HIGH TEMPERATURE MATERIALS AND PROCESSES, cilt.27, sa.4, ss.243-248, 2008 (SCI-Expanded)
The properties of ceramic-metal (cermet) composites as tensile strength, hardness and resistance to corrosion are superior to individual ceramics and metals. Especially, high temperature mechanical property of a composite material and its stability are very important for specific usages. On the other hand, the use of a composite material is limited by inadequate mechanical properties at high temperatures, large thermal expansion and fast oxidation. Besides, thermal expansion obviously impairs thermal shock strength. In this study, a composite material with dimensional stability and high oxidation strength, which preserves main mechanical properties at high temperatures, was produced. Anhydrous boron oxide was chosen as reinforcement due to its light weight, high melting point, limited thermal expansion and fire retardant property. As a matrix, zinc was used owing to its low density, low melting point, low cost and high corrosion resistance. For this purpose, zinc and anhydrous boron oxide powders were mixed in an attritor at 600 rpm and sintered at temperatures determined from the TGA-DSC analyses. The obtained composites were characterized by mechanical, microstructural and thermal expansion tests.