Forming a defective surface layer when cutting parts made from carbon-carbon and carbon-polymeric composites
Journal Title: Восточно-Европейский журнал передовых технологий - Year 2018, Vol 4, Issue 1
Abstract
<p class="papertitle">We report results of theoretical and experimental research aimed at establishing the mechanisms for the formation of a defective layer at the machined surfaces made from carbon composite materials, specifically those from carbon-carbon and carbon-polymeric groups. Possessing a set of unique physical and mechanical properties, the latter are increasingly applied in aviation and space technologies. However, since the properties of a material are predetermined not only by the components applied but also by the processes to obtain products (laying of reinforcing fibers, orientation of threads), conducting mechanical tests of samples-witnesses is a compulsory stage in the operations performed.</p><p class="papertitle">Based on the generalization of statistical and theoretical-analytical information, we have developed a model of the emergence and propagation of cracks in a quasi-fragile material, particularly the carbon-carbon and carbon-polymeric composites, caused by the action of a cutting wedge. It is shown that the stresses that occur in a surface layer predetermine the intensity of crack growth while a direction of microcracks propagation is due to the applied force load. Therefore, control over the direction of force action, as well as the application of certain technical means, including a hydroabrasive jet, could enable the localization of microcracks in small quantities at the surface of the formed edge.</p><p class="papertitle">The established regularities in the formation of a defective layer at machining (including the hydroabrasive cutting) have made it possible to identify ways to improve the quality of a sample and to reduce the layer thickness to 0.05 mm. The derived dependences of the destruction zone parameters on the stresses that occur at cutting allowed us to obtain the rational sequence of machining transitions, at which the defective surface layer is the smallest.</p><p class="1">The results obtained provide a possibility to significantly increase the accuracy of mechanical tests of carbon composite materials, thereby reducing the variance in the measurements of controlled parameters by 30‒40 %.</p><p class="papertitle">The results have been actually implemented industrailly, and are of interest for the further research aimed at the hybridization of processes, as well as the development of technologies based on a functional-oriented approach.</p>
Authors and Affiliations
Alexandr Salenko, Olga Chencheva, Evgeny Lashko, Viktor Shchetynin, Sergey Klimenko, Irina Gusarova
Keywords
Related Articles
- EP ID EP528051
- DOI 10.15587/1729-4061.2018.139556
- Views 33
- Downloads 0
Development оf combined method for predicting the process of the occurrence of emergencies of natural character
<p>We developed a combined method for forecasting of the process of occurrence of emergency situations of a natural character. In contrast with other methods, it makes it possible to perform a complex forecasting of emer...
Development of a renewable hybrid power plant with extended utilization of pumped storage unit equipment
<p>The scheme of a renewable hybrid power plant with the extended use of the installed equipment of the pumped storage unit for the conversion of the photovoltaic and wind generators direct current to the alternating one...
Plasmochemical preparation of silver nanoparticles: thermodynamics and kinetics analysis of the process
<p>The thermodynamics and kinetics analysis of the plasmochemical formation of silver nanoparticles is performed. The thermodynamics analysis is made on the basis of calculation of the Gibbs free energy of formation of s...
Analysis of conditions for the propagation of internal waves in a threelayer finitedepth liquid
<p>The problem of propagation of internal waves for an ideal incompressible fluid was considered. The hydrodynamic system consisted of three layers of a finite thickness that did not mix and were bounded with a solid cov...
ESTIMATION OF FIRE PROTECTION EFFICIENCY OF ARTICLES MADE FROM REED UNDER AN EXTERNAL ACTION OF GASOLINE FLAME
Our study into the process of reed ignition has established the mechanisms of heat transfer to a material, which makes it possible to influence this process. It has been proven that the process of ignition implies heatin...