Improved Hardness and Toughness of AlMgB_(14) Composites Through Addition of Reinforcement Phases

摘要

Toughening of ultra-hard AlMgB_(14) was explored through the addition of second phase reinforcements. The high hardness of AlMgB_(14) combined with its low chemical reactivity with titanium and other metallic alloys makes these materials promising for high-speed machining, coatings, and other wear-resistant applications. However, actual performance to date has suffered as a result of low toughness. Initial machining and wear tests have had encouraging results and optimization of composition and microstructure of these composites is expected to result in additional performance benefits. High-energy milling was used to produce sub-micron powders that were consolidated into composites, some of which exhibited a maximum hardness of 46 GPa. Additions of TiB_2 have increased hardness, toughness, and erosion resistance. Improvements in fracture toughness will expand the array of possible applications for this material.