Answer: thermite

AnswerCrossword Clue
THERMITEAluminum mixture used in welding.
THERMITEBomb ingredient.
thermitemixture of finely-divided metallic aluminum and ferric oxide that when ignited produces extremely high temperatures as the result of the union of the aluminum with the oxygen of the oxide: used in welding, incendiary bombs, etc.
thermitea metallic mixture that produces intense heat when ignited, also THERMIT