High Pressure Sintering of Aluminum-Matrix Composites Modified with Shungite Carbon and Corundum

摘要

In this paper the structure of aluminum alloys modified with additives of nanosructured shungite carbon or ultradispersed corundum after heat treatment under high pressure was investigated. In order to increase the chemical affinity for aluminum matrix the chemical heat treatment of shungite powder and corundum in the environment of aluminum chloride prior to high pressure sintering was performed. As a result Al-coated additives such as Al-shungite and Al-Al_2O_3 were obtained. Structural studies of Al-modified additives was revealed that shungite based additive represents the conglomerates ranging from a few to several tens of microns in size, alumina based additive consist of the particles from 0.4 to 0.6 microns in size. It has been shown that the introduction of additives of nanosructured shungite carbon or ultradispersed corundum with aluminum coating in aluminum matrix inhibits growth of the aluminum grains in the high temperature sintering region and increases microhardness of the composite materials. The technological schemes of high pressure sintering of aluminum-matrix composites such as Al-shungite and Al-Al_2O_3 have been developed.