Formation of HfW_2 and ZrW_2 in the W-Hf and W-Zr Binary Systems

摘要

The lethality of depleted uranium (DU) as a kinetic energy penetrator (KEP) is primarily ascribed to its high density 18.95 g/cm~3 and its ability to undergo adiabatic shearing. Due to environmental hazards and associated costs alternative materials have been under investigation for DU replacement. An intriguing replacement, toughened tungsten (W) based bulk metallic glass would inherently incorporate the necessary physical attributes for an ideal KEP. There are binary systems from which the basis for glass formulation is possible. While the phase diagrams for the binary systems W-Hafnium (Hf) and W-Zirconium (Zr) are similar, equilibrium melting studies preclude the use of Hf for the basis of formulating a glass due to the formation of the HfW2 intermetallic. Hafnium is advantageous as it has a relative density of 2 compared to Zr and thus will result in a higher density glass. The current investigation is to utilize a non equilibrium method, such as high energy mechanical alloying, to investigate if the suppression of HfW2 can be accomplished.