂轮耐磨性存在差异的原因,树脂耐热温度的高低直接影响砂轮的耐磨性。     

Tribological behavior of MC Nylon6 composites filled with glass fiber and fly ash

To improve tribological property of MC Nylon6,the glass fiber and fly ash reinforced monomer casting nylon composites(GFFAPA)were prepared by anionic polymerization of ε-caprolactam.The friction and wear behaviors of composites under dry condition,water lubrication and oil lubrication were investigated through a ring-black wear tester.Worn surfaces were analyzed using a scanning electron microscope.The experimental results show that the tensile strength and hardness of nylon composites are obviously improved with reinforcement increasing.Compared to MC nylon,the lowest friction coefficient and wear rate of glass fiber reinforced nylon composites(GFPA)with GF30% respectively decrease by 33.1% and 65.3%,of fly ash reinforced nylon composites(FAPA)with FA20% decrease by 5.2% and 68.9% and of GFFAPA composites with GF30% and FA10% decrease by 57.8% and 89.9%.The main wear mechanisms of FAPA composites are adhesive and abrasive wear and of GFPA composites with high proportion are abrasive and fatigue wear.The worn surfaces of GFFAPA composites are much multiplex and the optional distributing glass fiber and fly ash have a synergetic effect on the wear resistance for GFFAPA composites.Compared with dry friction,the friction coefficient and wear rate under oil lubricated conditions decrease sharply while the latter reversely increase under water lubricated conditions.The wear mechanisms under water lubricated condition are principally chemical corrosion wear and abrasive wear and they become boundary friction under oil lubricated condition.     

复合型低介电常数聚酰亚胺复合材料研究进展

聚酰亚胺具有优异的力学性能及耐热性,一直是微电子产业的重要电介质材料之一。近年来,随着微电子行业的发展和5G通讯技术的兴起,从能耗要求到信号接收等方面都对降低聚酰亚胺的介电常数和介电损耗提出更高的要求。如何在保留聚酰亚胺优异性能的同时尽可能降低其介电常数与损耗是目前亟需解决的问题。本文综述了近年来多孔聚酰亚胺和聚合物填料、无机纳米填料复合改性聚酰亚胺等复合型低介电聚酰亚胺的研究及应用进展,探讨了如何在降低聚酰亚胺介电常数的同时保持其他性能,并对其发展进行了展望,为新型复合型低介电聚酰亚胺材料的设计与制备提供新思路。     

Tribological properties of self-lubricating laminated ceramic materials

In order to improve the tribological properties of ceramic composites, Al2O3/TiC-Al2O3/ TiC/CaF2 self-lubricating laminated ceramic composites were prepared by vacuum hot pressing sintering. Experiments were conducted to get mechanical properties and the friction and wear properties were also measured with friction and wear tester. The worn surfaces were observed by scanning electron microscope （SEM） and energy dispersion spectrum （EDS）. The wear resistance properties and the self-lubricating effect of ceramic composites were analyzed. Results show that the Al2O3/TiC-Al2O3/TiC/CaF2 self-lubricating laminated ceramic composites layers are well-defined with a higher bonding strength and the mechanical performances are uniform enough to overcome the anisotropy of weak laminated ceramic composites. In addition, the fracture toughness of Al2O3/TiC layers is also improved. Its friction coefficient and wear rates decrease with the increase of rotation speed and load. Al2O3/TiC-Al2O3/TiC/CaF2 self-lubricating laminated ceramic composites have good wear resistance because of the tribofilm formed by the CaF2 solid lubricants. The wear mechanisms of Al2O3/TiC/ CaF2 layers are abrasive wear and Al2O3/TiC layers are adhesive wear.     

氮化硅基陶瓷的摩擦磨损特性研究

采用热压烧结方法制备氮化硅和氮化硅基两种陶瓷。利用球-盘式摩擦磨损试验机对氮化硅陶瓷摩擦副在室温干摩擦环境中的摩擦磨损特性试验研究。结果表明：在相同的试验条件下,加入TiC颗粒改善了Si3N4陶瓷的脆性,但耐磨性能提高不大,磨损率略优于Si3N4。Si3N4的磨损主要是磨粒磨损和脆性剥落,而TiC复合材料的磨损表现为磨粒磨损和TiC颗粒的剥落,之后剥落的TiC颗粒又作为磨粒对试样产生更大的磨损,所以导致磨损率提高。     

