Effect of Cold Rolling and Annealing on the Microstructure and Texture of Erbium Metal.

Zongan Li,Daogao Wu,Minglei Xu,Xiaowei Zhang,Wenli Lu,Yixuan Wang,Ning Mao,Zhiqiang Wang,Dehong Chen,Wensheng Yang,Jinying Li,Shiying Chen,Shuang Wang

doi:10.3390/ma15041370

Abstract

Erbium metal with purity ≥ 99% was cold rolled to 30%, 40%, 50%, and 60% deformations and the Er metal of 60% deformation was annealed at different temperatures for 1 h. The effect of cold rolling deformation and annealing on the microstructure and texture evolution of Er metal was investigated by XRD, EBSD, Microhardness tester, and OM. P is the orientation index, which is used to judge the preferred orientation. The research results showed that grains were broken and refined gradually with increasing deformation, the average grain size was 3.37 µm, and the orientation distribution was uniform for 60% deformation; deformation twins appeared in the grain when the deformation was less than 40%, which contributed to the generation of (0001) plane orientation. Comparing with the initial state, the (010) plane orientation gradually weakened and the (110) plane orientation had a trend of further strengthening with the increasing deformation; the (20) plane orientation remained unchanged, but there was a gradual weakening trend when the deformation was greater than 50%. For 60% deformation of Er metal, the deformed microstructure was replaced by fine equiaxed grains with the increasing annealing temperature, and the high-performance Er metal with fine and uniform equiaxed grains can be obtained under annealing at 740 °C for 1 h.

Highlights

In recent years, rare earth oxide films have received widespread attention due to their high dielectric constant, large band gap width, and good thermal stability [1]
Er2O3 film is an ideal candidate for high dielectric materials and has a strong competitiveness in the new generation of metal oxide semiconductor field effect transistor (MOSFET) gate dielectrics [2–4]
Er2O3 thin film can be applied to optical devices, tritium permeation barrier (TPB), and hydrogen storage [5,6]

Summary

Introduction

Rare earth oxide films have received widespread attention due to their high dielectric constant, large band gap width, and good thermal stability [1]. Er2O3 film is an ideal candidate for high dielectric materials and has a strong competitiveness in the new generation of metal oxide semiconductor field effect transistor (MOSFET) gate dielectrics [2–4]. Erbium (Er) thin film is an ideal neutron generator for tritium target material in nuclear industry [7–9]. It is necessary to obtain high-quality sputtering Er target with high purity, fine grain, uniform structure, and preferred orientation. As-cast Er metal can’t satisfy the specifications of industrial sputtering targets, the grains usually need to be refined and crystal orientation should be optimized by Materials 2022, 15, x FOR PEER REVIEW rolling and annealing.

ND RD

Orientation Index

Findings

Conclusions