The second part of this presentation will focus on microscale testing under extreme conditions of pressure, temperature and strain rate. In particular we will look at the response of body centered cubic (bcc) Mg, stabilized at ambient pressures in a Mg/Nb multilayer nanocomposite. We investigated the structure of the hitherto-unknown bcc Mg phase in the nanocomposite under high pressures in a diamond anvil cell experiment using synchrotron radiation x-ray diffraction. Additionally, Pathak's team performed high temperature micro-pillar compression tests and strain rate jump tests on Mg (bcc)/Nb 5nm/5nm and Mg (hcp)/Nb 50nm/50nm nanolaminates to compare the responses of hcp vs. bcc Mg. Results from these tests were analyzed in terms of the measured activation energies and activation volumes from sub-micrometer sized Mg/Nb multilayer nanocomposites.