动态可持续聚酰亚胺电介质材料应用与进展

聚酰亚胺（PI）电介质兼具优异的电气和机械性能以及高的热、化学稳定性,被广泛应用于电力、电子设备的生产制造,是绝缘材料的重要组成部分。近年来随着绿色能源和可持续发展的需求,社会发展更加需要材料在损伤后能够修复、回收等实现再利用。然而,PI由于自身分子结构具有超强的稳定性,分子链在低温条件下难运动,难以实现损伤后的主动修复、回收。因此,必须从本征分子结构角度出发,设计开发适用于PI的新型可逆分子结构来实现材料的动态特性。基于此,该文综述了近期以PI为基体的回收、修复等动态问题的研究,重点介绍目前动态PI的制备方法,发生动态反应的条件以及评估了多种损伤形式之间的关系。首先,总结了自修复PI电介质材料,包括共混、共聚以及设计制备新型结构单体等工艺手段实现材料的修复特性,系统总结了自修复PI当前的发展现状以及面临的困难与挑战。紧接着,主要概述了可降解、可回收PI材料的设计制备,通过动态共价键和动态交联网络择优实现PI电介质的回收。最后,对于目前动态PI体系中存在的问题及未来研究方向进行了总结和展望：可以使用新型动态交联剂结合微量有机或无机物料的复合实现PI材料的动态特性和综合性能的协同提升;通过改善工艺或选择动态交联剂实现PI单体和交联剂粉末级别回收,有效避免降解催化剂的影响;需要进一步设计新型功能性单体,从分子结构水平实现可逆以解决PI修复、降解、回收难的问题。     

Tribological properties of electroless Ni-P-SiC composite coatings in rolling/sliding contact under boundary lubrication

Ni-P-SiC composite coatings were prepared under a given bath composition and operation parameters of electroless plating. The tribological properties of the Ni-P-SiC composite coatings after annealing at 400℃ for 1 h were tested in rolling/sliding contact under boundary lubrication condition using a two-roller tribometer. The measurement contained friction coefficient, contact surface temperature, contact electrical resistance, and wear rate of the Ni-P-SiC composite coatings under various slide to roll ratios, loads, and rolling speeds. For the simultaneous examination of the effect of the chosen parameters on the tribological properties of the Ni-P-SiC composite coatings, an orthogonal regression experimental design method was used.     

新型高强复合胶凝材料的孔结构研究

本文借助于扫描电镜(SEM),x-射线衍射(XRD)和压汞仪等测试手段,比较详细地研究了高强复合胶凝材料的孔结构与强度性能的关系。并且研究了高强复合胶凝材料的孔结构随时间变化的规律。此外,还讨论了高强复合胶凝材料的组成与性能的关系。     

部分稳定二氧化锆减磨性研究

文章全面阐述了部分稳定二氧化锆陶瓷（略作ＰＳＺ）以软金属或软金属氧化物润滑时的摩擦和磨损性能。ＰＳＺ在无润滑时的磨损率随负荷而增加，当负荷超过２０Ｎ时要发生从轻微磨损到严重磨损的转变。Ⅷ─ⅡＢ族软金属及其氧化物可以有效地防止ＰＳＺ的严重磨损，即使负荷达到３５．６Ｎ，磨损率仍保持为零，同时可以将ＰＳＺ的摩擦系数从０．４０减少到０．２０以下．     

Si3N4陶瓷摩擦学的研究和发展

综述了近年来Ｓｉ３Ｎ４ 陶瓷摩擦学研究的发展现状,总结了在干摩擦和润滑的条件下Ｓｉ３Ｎ４陶瓷的摩擦磨损性能、磨损机理以及影响其摩擦磨损性能的因素,提出了今后应重视的几个研究课题．     

微米氧化铝/尼龙复合材料煤泥润滑条件下滚滑摩擦磨损行为

使用微米氧化铝(Al2O3)为增强剂,以尼龙1010为基体,进行氧化铝/尼龙复合材料在煤泥润滑条件下的滚滑动摩擦磨损实验.通过实验发现,水能降低氧化铝/尼龙复合材料的摩擦系数,但增大了磨损量.煤泥润滑时尼龙1010材料的摩擦系数为0.096;氧化铝/尼龙复合材料的平均摩擦系数为0.089,只有纯尼龙的92.7%.尼龙磨损量是3.32mm3;Al2O3/尼龙复合材料的磨损量平均为15.73mm3;Al2O3/尼龙复合材料的平均磨损量平均是尼龙的4.74倍.