高性能复合陶瓷刀具材料

高性能陶瓷刀具材料需具备高硬度、高耐磨性和耐热性、抗粘结性和化学稳定性等性能 .讨论了复合陶瓷刀具材料结构与性能之间的关系 .从材料设计的角度 ,提出复合陶瓷刀具材料的设计思路和高性能陶瓷刀具的设计原则 ,详细讨论了设计原则中几个重要的性能指标和性能复合原则 .随着相关学科在理论和方法上的进展、交叉和测试手段的进步 ,高性能陶瓷刀具材料的设计会从定性分析逐渐步入定量描述的阶段 .     

Tribological Properties of PVA-H Composites Reinforced by Nano-HA Particles

The friction and wear behaviors of tribological mechanical components were studied on a four-ball tester under dry conditions, and the wear mechanism was analyzed by observed worn surface using a scanning electron microscope （SEM）. It was found that the friction and wear properties were improved by the addition ofnano HA particles. The composite containing 1 wt% nano HA had the optimum friction coefficient. It is also found that the addition of nano HA increases the wear resistance of oure PVA-H and PVA-H composites.     

载荷对Kevlar/PTFE纤维混杂织物摩擦学性能的影响

采用电子小样织机机织Kevlar/PTFE纤维混杂织物,借助于MMU-5G端面摩擦磨损试验机,激光扫描共聚焦显微镜（CLSM）,考察了Kevlar/PTFE纤维混杂织物在高速、干摩擦时不同载荷下的摩擦磨损性能。结果表明,在转速为300 r/min下,载荷越高,稳态摩擦系数值越低,随着载荷的不断增加,稳态摩擦系数下降趋势变缓;织物磨损深度随载荷增加而增加,但磨损率反而降低,织物的摩擦磨损与织物结构有关,磨损方式主要为磨粒磨损,以及PTFE在法向载荷挤压和摩擦剪切作用下发生塑性变形。     

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．     

非傅立叶模型层状复合陶瓷结构热传导分析

用非傅立叶热传导模型分析层状复合陶瓷结构的温度场,并与单热涂层结构的结果进行比较,同时进一步研究了夹层热物理性能参数对温度场的影响。研究表明：夹层可以有效地减缓内部结构的温度变化,夹层热物理性能参数（如：松弛时间、声速）对结构层的温度场有明显影响。     

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．     

Preparation and mechanical properties of Al<Subscript>2</Subscript>O<Subscript>3</Subscript>/Al laminated ceramic matrix composites

Three series of Al2O3/Al laminated ceramic matrix composites,named SPA,SPV and HP,were fabricated by different methods.SPA and SPV were prepared using Al2O3 slices and Al slurry via screen printing and subsequent heat treatment in air or vacuum.HP samples were made by hot pressing the layered stack of Al foils and Al2O3 slices.SEM and XRD were applied to analyze the microstructure and the interlayer crystal phase.The bending strength,fracture toughness and fracture work of the samples made by the three methods were measured and compared.The results show that the composites have much better toughness and higher fracture work than the Al2O3 slice.Among the samples made by the three methods,the samples made by hot pressing have the optimum mechanical performance.The displacement-load curves and fracture mechanism were analyzed.     

陶瓷材料在纺织业中的应用

在介绍陶瓷材料优异性能的同时，从用陶瓷制备纺织器材、纺出陶瓷纤维以及使用陶瓷微粉开发功能性纺织品3个方面综述陶瓷材料在纺织行业中的应用现状。     

Tribological Properties of Polyvinyl Alcohol Hydrogel Reinforced with Nanometer Hydroxy Apatite

As a potential artificial cartilage material, the friction and wear properties of nano-hydroxy apatite （HA） particles filled poly （vinyl alcohol） hydrogel （PVA-H） composites sliding against stainless steel disk under water lubrication condition were studied by using a four ball tester. The worn surfaces were investigated by using a scanning electron microscope （SEM） to determine the wear mechanisms. Experimental results show that filling HA to PVA-H will slightly increase the friction coefficient of composites with the increasing of HA content under water lubrication condition. Meanwhile, HA particles can greatly reduce the wear mass loss of the PVA-H composites and enhance the load carrying capacity, the wear loss of the 1 wt% HA reinforced PVA-H composites can be decreased by 30 percent under 2.0 MPa to 50 percent under 0.5 MPa contact pressure. We also found that 2 wt% HA content of composites increase the wear mass loss under the same condition. SEM examination shows that the worn surface of low HA containing （1 wt%） composites are much smoother than that of pure PVA-H or high HA containing （2 wt%） composites under 1.5 MPa contact pressure. It is also found that there are big hole and big reunited HA particles in the surface of 2 wt% HA containing composites, which leads to deterioration of the surface of samples under higher loads in water lubrication. These results may be useful in the tribological design of artificial articular cartilage material.     

陶瓷材料的抗热震参数

通过求解无限大平板第三类边界条件的瞬态温度场及瞬态热应力场,分别建立了表面冷却条件下引起平板表面临界应力的临界温差ΔTc的表达式和表面加热条件下引起平板中心面临界应力的临界温差ΔTc′的表达式.计算结果表明,无限大陶瓷平板的ΔTc远远小于相同Biot模数条件下的ΔTc′,而且表面冷却条件下表面达到临界热应力的量纲一时间也小于表面加热条件下中心面达到临界热应力的量纲一时间.     

