双元炭基体刹车盘在飞机中止起飞时的高摩擦特性

为解决炭刹车盘在飞机中止起飞（RTO）时摩擦系数低的弱点,采用了针刺炭纤维无纬布准三向预制体,以狭缝定向流外热内冷、内热外冷热梯度CVI与树脂浸渍-炭化相结合的致密工艺,生产了双元炭基体的波音757-200型飞机炭刹车盘材料.与原装机的国外炭刹车盘在惯性台上进行了RTO动态力矩对比试验,结果表明：具有粗糙层结构热解炭与树脂炭优化组合的双元炭基体超码炭刹车盘,比国外单一粗糙层结构热解炭基体的炭刹车盘RTO时的摩擦系数提高了22.7%～29.2%,突破了炭刹车盘在飞机RTO动态力矩试验中摩擦系数严重衰减这个长期难于攻克的关键技术.     

原位炭补强整体粘接处理对炭刹车盘材料性能的影响

采用原位炭补强整体粘接修复飞机炭刹车盘的方法,与国外常用的“二合一”铆接修复方法相比,不改变Dunlop炭刹车盘材料的摩擦特性,对母体材料的密度、硬度、表面孔率,经加工过的影响也不明显,但其导热系数比“二合一”铆接炭刹车盘材料提高了30％,改善了飞机炭刹车盘材料修复后的整体性,可靠性和安全性,是一种技术创新的修复方法,除用于B757-200飞机炭刹车盘材料的维修外,还用于其他型号飞机炭刹车盘材料的维修。     

飞机炭刹车盘制备中各工艺参数对其摩擦磨损性能的影响

炭/炭刹车盘的摩擦磨损性能对飞机获得高能量刹车时的高摩擦磨损特性有重要的影响。通过控制炭/炭(carbon/carbon,C/C)复合材料制备过程中各工艺参数可以得到高性能刹车的炭刹车盘。影响C/C复合材料摩擦性能的因素有很多,综述了国内外研究现状,本文讨论了炭纤维预制体、致密化过程、高温热处理和机械加工对炭刹车盘摩擦磨损性能的影响以及这几个工艺参数的协同作用。     

文摘

飞机刹车用长寿命高摩擦特性炭/炭复合材料制备技术(英文)[刊,中]/苏君明,肖志超,刘勇琼,等//新型炭材料,2010,25(5):329～334以针刺炭纤维准三向结构整体毡为预制体,经丙烯气体狭缝定向流的"外热内冷"、"内热外冷"径向热梯度CVI工艺致密技术,优化组合的热解炭/树脂炭双元炭基体技术,通过调控高温处理技术等三大关键技术制备了A320系列飞机炭刹车盘材料。     

炭/炭复合材料的摩擦磨损性能及应用

论述了炭／炭复合材料的特点，结合该材料在飞机刹车盘中的具体应用，讨论了炭／炭复合材料在不同环境气氛下的摩擦磨损行为及其影响因素，并阐明了炭／炭复合材料的研究现状和尚需解决的问题。     

影响飞机炭刹车盘使用寿命的因素研究

采用ChaomaA320炭刹车盘进行了地面台架动力矩试验及装机应用.实测了炭刹车盘的磨损率及使用寿命,并与装机应用的法国Sepcarb(R)ⅢORA320炭刹车盘的平均使用寿命进行了对比.分析了刹车能量、炭盘温度、环境条件及飞行员操作习惯等对炭刹车盘材料磨损率的主要影响,以及钢央/铆钉配件技术、防氧化涂层状态对炭刹车盘使用寿命的制约.结果表明,ChaomaA320炭刹车盘的实际使用寿命可达到2 700～3 000次起落,比法国Sepcarb(R)ⅢORA320炭刹车盘的平均使用寿命2 200次起落,提高了23％～36％;并归纳了ChaomaA320炭刹车盘台架磨损率与装机应用的外场实际磨损率之比为1:1.88～2.09的对应关系.     

文摘

阳极焙烧炉内煤气流动和燃烧的数值模拟,阳极焙烧炉的热工测试及分析,碳团簇型吸波材料的结构与性能研究,大型电解铝厂选址新理念,飞机机轮炭／炭刹车盘金属件铆接工艺分析,大型铝电解槽侧部破损原因分析及对策,焙烧炉烟气污染防治对策的探讨.[编者按]     

炭／炭复合材料飞机刹车盘的湿态刹车性能

本文研究了炭／炭（Ｃ／Ｃ）复合材料飞机刹车盘（简称炭盘）的湿态刹车性能，分析了炭／炭复合材料的湿态摩擦机理，结果表明，炭盘的刹车性能有湿态下明显衰退，随着刹车比压，刹车能量的增大，其湿态刹车性能进一步衰减。     

化学气相沉积炭/炭复合材料研究进展

炭/炭复合材料被成功用于许多领域,主要用作抗烧蚀、热防护和刹车材料,如飞机的刹车盘、导弹的头锥等.化学气相沉积是制备炭/炭复合材料的关键技术,本文阐述了炭/炭复合材料化学气相沉积工艺原理,论述了化学气相沉积热解炭机理的研究现状,介绍了不同种类化学气相沉积工艺的特点,以及化学气相沉积工艺计算机数值模拟技术的研究进展.提出了炭/炭复合材料化学气相沉积技术的研究方向和发展趋势.     

