Wear Studies on Aircraft Brake Materials

1978 ◽  
Vol 100 (1) ◽  
pp. 98-103 ◽  
Author(s):  
Ting Long Ho

An investigation of both worn surfaces of friction pads and steel rotors which are being applied in current aircraft brakes has been carried out by employing an x-ray diffraction technique. It consists of the analysis of chemical element distribution in the surface layers. The wear particles were also examined by using the scanning electron microscope. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. A wear model was proposed for the current aircraft brake materials. Essentially this model proposed that cracks are formed in the surface layer of the break material due to the normal and fractional stresses. It is primarily surface temperature dependent.

2017 ◽  
Vol 726 ◽  
pp. 316-320 ◽  
Author(s):  
Jie Gao ◽  
You Jun Lu ◽  
Jun Feng Hou ◽  
Zhen Xia Yuan ◽  
Wen Luo ◽  
...  

The Mo powder and Nb powder was used as raw material, the Mo-10Nb alloy target was prepared by different sintering condition (non-pressure sintering and hot pressing sintering). The density, phase composition, microstructure and elemental distribution of Mo-10Nb alloy targets were determined by X-ray diffraction and scanning electron microscopy. The results showed that prepared by hot pressing Mo-10Nb alloy target density of 9.618 g/cm3, grain size 20 ~ 30μm, Mo and Nb element distribution.


2010 ◽  
Vol 165 ◽  
pp. 165-168 ◽  
Author(s):  
Artur Sitko ◽  
Marek Szkodo ◽  
Maria Gazda

This paper presents investigation of surface layers. The diffusion layers were produced by using different parameters of reactive atmosphere (N2:H2). The research of the surface layers was performed using scanning electron microscope (SEM). The results of energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) analysis are presented. Research reveals the influence of chemical constitution of reactive atmosphere on the change of properties of nitrided layers.


2012 ◽  
Vol 452-453 ◽  
pp. 77-80 ◽  
Author(s):  
Shou Jun Wu ◽  
Gutmanas Elazar

In order to improve oxidation/erosion resistance of the T/P 24 steel components used in advanced power plants, chrome carbide coatings were prepared by PIRAC (Powder Immersion Reaction Assisted Coating) on T/P24 at 700-1000°C. Microstructure and phase composition of the obtained surface layers were characterized employing X-ray diffraction and scanning electron microscopy with chemical analysis (SEM/EDS). Results showed that homogenous smooth chrome carbide coatings can be formed on the substrate. Phase composition of the prepared coatings are differs with PIRAC temperatures. Prepared at lower temperatures or short times treatment, Cr23C6, Cr7C3 and Cr3C2 can be detected in the coatings. While, at higher temperatures or longer treatment times, Cr23C6 is subtotal phase of the produced coating. Moreover, the lower the PIRAC temperature is, the more of Cr7C3 and Cr3C2 are. Thermodynamics calculation based on Gibbs free energy is applied to explain phase composition difference of the coatings.


2012 ◽  
Vol 486 ◽  
pp. 309-312
Author(s):  
Rong Wu ◽  
Le Tian Tao ◽  
Ji Kang Jian

Mixed solvent of ethylenediamine (EDA) and ethylene glycol (EG) using MnCl4H2O, and (NH2)2CS as precursors was used to synthesize α-MnS micronsized architectures. Optimal α-MnS crystals were successfully grown from a mixed solvent of EDA:EG with a volume ratio of 1:1, reaction temperature of 140-180 °C and maintained for 6h. X-ray diffraction (XRD), scanning electron microscopy (SEM) was employed to characterize the structure and morphology of the product. The results show that the morphologies of α-MnS are found to be temperature dependent.


2014 ◽  
Vol 887-888 ◽  
pp. 384-387 ◽  
Author(s):  
Li Na Wang ◽  
Feng Hua Li ◽  
Meng Ge Dong ◽  
Ying Nan Li

The boronizing experiments on the surface of Ti-6Al-4V (TC4) titanium alloys were based on solid powder method. Different additives were added into the boronizing agent. The morphologies of surface layers on titanium alloys were observed in scanning electron microscopy (SEM). The phase compositions of boronized layers were analyzed by X-ray diffraction (XRD). The wear resistance properties of boronized TC4 were determined by the friction and wear testing machine. The results showed that all the boronized layers were composed of TiB2and TiB dual phases.When 5%Fe3O4was added into the boronizing agent, the boride layer contained more TiB2compound and was thicker than those with the addition of 5%Na2B4O7.


2013 ◽  
Vol 13 (1) ◽  
pp. 99-102 ◽  
Author(s):  
R. Mola

Abstract Al- and Al/Zn-enriched layers containing intermetallic phases were deposited on the Mg substrate by heating the Mg specimens in contact with the powdered materials in a vacuum furnace. The Al-enriched surface layers were produced using Al powder, whereas the Al/Znenriched layers were obtained from an 80 wt.% Al + 20 wt.% Zn powder mixture. The microstructure and composition of the layers were analyzed by optical microscopy, scanning electron microscopy and X-ray diffraction. The results showed that the Al-enriched layer comprised an Mg17Al12 intermetallic phase and a solid solution of Al in Mg. The layer obtained from the Al+Zn powder mixture was composed of Mg-Al-Zn intermetalic phases and a solid solution of Al and Zn in Mg. Adding 20% of Zn into the Al powder resulted in the formation of a considerably thicker layer. Moreover, the hardness of the surface layers was much higher than that of the Mg substrate.


2011 ◽  
Vol 679-680 ◽  
pp. 83-86
Author(s):  
James Huguenin-Love ◽  
Rodney J. Soukup ◽  
Ned J. Ianno ◽  
Noel T. Lauer

Thin SiC buffer layers have been grown by sputtering a graphite C target onto both (111) and (110) Si substrates. Converting the graphitic C into SiC is highly temperature dependent and relies on free silicon atoms that sublime from voids in the substrate at higher temperatures. Morphological and structural investigations were performed by Field Emission Scanning Electron Microscopy (FESEM) and X-ray Diffraction (XRD).


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


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