ВПЛИВ ОБРОБКИ ПОВЕРХНІ ЗА ТЕХНОЛОГІЄЮ SMAT НА МЕХАНІЧНІ ВЛАСТИВОСТІ ПОВЕРХНЕВИХ ШАРІВ МІДІ

Abstract

Nanostructured materials are characterized by a specific structure compared to polycrystalline materials. Nanostructured materials are created in way of strong deformations. SMAT (surface mechanical attrition treatment) technology consists in the treatment of the surface of a material with steel balls accelerated by a generator of high-frequency oscillations (about 20 kHz). This changes the mechanical properties of the materials. The size of graines in such materials decreases in the direction from the volume of the crystal to the surface. As a result of SMAT processing, graines become nanosized near the surface of the samples. Such materials have a large number of subsurface defects formed as a result of intense plastic deformation, which determines their thermodynamic and diffusion characteristics. The purpose of this work is to develop the device of high-frequency (20 kHz) surface machining by attrition using SMAT technology and its application to the treatment of surfaces, both polished copper plates and electrodeposited in a stationary mode to copper plates with copper layers. In this work, the device is developed and the technology of high-frequency mechanical surface treatment of SMAT is described. The design features and technical characteristics of the experimental plant are presented. In the work, the surfaces of copper substrates were processed by different methods: grinding and polishing of copper polycrystalline plates, electrolytic deposition of copper surface layers on these plates, processing of prototypes by SMAT technology. The microhardness was measured in the surface layers of the linings made using different technologies and their comparative characteristics were performed. It is established that high-frequency surface treatment of plates by SMAT technology increases the microhardness of the surface of copper plates of different types, both polished and with electrolytically deposited copper. The results of the research showed that the sample, which was subjected to electrolytic deposition of copper, has a high defectiveness of the surface and reduced microhardness. After processing such a sample using SMAT technology, it is obtained a hardness higher than the reference polycrystalline copper sample.