STRUCTURE AND PROPERTIES OF COPPER MATRIX NANOSTRUCTURED COMPOSITE MATERIAL OBTAINED BY MECHANICAL ALLOYING
By the structural materials used in rocket for the manufacture of "hot machines" (combustion chambers, gas generators, heat exchangers), meet high requirements on the thermal conductivity, heat resistance and heat resistance. Currently, the specified requirements are met by heat-resistant bronze in combination with the thermal barrier coating, for example alloys Narloy Z, bronze or BrHTsrT BrH08 that provide heat flux to eat 36×106 kcal / m2chas. For developed new rocket engine needs a new structural material with high thermal conductivity while maintaining its mechanical properties. The most promising material is pure copper, with the introduction in its metal matrix carbon nanoparticles (nanotubes, fullerenes), which can significantly increase the heat resistance. This article describes in detail the first technology of obtaining, structure and properties of the composite with a mass fraction of 0.5% CNTs obtained by mechanical alloying. For comparison, the properties of the sample of copper powder ICP-1 without the addition of carbon nanoparticles. For mechanical alloying using a planetary mill "pulverisette 5» (FRITSCH). doping process was carried out for 30 minutes while heating took place capsules with the composition to 60-80 ° C. Next, heat treatment was performed in a vacuum, and annealing the composition. Pre-compression was carried out in a steel capsule force of 100 ton, cylindrical preform was obtained as a result. It was further held hot isostatic pressing (HIP) in gazostat QVINTUS-250. For mechanical testing the samples were fabricated with cylindrical working portion 5 mm thick. The results of strength tests have shown that the limit of the composite strength after HIP at ~ 11% higher than in sample ICP-1 (non-alloy particles) and 2 times higher than the yield strength of the M2 brand copper. The thermal conductivity of the composite sample of the test was 289 W / m • K, which is ~ 20% higher than the thermal conductivity of the traditionally used BrH08 bronze (239 W / m • K). These results demonstrate the fundamental possibility of producing a copper composite material reinforced with nano-sized particles of carbon - CNT by mechanical alloying, however, there is need to clarify the technology of its receipt