PSI - Issue 2_B

S.V. Astafurov et al. / Procedia Structural Integrity 2 (2016) 2214–2221

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S.V. Astafurov et al. / Structural Integrity Procedia 00 (2016) 000–000

3. Conclusions The simulation results showed significantly limited possibilities of the cohesive interface model to describe the influence of the properties of the interfaces on the mechanical properties of the composite material at the micro level. In particular, the variation of strength parameters of the interface influences on the strength and fracture character of composites only in the range of low values of adhesion strength (which is not greater than the strength of the ceramic phase). In this case ability to control the rheological properties of the composite is absent. As evidenced by the results of a computer-aided simulation, an effective tool for analyzing capabilities to control rheological properties of the composite by means of changing of the characteristics of the interphase areas are models of extended interface zones. Thus, the models of homogeneous interface zones provide the opportunity to study influence of thermal conditions of composite material production and difference between the elastic constants and rheological parameters of different phases on integral properties and strength of material. In particular, using this model, it is shown that the leading role in strengthening of metal-ceramic composite with “wide” interfaces belongs to the “initial” geometrically necessary dislocations generated in the process of its synthesis. In cases where the interphase interfaces are characterized by gradients of elemental composition, defects and as a result, of the mechanical properties at the transition from the ceramic inclusions to metallic binder, is the most adequate “gradient” model of the interface zone. The characteristic difference of this model from the previous is accounting of changing of the concentration of defects, impurities and nanoparticles in the transition from the surface of the ceramic inclusion to binder. Simulation results showed that the distribution of stress and strain and consequently strength and fracture toughness of metal- ceramic composites are determined not only by the degree of hardening, but to a lesser extent by the magnitude of the gradient of the mechanical properties in the interface. Acknowledgements This work was supported by the RF Ministry of Education in the framework of the federal target program “Research and developments on priority directions of scientific-technological complex of Russia for 2014-2020” (Agreement 14.613.21.0049 November 11, 2015, project ID RFMEFI61315X0049). References Chawla, N., Chawla, K.K., 2006. Metal matrix composites. Springer, New York, pp 401. Lurie, S., Belov, P., Volkov-Bogorodsky, D. Tuchkova, N., 2006. Interphase layer theory and application in the mechanics of composite materials. Journal of Materials Science 41, 6693-6707. Singh, G., Yu, Y., Ernst, F., Raj, R., 2007. Shear strength and sliding at a metal-ceramic (aluminium-spinel) interface at ambient and elevated temperatures. Acta Materialia 55, 3049-3057. Tran, K.N., Ding, Y., Gear, J.A., 2010. Finite element modelling of the interphase region on the mechanical behavior of a composite containing micrometer sized spherical particles. ANZIAM Journal 51, 16-31. Suh, Y.S., Joshi, S.P., Ramesh, K.T., 2009. An enhanced continuum model for size-dependent strengthening and failure of particle-reinforced composites. Acta Materialia 57, 5848-5861. Shao, J.C., Xiao, B.L., Wang, Q.Z., Ma, Z.Y., Yang K., 2011. An enhanced FEM model for particle size dependent flow strengthening and interface damage in particle reinforced metal matrix composite. Composites Science and Technology 71, 39-45. Psakhie, S.G., Shilko, E.V., Smolin, A.Yu, Dimaki, A.V., Dmitriev, A.I., Konovalenko, Ig.S., Astafurov, S.V., Zavsek, S., 2011. Approach to simulation deformation and fracture of hierarchically organized heterogeneous media, including contrast media. Physical Mesomechanics 14(5-6), 224-248. Psakhie, S., Shilko, E., Smolin, A., Astafurov, S., Ovcharenko, V., 2013. Development of a formalism of movable cellular automaton method for numerical modeling of fracture of heterogeneous elastic-plastic materials. Fracture and Structural Integrity 24, 26-59. Shilko, E.V., Psakhie, S.G., Schmauder, S., Popov, V.L., Astafurov, S.V., Smolin, A.Yu., 2015. Overcoming the limitations of distinct element method for multiscale modeling of materials with multimodal internal structure. Computational Materials Science 102, 267-285.