Reactive fragment materials made from an aluminum–silicon eutectic powder

Abstract

We explore the use of an aluminum–silicon eutectic powder to produce reactive materials that fragment and combust following high-velocity impact. Unlike the pure aluminum powders traditionally used in these materials, the eutectic sinters readily and has a reduced melting point. This allows the tensile strength/ductility and fracture toughness to be tuned with partial sintering; increases in these properties, however, generally result in a reduction in combustion energy release on impact. Three heat treatments were studied for isostatically compressed aluminum–silicon materials, and two baseline pure aluminum materials using fine and coarse powders were also fabricated for comparison. Mechanical measurements and impact calorimetry tests showed that partial sintering at the nominal melting point increases tensile strength and toughness by approximately 350% but does reduce combustion energy output; however, the reduction is only prominent above 1300 m/s for the conditions studied here. Below this point, the partially sintered Al–Si has similar impact-induced combustion as an extremely brittle, unannealed pressed Al powder. Pure aluminum and alloy materials with similar mechanical properties and starting particle size show comparable combustion energy release, suggesting that powder size and fragmentation properties are more important than the variation in melt point.

Document Details

Document Type
Pub Defense Publication
Publication Date
Aug 13, 2020
Source ID
10.1063/5.0014011

Entities

People

  • Benjamin T. Miles
  • Jacob Kline
  • Joseph P Hooper
  • Stanley Wang

Organizations

  • Defense Threat Reduction Agency
  • Naval Postgraduate School
  • Office of Naval Research

Tags

Fields of Study

  • Materials science

Readers

  • Combustion science or combustion engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Powder metallurgy of Titanium alloys.