Nitrogen sorption tests, SEM-windowless EDS and XRD analysis of mechanically alloyed nanocrystalline getter materials

Nanostructured Materials Pub Date : 1999-09-01 DOI:10.1016/S0965-9773(99)00372-4

G. Valdrè , D. Zacchini , R. Berti , A. Costa , A. Alessandrini , P. Zucchetti , U. Valdrè

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引用次数: 21

Abstract

Gas absorbing materials (getters) find several applications in modern vacuum technology; in particular to maintain required vacuum levels in evacuated and sealed enclosures. The gas absorbing properties of these getters depend on the physico-chemical nature of their surfaces. The aim of this work is to study the absorption properties of commercial Zr-based alloys (non-evaporable getters) after mechanical alloying by means of a high vacuum planetary ball milling equipped with an in-situ compaction facility. The main aim was to refine the grain size and to develop particular defect structures to enhance the getter properties. The results have shown an improvement of the specific pumping speed of the ball milled commercial Zr-Zr(V,Fe)₂ alloy with respect to the starting microcrystalline material. In particular, under our experimental conditions, the specific pumping speed vs absorbed gas curve presents a maximum after 2 hours of milling; prolonged milling reduced the pumping speed of the alloyed material. This behaviour is explained in terms of two opposing simultaneous chemical and structural effects.

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机械合金化纳米晶吸气剂材料的氮吸附试验、sem -无窗EDS和XRD分析

吸气材料在现代真空技术中有多种应用;特别是在真空和密封外壳中保持所需的真空水平。这些吸附剂的气体吸收性能取决于其表面的物理化学性质。本工作的目的是研究商业zr基合金(不可蒸发吸收剂)在机械合金化后的吸收性能，采用高真空行星球磨配备原位压实设备。主要目的是细化晶粒尺寸和发展特定的缺陷结构，以提高吸气剂的性能。结果表明，球磨后的Zr-Zr(V,Fe)2合金的比抽速相对于初始微晶材料有所提高。特别是在我们的实验条件下，在铣削2小时后，比抽速与吸收气体的曲线达到最大值;长时间铣削降低了合金材料的抽运速度。这种行为可以用同时发生的两种相反的化学和结构效应来解释。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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Nanostructured Materials

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