Recent Advances on the Solidification Processing of Cast Energetic Materials

This paper investigates the solidification of highly viscous energetic materials cast into a projectile. Active cooling and heating (ACH) control solidification technology as well as mechanical vibration (MV) are applied to achieve unidirectional solidification and to reduce cracks, gas pores, and shrinkage defects and to decrease the detrimental gap size between the projectile and the solidified energetic material. A comprehensive numerical model was developed to simulate the solidification processes during casting of energetic materials, as well as the resulting induced thermal stresses. The optimized design parameters of the proposed technologies are developed based on numerical modeling and experiment work. A detailed comparison between the latest experiments performed at the University of Alabama, Solidification Laboratory, obtained with electrical heating and water cooling and with and without mechanical vibration is provided in this paper. In these experiments, a special wax material (e.g., Chlorez 700S) that has similar thermo-physical properties with the IMX-104 explosive material was used. Experiments performed at the USARMY ARDEC using the IMX-104 explosive material with steam heating and water cooling are also presented in this paper. These experiments are being used to further validate the numerical model.