THERMOPHYSICAL PROPERTIES OF β-SiC/Al COMPOSITES

Research in such high-tech fields as aerospace and defense industries, with the active use of high-precision inertial tools, has reached a stage where the main requirements are maximum measurement accuracy and minimum mass. The two main indicators for improving the design of materials for tool engineering are the harmonious thermophysical properties and high dimensional stability. Currently, particle-reinforced aluminum matrix composites are actively being studied, with the main focus being on the volume fraction of particles, their size, interfacial bonds, and other aspects. In this work, β-SiC/Al composites with a volume fraction of 45% were obtained by pressure impregnation, taking into account the strict requirements for materials for tool engineering. The microstructure and thermophysical properties of β-SiC/Al composites were studied using a dilatometer and a laser pulse thermal conductivity analyzer. An analysis of the influence of various factors on these properties was performed. The average coefficient of thermal expansion of β-SiC/2024Al composites with an average nominal particle size of 5 microns in the temperature range from 20 to 100^оC is 11,32×10^–6 1/К. This value is among the values calculated using the Turner and Kerner mo dels and is lower than that of α-SiC/2024Al composites with the same particle size. The thermal conductivity of β-SiC/2024Al composites with a particle size of 3.5 and 5 microns is 120 and 132 W/(m^.K), respectively. These values are higher than those of α-SiC/2024Al composites with the same particle size. The thermal conductivity of β-SiC/2024Al composites increases with increasing particle size. In comparison with α-SiC/Al composites, β-SiC/Al composites open up new prospects for the development of composite materials intended for tool engineering.