高温热处理对C/C复合材料刹车盘尺寸的影响

研究了用CVI工艺制备的二维C／C复合材料刹车盘在进行高温热处理时的尺寸变化。第一次热处理时刹车盘直径增大，厚度减小；第二次、第三次热处理时刹车盘直径和厚度均增加。随着热处理次数的增加，刹车盘尺寸变化越来越小，趋于稳定。刹车盘尺寸的变化与C／C复合材料中碳原子的有序化重新分布和不同炭相产生应力裂纹等因素有关。     

C/C刹车盘制备工艺的研究

选择整体针刺毡为预制体，致密化工艺采用气相沉积(CVD)，以天然气和丙烷的混合气体为原料，制备C／C刹车盘。其热解炭以粗糙体为主，摩擦曲线平稳，没有湿态衰减，沉积时间短。     

碳/碳化硅复合材料刹车盘/片热应力场分析

采用有限元方法分析二维正交碳纤维增强碳化硅(C/SiC)复合材料制成的汽车刹车盘/片在刹车过程中引起的非线性热力耦合行为,主要研究在强制对流和热辐射作用下刹车结构的温度变化,讨论不同材料属性对刹车温度场的影响以及在温度场和膨胀系数耦合下C/SiC刹车盘/片中热应力和形变情况。数值结果表明:在双重散热条件下需要更多时间用于降温,而垂直于刹车面的热导率分量对温度传导或者降温影响较大;对于C/SiC刹车盘/片每一次刹车行为等效于一次热应力的加载和卸载,而每次产生的热应力可能突破C/SiC的极限弹性强度引起的残余塑性形变,而这种不断累积的残余效果继而引起C/SiC刹车盘/片失效。     

Development and tribological studies of a novel metal-ceramic hybrid brake disc

Ceramic matrix composite (CMC) friction materials show promising tribological properties. Typically, carbon ceramic brake discs consist of a C/SiC rotor which is joined to a brake disc bell. Within this work, a novel metal-ceramic hybrid brake disc, consisting of C/SiC friction segments which are mounted by screws onto an aluminum carrier body, was designed and investigated. A prototype was built which was tribologically tested with three different brake pad materials, LowMet reference, modified SF C/SiC as well as C/C. A constant starting sliding velocity of 20 m/s and braking pressures of 1, 2, and 3 MPa were investigated. To simulate emergency braking conditions 10 consecutive brake applications were carried out in close succession for each brake pad material and braking pressure. The C/C brake pad material showed the highest average coefficient of friction followed by the LowMet and C/SiC material. However, the wear rates of the C/C and LowMet material were orders of magnitude higher compared to the C/SiC material.     

节能环保型汽车制动盘涂装线的进展与应用

介绍了制动盘涂装的特殊要求,以及制动盘涂装线的进展和机器人喷涂技术的应用。通过传统技术与机器人喷涂新技术的性能比较,揭示了其广阔的应用前景。     

盘式制动器热应力场仿真分析

为了有效检测盘式制动器的性能，利用ANSYS建立了盘式制动器热应力三维有限元分析模型，探讨其在摩擦副作用下热应力分布的特点和规律，为优化盘式制动器的性能提供一些参考。     

SiC particle reinforced Al matrix composites brazed on aluminum body for lightweight wear resistant brakes

Aluminum alloys are well known light-weight alloys and very interesting materials to optimize the strength/weight ratio in order to reduce automotive vehicle weight, fuel consumption and CO₂ emissions; unfortunately, they are also relatively soft and therefore cannot be used for high wear applications.The aim of this work was to develop an aluminum alloy brake disc with wear-resistant SiC particle reinforced aluminum matrix composites (SiC/Al) joined on to its surface.Different approaches based on brazing or shrink fitting joining technologies were used to join SiC/Al to the aluminum alloy surface.A functional graded structure was built by brazing thin layers of aluminum matrix composites reinforced with progressively higher amount of SiC particles by using a Zn–Al based alloy as joining material. Several samples were prepared by shrink fitting and brazing: 40 mm x 40 mm x 10 mm samples and a 100 mm diameter brake disc with 68% SiC particle reinforced Al matrix surface and aluminum alloy A365 body. Tribological tests demonstrated that an aluminum alloy brake disc with wear-resistant SiC particle reinforced aluminum matrix composites (SiC/Al) brazed on its surface is a promising technical opportunity.     

Oxidation behaviour of C/C–SiC brake discs tested on full-scale bench rig

C/C–SiC composites are considered to be strong candidates for the new generation of high-speed train brake discs. To achieve a better application, it is necessary to improve understanding of the oxidation behaviour of C/C–SiC brake discs after a full-scale bench test rig. In this study, full-scale braking bench tests for C/C–SiC self-mated brake pairs were conducted under a braking speed of 350–420 km/h and a braking pressure of 17–28 kN. Moreover, the oxidation behaviour and mechanisms of the C/C–SiC brake discs during the practical braking process were investigated. The results indicate that the oxidation behaviour is highly dependent on the friction surface region of the C/C–SiC brake disc owing to the distribution of microcracks, the formation of friction films, the difference in temperature, and the contact content with O₂. Specifically, the oxidation depths of the friction layer on the inner circumferential surface, middle friction surface, and outer circumferential surface were 278.3, 252.1, and 359.9 μm, respectively. Furthermore, the oxidation reaction preferentially occurs in the active area of the C fibre and pyrolytic carbon (PyC) during the braking process.