共查询到18条相似文献,搜索用时 171 毫秒
1.
2.
3.
4.
5.
摩擦材料的特性决定了制动器的制动性能对温度的敏感程度,这是制动性能稳定性的主要影响因素之一。不同摩擦材料热衰退性能有较大差异,本文对采用粉末冶金摩擦材料的制动器和采用陶瓷摩擦材料的制动器进行了试验研究,对比分析了其性能差异。 相似文献
6.
《新型炭材料》2020,(1)
采用薄膜沸腾CVI以LaCl_3催化热解二甲苯、浸渍树脂及高温处理后获得密度为1. 72~1. 73 g/cm~3的炭/炭(C/C)复合材料,应用激光热导仪、摩擦试验机及扫描电镜等研究了催化剂含量对材料导热和摩擦性能的影响。结果表明,催化剂含量由0增加至15 wt%时,材料的热导率先升高后降低,摩擦系数及磨损率的变化与之相反。含量6 wt%下材料的导热性能较高,垂直与平行摩擦面方向的热导率最大分别为40. 3和86. 1 W/(m·K),较含量为0时提高约58. 5%和75. 6%;制动过程中,摩擦面易于形成纳米丝状碳增强的光滑摩擦膜,是该含量下材料摩擦系数和磨损较低、制动稳定性高的重要原因。 相似文献
7.
现代汽车用非石棉摩擦材料的进展 总被引:2,自引:0,他引:2
摩擦材料广泛用于各种交通运输工具(如汽车、火车、飞机、舰船等)和各种机器设备的制动器、离合器及摩擦传动装置中的制动材料。在制动装置中,利用摩擦材料的摩擦性能,将转动的动能转化为热能及其他形式的能量,从而使传动装置制动。 现代汽车摩擦材料是一类以摩擦为主要功能,兼有结构性能要求的复合材料。在工作时主要承受反复变化的机械应力场与热应力场,而力与热的发生源是无限形成新工作面的摩擦界面。汽车用摩擦材料主要是制动摩擦片和离合器片,它们既是保安 相似文献
8.
9.
采用热模压成型工艺制备CaSO_4晶须增强树脂基复合摩擦材料(试样A),并选用一种市售材料(试样B)作对比,研究制动频率对两种材料摩擦学性能的影响,利用SEM及EDAX观测磨损表面形貌与表面膜成分变化,并分析其磨损影响机理。结果表明:随着制动频率的变化,由于CaSO_4晶须的增韧补强作用,试样A的摩擦因数始终维持在较高水平0.48左右,制动平稳可靠,对偶件损伤程度轻,磨损机理以磨粒磨损为主;而试样B的摩擦因数则是先降低后升高,且对制动速率的变化敏感,磨损机理以黏着磨损和氧化磨损为主。两种材料摩擦表面温度及磨损率均随着制动频率的变化而升高,但在制动频率小于35次时,两种材料均表现出良好的耐磨性。 相似文献
10.
11.
An analysis of thermoelastic contact problem of functionally graded (FG) rotating brake disk with heat source due to contact friction is presented. Finite element method (FEM) is used. The material properties of disk are assumed to be represented by power-law distributions in the radial direction. The inner and outer surfaces considered are metal and ceramic, respectively. Pure material is considered for the brake pad. Coulomb contact friction is assumed as the heat source. It is divided into two equal parts between pad and brake disk which leads to thermal stresses. Mechanical response of FG disks are compared and verified with the known results from the literatures. The results show that the maximum value of radial displacement in mounted FG brake disk is not at outer surface. It is found that the all areas between pad and brake disk is in full-contact status when the ratio of pad thickness to brake disk thickness is 0.66. It is observed that the total strain due to thermomechanical load is negative for some parts of the disks, whereas, the thermal strains are always positive. It can be concluded that gradation index of the metal-ceramic has significant effect in the thermomechanical response of FG disks. 相似文献
12.
