Nanocrystalline Al Composites from Powder Milled under Ammonia Gas Flow

作者:Cintas J*; Caballero E S; Montes J M; Cuevas F G; Arevalo C
来源:Advances in Materials Science and Engineering, 2014, 2014: 617241.
DOI:10.1155/2014/617241

摘要

The production of high hardness and thermally stable nanocrystalline aluminium composites is described. Al powder was milled at room temperature in an ammonia flow for a period of less than 5 h. NH3 dissociation during milling provokes the absorption, at a high rate, of nitrogen into aluminium, hardening it by forming a solid solution. Controlled amounts of AlN and Al5O6N are formed during the subsequent sintering of milled powders for consolidation. The pinning action of these abundant dispersoids highly restrains aluminium grain growth during heating. The mean size of the Al grains remains below 45 nm and even after the milled powder is sintered at 650 degrees C for 1 h.

  • 出版日期2014