Electron Irradiation Induced Phase Transformation in Nd₂Fe₁₄B Alloy

Abstract

Transformation and change in the microstructure of Nd₂Fe₁₄B compound under electron irradiation were examined. The Nd₂Fe₁₄B compound did not maintain its original structure under electron irradiation and was transformed to an amorphous phase through solid-state amorphization. With further electron irradiation, crystallization of the amorphous phase occurred forming a nano-crystalline structure. The phase selection of electron irradiation induced crystallization depended strongly on the irradiation temperature; nanocrystalline α-Fe phase precipitated in the amorphous phase at 104 K, while a nanoduplex structure composed of α-Fe, compounds and residual amorphous phase was formed at 298 K. Electron irradiation induced phase transformation is a very effective method to control the nanocrystalline structure in Fe-Nd-B alloy.