纳米金属间化合物NiAl的机械合金化合成及性能

MECHANICALLY SYNTHESIS AND MECHANICAL PROPERTIES OF NANOCRYSTALLINE INTERMETALLICS NiAl

利用机械合金化和高温热压工艺制备NiAl纳米晶体材料，并研究了材料的微观组织和力学性能，结果表明，NiAl的反应生成归结于机械碰撞诱发的爆炸反应机制.采用高温热压工艺可制备接近完全致密的纳米晶NiAl块体材料，NiAl纳米晶体材料的室温强度和塑性都高于铸态NiAl．纳米晶NiAl的高温强度依赖于应变速率。

Nanocrystalline NiAl has been synthesized by mechanical alloying elemental powders and hot pressing, its microstructure and mechanical properties have been investigated. The results show that the reaction mechanism of NiAl during milling can be attributed to explosive reaction induced by mechanical collision. Compacts of nanocrystalline NiAl with near full density have been achieved by hot pressing the drilled powder. The nanocrystalline NiAl material is much strong and ductile over cast and extruded NiAl at room temperature. Yield strength of the nanocrystalline NiAl at high temperature is dependent on strain rate, and deformation is considered to be controlled by diffusion mechanism.