Effect of aggressive media on working capacity of composite elements in mechanical engineering

Abstract

Abstract Composite elements can improve not only the strength but also the protective properties of engineering products, thus reducing corrosion losses. At present, there is no sufficient study of the environment influence on the working capacity of composite elements, in particular on the decrease of their crack resistance. The article discusses the calculation and experimental methodology, which allows increasing the accuracy and reliability of the assessment of crack resistance of composite elements under the influence of aggressive media. The presented methodology can be implemented without a test facility by testing directly experimental specimens. To determine the magnitude of the crack propagation energy, a mathematical model is proposed that includes only one independent parameter (radius of curvature). The authors investigated qualitative and quantitative characteristics of the effect on the fracture toughness of such aggressive media as machine oil and water. It is shown that the effect of air and machine oil on the crack resistance is approximately the same. A decrease in crack resistance by 1.56-11.1 times is observed under the influence of water. The composite elements based on the VAK-A adhesive composition have the highest crack resistance in aggressive media.