Speaker
Description
Polytetrafluoroethylene (PTFE) is a synthetic thermoplastic polymer that significantly outperforms other polymer materials in terms of its anti-friction properties. Despite its advantages, polytetrafluoroethylene also has a number of disadvantages, such as a high thermal expansion coefficient and low mechanical strength. One promising way to overcome these disadvantages is to introduce various fillers into PTFE that comprehensively improve the properties of the polymer. The optimal set of properties is determined by the choice of filler based on its dispersion, surface topology, filler-to-polymer ratio, the technology used to mix the filler with the polymer, and the technology used to process the resulting composition into a product. Microhardness measurements have long been used as a method for microprobing the mechanical response of various materials and their compounds. Performing a series of microhardness measurements along a given line or on a given area on the surface of a sample allows for the development of a method for mapping or profiling of mechanical properties. Therefore, the aim of this work was to use a non-destructive instrumental indentation method to develop a microhardness profiling method for determining the effect of filler on the mechanical characteristics of a composite material. Nickel and silicon carbide particles were used as fillers for PTFE compositions in this work. The fillers were introduced into the fluoroplastic both separately and in various combinations, depending on the purpose of the compositions. The microhardness of the obtained materials was measured using the kinetic hardness method with a Micron-Gamma device, which allows simultaneous recording of the indenter penetration depth and load. The studies were conducted at loads ranging from 30 to 200 g according to the indenter loading-unloading scheme (without a pause between cycles). The change in microhardness was determined at different and constant loads on the indenter, depending on the indentation location. Graphs of the dependence of microhardness and Young's modulus on the load on the indenter were obtained. The study of the mechanical characteristics of composite materials, such as microhardness and Young's modulus, makes it possible to formulate a scientifically sound approach to predicting and targeting the properties of such composites.
| Type of presence | Presence at Taras Shevchenko National University |
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