2014-Sustainable Industrial Processing Summit
SIPS 2014 Volume 6: Rare Earths & Ionic Liquids
| Editors: | Kongoli F |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2014 |
| Pages: | 432 pages |
| ISBN: | 978-1-987820-08-9 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Nanocrystalline Metals and Alloys of Platinum Group with Nanoscale Porosity
Inna Popov1;1THE HEBREW UNIVERSITY OF JERUSALEM, Jerusalem, Israel;
Type of Paper: Regular
Id Paper: 86
Topic: 9
Abstract:
In this talk, we present a new class of stable metallic nanostructural materials combining nanoscale porosity and nanoscale crystallinity. We report a low temperature chemical synthetic way enabling preparation of stable nanostructural metals and their alloys.
Based on numerous examples of pure metals and binary alloys of platinum group, we show that the proposed route provides tight control over morphology (down to nanometer scale), chemical composition (ratio of metallic elements) and phase composition of final metallic material. We found that the crystallite size of an alloy/metal and the smallest size of a pore are both affected not only by a preparation temperature, but also by a number of coexisting crystalline phases. The phase composition of binary alloys is very close to the thermodynamic equilibrium for eutectic and peritectic-type systems (Rh-Ru, Ir-Pt, Ir-Ru, Ru-Pt). The unique porous structure of the presented new metals is composed of interconnected nanoscale metal ligaments interpenetrating with the pores whose size ranges from a few microns down to a few nanometers. The free volume occupies more than 90% of the total material volume. Pores and metal ligaments exhibited obvious features of self-similarity over the whole observed structural size range. To sum up, with the characterization data obtained at the presented new materials, we can discuss their possible applications for fundamental and research purposes. We will also discuss the expected implications of a proposed preparation path which, in our opinion, can be considered as "a cold alternative" to a traditional "hot" melting-solidification preparation of alloys.