Tribological Property of Polyimide Porous Materials

Polyi mide(PI)is a kind of macromolecule mate-rial developed since the1950s,having superior physi-cal mechanical properties,resistance to hightempera-ture,resistance to acid and alkali,and excellent selflubricating property.Hence,it is widely applied inhigh and new-technology fields,such as the militaryindustry,electronic industry and aerospace indus-try[1].However,in the current research on the fric-tion performance of PI materials,the most concernedtopic is PI fil m materials,and it is sel…     

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。     

气体放电条件下负载光催化剂陶瓷的实验研究

选取A、B两类陶瓷材料作为负载光催化剂的载体．通过对陶瓷材料性质的实验研究并将其作为管线式气体放电填充床反应器的填充料对含苯气体进行处理，得出了不同粒径的陶瓷载体在高电压下对苯转化率的影响规律，高孔隙率的陶瓷载体对苯的转化率较高，高孔隙率的陶瓷负载光催化剂后对较高浓度苯气体的转化率达到94．9％．     

冲击载荷下磁性层合梁的缓冲及衰减特性

利用在冲击载荷下磁性层合结构的层间发生滑移,进而引起刚度降低和摩擦耗能的特点,提出磁性层合缓冲及衰减的概念,研究在冲击载荷下磁性层合梁的缓冲和衰减性能。采用FEM方法分析了冲击载荷下磁性层合梁的冲击响应。通过与同样厚度的单层梁进行比较发现,在一定幅值范围的冲击载荷下,磁性层合粱不仅能使冲击响应最大峰值明显降低,而且能使冲击后的自由振动迅速衰减。     

Effect of counterface materials on friction and wear behavior of double glow glasma discharge surface alloying on Ti22Al25Nb alloy

Samples of surface chromising layer were prepared by the double glow plasma discharge technique. X-ray diffraction and X-ray photoelectron spectroscopy(XPS) analysis of different elements confirmed the formation of chrome in the layer. Their tribological properties were investigated by pin-on-disk tribometer. Silicon nitride, GCr15, and nickel-based alloy were selected as counterface materials. Results indicated that the lowest friction coefficients and wear rate were obtained when substrate and chromising layer against nickel-based alloy, and tribological properties of chromising layer were better than those of substrate. The highest friction and wear rate were samples against silicon nitride alloys. In the case of three rubbing pairs, the unchangeable materials against different hardness counterfaces leaded to different wear mechanisms. Samples against silicon nitride exhibited abrasive mechanism, and when GCr15 and nickel-based alloy were used as counterface, transfer film and glaze layer formed on the contact surface, which played the main role in decreasing friction and wear. Funded by the Natural Science Foundation of Jiangsu Province China(No.BK2005128), and the Scientific Research Foundation of Nanjing University of Information and Technology     

Tribological properties of nano-porous anodic aluminum oxide template

A highly ordered porous alumina template with pores of 45 nm in diameter was synthesized by a two-step electrochemical anodizing process.The influence of pore-enlargement treatment on the porous structure and tribological properties of the film was investigated,and ultrasonic impregnation technology was applied on it to form self-lubricating surface.The structure of the self-lubricating film and its tribological properties were investigated in detail.It can be concluded that the optimum time of pore-enlarge...     

Processing and mechanical properties of network ceramic/steel composites by pressureless infiltration

A new style Ni-containing alumina ceramic foam based continuous three-dimensional interconnected skeleton was prepared by impregnating a polymeric sponge with aqueous ceramic slurry.Subsequently,alumina ceramic foam/steel metal matrix composites（MMCs） were prepared successfully by sand mold casting technique.The microstructure and mechanical properties of MMCs were investigated by SEM,EDS and compressive test.The results show that the depth of infiltration is about 40 μm to the bonding interface of ceramic/steel and the fracture strength σmax and plastic strain limit εp of composite are 520 MPa and 11.2%,respectively.The fretting wear mechanism of MMCs is mainly performed at the oxidative wear mode with lower load/friction frequency and the predominant oxidation wear together with slight adhesive wear and abrasive wear multiple mode with higher load/ friction frequency.Moreover,the infiltration bonding and continuous three-dimensional interconnected ceramic skeleton play a vital role in the stability of the bonding interface and excellent mechanical properties.     

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.     

耐高温改性酚醛树脂性能研究

以三聚氰胺、腰果壳油为改性剂改性的酚醛树脂，性能优越于纯酚醛树脂．以改性树脂为基体研制的摩擦材料，其耐热性能、摩擦磨损性能和机械性能均较高，特别是高温摩擦磨损性能优越。     

Sialon陶瓷的磨粒磨损行为

Sialon陶瓷的磨粒磨损行为研究结果显示：较高载荷作用下,磨损量随时间呈指数关系增加;较低载荷作用下,磨损初期有一个短暂的磨损量基本不变的孕育阶段,随后进入快磨损阶段,对该孕育现象进行了探讨,通过实验表明,磨损量与转速有线性关系但与载荷无线性关系,SEM对磨损表面分析发现,Sialon陶瓷在SiC磨粒作用下的磨损机理主要是犁耕和表面断裂脱落。