A capsule can include a shell that defines at least a portion of a chamber; and a mixture of an explosive and a thermally conductive material disposed in the chamber. A method can include forming a mixture of an explosive and a thermally conductive material; disposing at least a portion of the mixture in a chamber of a capsule; and at least partially sealing the chamber.

The present application discloses a variety of improvements that enhance at least one of the mechanical, chemical/energetic, ballistic, or adhesive properties, of a class of ECPs, regardless of whether said ECPs are in solid phase or gels, singly or in combinations thereof.

A liquid electrically initiated and controlled composition comprising an oxidizer, soluble fuel additive(s), and other optional additives to enhance the chemical or ballistic properties, or a combination thereof is disclosed. The liquid composition further comprises stabilizers to enhance thermal stability, sequestrants to minimize deleterious effects of transition metal contaminants, and combustion enhancers maximizing efficiency. Buffers and heavy metal sequestering or complexing agents may be used in combination to achieve the highest degree of thermal stability. Additional ionic co-oxidizers may be added to the liquid composition to stabilize the liquid oxidizer and further depress freezing point. The liquid phase of matter allows flow via pipes or tubes from tanks, reservoirs, or other containers, through metering valves, followed by ignition or combustion modulation when stimulated by electrodes, statically or dynamically.

Disclosed herein are exothermic reaction mixtures that can be used for copper-based thermite reactions. The disclosed exothermic reaction mixtures can be advantageously formulated with synthetically made copper oxide(s), which can improve consistency and stability of thermite reactions. An example exothermic reaction mixture includes an alloy comprising copper and aluminum and a metal oxide comprising Cu.sub.2O and CuO. Also disclosed are methods of preparing the exothermic reaction mixture and methods of welding that include the exothermic reaction mixture.