Makeieva H. Development of the technology fundamentals of rolling aluminum strips with steel net reinforcement for structural products with predicted mechanical properties

This thesis focuses on solving the scientific and technical problem, which is in the development of the technology of obtaining the aluminum composite reinforced with steel netting with the method of hot rolling by analysis of strain parameters of net cell elongation, wire elongation and wire ovalisation as well as the influence of these parameters on the mechanical properties and ability to absorb impact energy of the obtained composite. The well-known technologies of obtaining reinforced composites based on aluminum matrix were analyzed in this work, and the relevance of the reinforced aluminum composite creation was substantiated. The engineering method of calculating the strain parameters of the net between two aluminum strips after rolling was developed and the influence of the orientation of the reinforcing net between the layers of the matrix on the net cell deformation and the composite properties and the effect of reinforcement on the properties of the composite, in particular, on the achievement of calculated strengths, as well as on the ability of the composite to absorb the impact energy was experimentally investigated. The influence of the strain parameters on the net shape changes and on the mechanical properties of the reinforced composite was experimentally investigated. Three mechanisms of composite fractures were established during the tensile test. It was established that the simulation of the rolling process of the reinforced composite within the QForm software adequately represents the results of the experiment. The dependences of the reinforcing steel net deformation located between the aluminum strips, namely the lengthening of the entire composite, the transformation of the net cell, the lengthening and ovalization of the wire on the deformation degree during rolling, were established. The influence of thermal treatment after deformation processes on the properties of the composite and the anisotropy of the properties of the rolled composite compared with the results of mechanical properties measurements in the longitudinal and transverse directions were studied. Based on the results of the study, the technology foundations of rolling aluminum stripes with reinforced steel netting were developed to obtain a solid composite with increased mechanical properties. The results of the research were transferred for use to PrJSC Dniprovsky plant “ALYUMASH” and in the educational process at the Paderborn University and at the National Metallurgical Academy of Ukraine.