Papers by Keyword: Spectrometry

Abstract: Wear particle analysis as a nondestructive evaluation technique is an effective method to determine the lubricating oil conditions within different lubricated machines, thus monitoring wear modes and imminent failures in these machines, such as gear-boxes and engines. Ferrographic analysis of wear particles in lubricating oil could give complete information about ferrous and non-ferrous solid debris present in the oil sample. Spectrometric oil analysis could give a direct measure of elemental metal content in the oil such as Iron, Aluminum, Lead and Cupper. These techniques provide cheap, fast and easy methods to use predictive maintenance methods which can replace other conventional methods. The objective of the present study is to apply wear particle analysis technique for condition monitoring of an industrial gear-box transmission over two year’s period of time. This gear-box belongs to one of the machines of the Oriental Weavers Company (OWC), one of the largest carpet manufacturers in the world. Spectrometric and ferrographic analysis were used where quantitative and qualitative changes in the concentration and size distribution of different particles were analyzed and compared to baseline values.

Abstract: The selective laser sintering is a technique used to quickly fabricate a scale model of a physical part or assembly using three-dimensional computer aided design CAD data. This technique is used to obtain complex pieces in different domains like machine building industry, automotive industry, foundry and medicine. The selective laser sintering process is used to obtain different prototypes, medical instruments or personalized implants in medicine. The powders used to obtain the medical instruments and for implants must to be very resistant to corrosion, non-toxic and present good fatigue resistance. The powders used are in generally, stainless steel, alloy titan TA6V, alloy Co-Cr and different polyamides.

Abstract: . The paper present aspects about the obtaining of non-precious dental alloys (type CoCrMo and CoCrMoSi7), the determination of chemical composition by optical emission spectrometry and the experimental tests for determining the tensile strength, made on standard plate samples. The base material used in experiments was a commercial alloy, from CoCrMo system, which belongs to the class of dental non-precious alloys, intended to medical applications. The obtaining of studied alloy was made on arc re-melting installation, under vacuum, type MRF ABJ 900. The process followed to realize a rapid melting, with a maximum admissible current intensity. The samples for tests were obtained by casting in an electric arc furnace, under vacuum, in optimal conditions for melting and solidification and processing by electro-erosion, to eliminate all the disturbing factors which come by processing conditions for the samples. The determination of chemical composition for cobalt based alloys, by optical emission spectrometry, was made on SpectromaxX equipment with spark. The electrical discharge is made with the elimination of an energy quantity, fact which determine plasma forming and light issue. Tensile tests for standard samples, made from cobalt based alloy, was made on Instron 3382 testing machine, and assisted by computer. The obtained results are: elongation, elasticity modulus, tensile strength and offer complete information about the analyzed mechanical properties. For the certitude of obtained experimental results, the tests were made on samples with specific dimensions according ISO 6892-1:2009(E) standard, both for the tensile strength, and also machine operation.

Abstract: Compared with normal reflecting scanning transform Spectrometry, cube-based Spectrometr is a key component in the time-based modulation interference spectrometer, it have more compact structure ,using less accessory , easy to fix up , more steadily and more practicality . Calculations on optical path difference (OPD) of spectrometry play an important role in analyzing and improving of the structure. Following the law of Malus and the geometrical relationship of model, get the formula of OPD and the affective factors .The calculation results demonstrate that OPD is closely related to the tilted angel of rotating reflector , the size of cube reflector and the refractive index of reflector. And this kind of spectrometry has the character of high resolution, especial in some spectrum.

Abstract: The specific properties of material, such as resistance, the cost and the weight, become key factors in the decision making and the choice of vulgarization of material in its industrial and technological aspect. The choice of a resinous system used like stamps in the design of composites, depends on the mechanical performances and the cost of the resin. Currently the prohibitory cost of composite materials slows down the rise of their applications in certain technical fields. In this study, the physical and the mechanical characterization is presented, bearing on the resin of the type RESOW 55 E reinforced out of powders of different nature at different rate. The results of the mechanical tests carried out, show clearly, that the fracture is strongly influenced by the type and the rate of powder added in the matrix. In reinforcement, according to the results obtained with x-rays, one notes that there are no new chemical compounds formed in elaborate materials. The presence of powder does not modify the structure of polymer and that is confirmed by the x-rays analysis and spectrometric analysis. Based on experimental results, a model of Weibull strength distribution function has been established for each specimen. Finally, a confrontation of the theoretical and experimental results is carried out, based on probabilistic models.

Abstract: In modern sciences and technologies it is required to investigate local atomic and electron structure of matter independently on its aggregate state. There are advanced methods aimed at short order. These methods are based on the phenomena accompanied by interference of secondary electrons excited by primary X-ray radiation. Such methods are known as XAFS (X-ray absorption fine structure). These methods are based mainly on using of synchrotron radiation. It is realized in two modes: ‘transmission mode’ and registration of secondary effects that follow the primary X-ray absorption. One may announce only two such effects: X-ray induced fluorescence and X-ray induced electron emission (photoeffect). However, the access to synchrotron rings is problematic for the most users. This fact supposes the necessity to develop laboratory devices of direct urgent access. Since the power of laboratory X-ray sources is much less than the flux from synchrotrons, it is necessary to use secondary electron detectors of considerably higher efficiency. Moreover, it is attractive to possess energy in spatial resolution. Channeltrons and multi-channel plates do not have such abilities. That is why the advanced electron detector was developed and exposed to photoeffect under acceleration field. The work is performed within the frames of ISTC Project #3157.