DBPapers
DOI: 10.5593/sgem2017H/63/S24.010

SYNTHESIS OF NANOCOMPOSITES FROM TI-AL-B-C POWDERS BY EXPLOSIVE CONSOLIDATION

M. Chikhradze, G. Oniashvili, Fernand D.S. Marquis
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-29-4 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 63, 77-84 pp; DOI: 10.5593/sgem2017H/63/S24.010

ABSTRACT

The development of materials science is in direct connection to the production of composite material with specific properties and to the technologies for their fabrication. The unique properties of the composites fabricated in Ti-Al-B-C systems makes them attractive for aerospace, power engineering, machine and chemical and other practical applications. Besides, Aluminum matrix composites (AMCs) have great potential as structural materials again due to their excellent physical, mechanical and tribological properties. The methodology and technology for the fabrication of bulk materials from ultrafine grained powders of Ti-Al-B-C system are described in this abstract.
According to the phase diagrams in binary and ternary system the composites/intermetallics may be obtained with wide spectrum of phase composition, in crystalline and amorphous (brittle and ductile) structures. Depending on the composition and structure, the synthesized composites may have different specific properties. The potential of the system for development of new structural/composite materials in different thermodynamic conditions is very attractive.
Nano structured composite materials of Ti-Al-B-C system, prepared in the form of micromechanical blends, solid solutions and intermetallic compounds are of great practical interest because of improved mechanical properties in comparison with coarse grain material (>1 μm).
The crystalline coarse Ti, Al, C powders and amorphous B were used as precursors, and blends with different compositions of Ti-Al-B-C and Ti-Al-C were prepared. The powders were mixed according the selected ratios of components to produce the blend.
For Mechanical alloying (MA) the high energetic “Fritsch” Planetary premium line ball mill was used. The mill was equipped with Zirconium Oxide jars and balls. Ratio ball to powder by mass was 5:1. The time of the processing was varied from 1 to 5 hours. Rotation speed of the jars was 500 rpm.
Consolidation of the samples was performed in two stages. The powder blend was loaded in the carbon steel tube container and at the first stage the pre-densification of the mixtures was performed under static press loading (intensity of loading P=500-1000 kg/cm2).
A card box was filled with the powdered explosive and placed around the cylindrical powder container. The experiments were performed at room temperature. The shock wave pressure was varied in the range of 5-20 GPa.
The motivation was derived from preliminary works showing that the explosive consolidation (EC) of metal-ceramic compositions is not only feasible but can produce materials of almost theoretical densities. The EC is the ecologically friendly technology, which allows obtaining bulk nanomaterials in a short period of time by using simple equipment and installations.
The bulk compacts were recovered in different shapes and prepared for investigations. The density of specimens was determined. The microstructure was studied by SEM. The effective technology/regimes for obtaining nanopowders and nanocomposites in Ti-Al-B-C composition has been elaborated.

Keywords: Nano structure, Composite materials, Explosive compaction, Nano technologies