Porous Si-Sn alloys produced by mechanical alloying and subsequent consolidation by sintering and hot-pressing

ABSTRACT

Porous Si_100-xSn_x samples with x = 15, 30 and 40 at.% were produced from Si and Sn elemental powders by mechanical alloying followed by two different compaction and sintering processes: cold uniaxial pressure and subsequent sintering at 220°C, and hot pressing at 240°C. The results showed that it is possible to produce samples with a major porosity of close to 0.1 μm. The porosity of the Si₇₀Sn₃₀ sample that was mechanically alloyed for 12 h and synthesized by the former process is in the mesoporous region. The structure of all the final samples is composed of the Si, Sn and SnO phases.

KEYWORDS:

• Silicon
• tin
• mechanical
• alloying
• sintering
• hot
• pressing
• particle
• size
• morphology
• structure
• porosity

Acknowledgments

This research was supported by FEDER Funds through Portugal 2020 (PT2020), through project Centro 2020 000014 MATIS 2020, by the Competitiveness and Internationalization Operational Program (COMPETE 2020) and national funds through the Portuguese Foundation for Science and Technology (FCT), under the project UID/EMS/00285/2020.