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•A new approach allows to evaluate the suitability of recycled carbon fibers as a reinforcing filler of plastics for additive technologies.•Recycled carbon fibers with clean surface ...from CFRP waste.•Suitability evaluation of reclaimed short carbon fibers for additive technologies.
This article presents a new approach to suitability assessment of short reclaimed carbon fiber (rCF) for additive technologies via commonly used analytical methods. Acrylonitrile butadiene styrene (ABS) based plastics reinforced with virgin or recycled CF samples were received, their mechanical properties and morphology of tensile fractured surface were determined by SEM (Scanning Electron Microscopy) and tensile strength test. As long as operating characteristics of CFRP are affected by single fiber strength as well as adhesion (interfacial interaction) between matrix and CF, this research also includes investigation of fiber surface with Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray diffraction (XRD). Correlation between suggested complex parameters of investigated CF and strength of plastics (CFRP) samples was shown. It was also established that contribution of each investigated parameter is additive.
The main goal of the article is to describe the development and production of a prototype of an additional system for wheel motor bearing protection using additive technologies. These technologies ...include rapid prototyping and vacuum casting. These technologies greatly facilitate and speed up the whole process of developing a new component. Before the development itself, it was necessary to digitize the wheel hub using reverse engineering technology. Using a 3D scanner, a part model was created, based on which an additional system for wheel bearing protection was designed for the CAD system. The dimensional analysis of the produced prototypes was performed. Prototypes of the protection system made of different materials will be tested in common operation conditions.
Currently, additive technologies, in particular, electric arc growth as the most universal and productive, are used to produce individual machine parts. The problem of studying the process of ...structure formation in alloys during electric arc additive growth to ensure the necessary parameters of the microstructure of a material and its mechanical properties is challenging. 09G2S steel samples for research are fabricated on a developed test bench implementing the technology of 3D printing by electric arc surfacing, microstructural studies on an optical microscope are used, and microhardness measurements are carried out. The features of structure formation in a 09G2S alloy during additive electric arc growth have been determined, and controlled parameters have been identified to ensure the necessary parameters of the structure and, consequently, the mechanical properties of the alloy. The heat input of the surfacing process and the temperature of a thermal cycle are found to play a significant role in the structure formation in the material. The conducted research and established dependences make it possible to control the structural state of 09G2S steel during cladding to ensure the required parameters of its microstructure and mechanical properties.
Abstract
It is exists the problem of big product manufacturing with minimal dimensions tolerances. To solve this problem it is necessary to compensate the deformations influence. In researching of ...method, it became clear that deformation degree has changed and depended on size and form of part. However, the amount of deformation degree to dimension of part is still independent of size. This fact has observed after production of axis-symmetrical parts. The simple axis-symmetrical part was built up. The dimensions of part was measured, and the compensation coefficient was calculated. The dimensions of part was scaled on this coefficient for compensation of shrinkage effect. After that the experiment was repeated.
The supercharger is intended for heating a fluid (gaseous helium or gaseous nitrogen) used for the pressurization of fuel tanks of oxidizer and propellant of a rocket engine. The fluid is heated with ...the generator gas downstream the turbine. A supercharger with increased channel surface roughness was made according to an additive technology. High roughness is one of the features of producing parts by selective laser melting. The article presents a method of calculating the heat transfer of generator gas and nitrogen, as well as the results of heat transfer both with and without account of the surface roughness in the channels of the liquid-propellant engines additively manufactured supercharger. Firing tests were carried out at the research base of NPO Energomash JSC. The calculated and experimental values of the temperature of the working medium at the outlet of the supercharger are compared.
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