ALTERNATIVE OXIDANTS FOR SILICON FUEL IN TIME-DELAY COMPOSITIONS

Abstract

Antimony trioxide, lead chromate, and copper antimonite are suitable oxidants for silicon metal in time-delay compositions ignitable by shock tubing. Measured burn rates for these systems vary from 6 to 30 mm/s. Lead chromate mixtures burned fastest under comparable conditions. The latter two systems show a bimodal burn rate versus silicon content dependence with a local minimum in burn rate at about 35 mass% silicon. Addition of aluminium powder or fumed silica reduces burn rate. Copper antimonite–zinc antimonite coprecipitates provide for faster burning than neat copper antimonite–silicon mixtures.

Keywords:

• pyrotechnic
• composition
• burn rate
• antimonite
• silicon

Financial support from the THRIP programme of the Department of Trade and Industry and the National Research Foundation as well as African Explosives Limited is gratefully acknowledged. We also thank Dr S. van der Walt for helping with the setup of the equipment and programming used for the burn speed measurements.

Notes

σ* = multiplicative standard deviation (log-normal distribution).