Effects of Al and W Particle Size on Combustion Charac- teristics and Dynamic Response of W-PTFE-Al Composites

The variation of metallic particle size alters the combustion characteristics and dynamic response of W-PTFE-Al composites. Combustion test results show that with Al particle size decreasing from 10 μm to 1 μm, W particle size increasing from 0.1 μm to 7 μm, the reaction energy of W(7 μm)-PTFE(40 μm)-Al(1 μm) reaches 4570.2 J/g in argon environment and 9848.1J/g in oxygen environment, indicating fine aluminum and coarse tungsten contribute to the increase of reaction energy. Under dynamic loading, the deflagration time of all four kinds of W-PTFE-Al composites is longer than 500 μs. With the decrease of Al particle size, the insensitivity of W-PTFE-Al composites to impact shows a decreasing tendency since the absorbed critical energy before reaction decreases by 14.0%. With the decrease of W particles size, the insensitivity of W-PTFE-Al composites to impact enhances due to the absorbed critical energy before reaction increases by 34.8%. The dynamic compression results show that the ultimate strength of W-PTFE-Al composites increases by 8.0% with Al particle size changing from 10 μm to 1 μm, but decreases by 10.2% with W particle size changing from 7 μm to 100 nm.