13.
Jiusheng Bao Yan Yin Zhencai Zhu Minming Tong Yuhao Lu Yuxing Peng 《Applied Composite Materials》2013,20(4):331-339
The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures. 相似文献
14.
以普通酚醛树脂、硼改性酚醛树脂、三聚氰胺改性酚醛树脂为黏结剂,以陶瓷纤维为增强纤维,制备了3种酚醛树脂陶瓷摩擦材料。对其冲击韧性和硬度进行实验测试,采用摩擦磨损试验机考察其摩擦磨损性能,采用扫描电子显微镜(SEM)和X射线能谱仪分析其磨损表面形貌及其成分,并探讨其磨损机制。结果表明:硼改性酚醛树脂黏结剂能够提高摩擦材料的硬度,三聚氰胺改性酚醛树脂黏结剂能够提高摩擦材料的冲击韧性,降低摩擦材料硬度;在摩擦过程中三聚氰胺改性酚醛树脂在高温下炭化,在摩擦材料表面形成一层致密的摩擦层,摩擦层的存在使摩擦材料的摩擦因数相对比较稳定,降低了摩擦材料的磨损率。 相似文献
15.
16.
The aim is to study the effect of several distinct manufacturing processes, parameters and ingredients on the physical, mechanical and frictional characteristics of brake pad developed using hand lay method (sample 1), brake pad developed using hot compression method (sample 2) and commercial brake pad (sample 3). The non asbestos brake pad samples were compared with the selected commercial brake pad sample using pin on disc test set up. Results showed that friction performances of all three samples were insensitive to water and oil absorption test. Sample 2 had better mechanical properties and greater wear resistance than other two samples which are attributed to use of hot press method of manufacturing the composite and selecting the carbon-based ingredients. Sample 1 maintained high coefficient of friction even though manufactured with the help of hand lay method. Both fabricated brake pads are stable upto the temperature 220 °C without any weight loss and degradation. Brake pad surfaces showed different shape wear debris and plateaus significantly affecting the friction characteristics. Finally, the test results indicated that both fabricated brake pad samples have potential braking characteristics to be used as a brake pad material. 相似文献
17.
随着我国的汽车工业进步,对汽车制动器衬片的质量和性能提出了更高的要求。而我国汽车制动器衬片生产企业的生产能力和水平与发达国家还有一定差距。目前我国汽车制动器衬片执行GB5763,摩擦材料标准化技术委员会正在试图等同采用更为先进的ISO15484体系。ISO15484对汽车制动器衬片产品的设计、研发、试生产到批量生产各个环节进行规定,在此过程中,台架试验成为非常重要的手段。新标准的等同采用将使生产许可证工作发生相应变化。作为强制的行政许可,适时的采用新标准作为企业取证的基本要求和产品检验依据,将促进行业的整体进步。而这一变化尚需时日,有待于新标准逐渐的被企业和行业所认同、接纳和采用。 相似文献
18.
Attempts have been made for the first time to prepare a friction material with the characteristic of thermal sensitive modulus, by the inclusion of thermoplastic elastomers (TPE) as viscoelastic polymeric materials into the formulation in order to the increase the damping behavior of the cured friction material. Styrene–butadiene–styrene (SBS), styrene–ethylene–butylene–styrene (SEBS) and nitrile rubber/polyvinyl chloride (NBR/PVC) blend system were used as TPE materials. In order to evaluate the viscoelastic parameters such as loss factor (tan δ) and storage modulus (E′) for the friction material, dynamic mechanical analyzer (DMA) were used. Natural frequencies and mode shapes of friction material and brake disc were determined by modal analysis. However, NBR/PVC and SEBS were found to be much more effective in damping behavior. The results from this comparative study suggest that the damping characteristics of commercial friction materials can be strongly affected by the TPE ingredients. This investigation also confirmed that the specimens with high TPE content had low noise propensity. 相似文献