多道次轧制变形量对高纯钽靶坯微观结构与力学性能的影响

Microstructure and Mechanical Property of High-Purity Tantalum Target Billets with Multi-pass Rolling Reduction

摘要:

为获得晶粒尺寸均匀性可控、织构取向可调且硬度合适的高纯钽靶坯，采用电子束熔炼-轧制-退火工艺制备了系列样品，探究了轧制模式（冷轧/热轧）、多道次轧制变形量梯度对钽靶坯微观组织与力学性能调控规律。结果表明，冷轧工艺可有效细化晶粒，其晶粒均匀性显著优于热轧工艺。在冷轧条件下，随着冷轧变形量从20%递减至2%，钽靶坯平均晶粒尺寸从46.01 μm变化至58.92 μm，其中(100)晶面和(111)晶面占比逐渐上升，而晶面(110)占比呈快速下滑趋势。当冷轧变形量为2%时，钽靶坯样品中(110)晶面生长得到一定抑制，获得了高占比的(100)-(111)混合随机织构，使得钽靶坯的硬度增加至147.68 HV。这一研究结果为研制高质量钽溅射靶材提供参考。

Abstract:

To fabricate high-purity tantalum target billets with uniform grain size, preferential orientation, and homogeneous hardness distribution, a series of high-purity tantalum target billets were prepared by electron beam melting and multi-pass rolling technique. The effects of rolling modes (cold rolling/hot rolling) and multi-pass rolling reduction on the microstructure, and mechanical properties of tantalum target billets were investigated. The results indicate that compared with that prepared by hot rolling, the sample prepared by cold rolling exhibits smaller and more uniform grain size. Under cold rolling condition, the multi-pass rolling reduction decreases from 20% to 2%, and the grain size and standard deviation of the tantalum target billets change significantly, varying from 46.01 μm to 58.92 μm. Meanwhile, the proportion of (100) and (111) crystal planes gradually increase, while the proportion of (110) crystal plane rapidly decreases. When the multi-pass rolling reduction is 2%, the growth of the (110) crystal plane in the tantalum target blank sample is certainly inhibited, a high proportion of (100)-(111) mixed random texture is obtained, and the Vickers hardness of the tantalum target increases to 147.68 HV. These research findings provide an important reference for the development of high-quality tantalum target billets.