Magnesium MetPregT as a Beryllium (Be) Material Replacement

Beryllium commands a unique position as a metal for engineering applications. It exhibits high thermal conductivity, modest thermal expansion, combines a high elastic modulus with a low density to exhibit an unsurpassed specific stiffness (modulus/density). However, the attributes of Be and its alloys are countered by two significant drawbacks: 1) toxicity, and 2) high cost. Over the past two decades MMCs have been the subject of significant academic studies and numerous commercialization attempts. For example, aluminum-matrix MMCs have exhibited desirable attributes such as significant increases in elastic modulus, tensile strength at room and elevated temperatures, fatigue strength, wear resistance, etc. Recently, the Missile Defense Agency has supported materials development approaches that would lead to structural materials systems to replace Be and Be alloys. Continuous graphite fiber reinforced magnesium is a viable candidate for Be replacement. The overall objective for this Phase I effort is to evaluate the feasibility of producing magnesium-matrix, continuous carbon fiber composites using Touchstone's MetPregT processing facility. The proposed feasibility evaluation entails modifying the MetPreg processing apparatus for handling magnesium safely, producing tape using two matrix alloys and two carbon fibers, measuring the tensile properties of fabricated tape, and performing microstructural characterizations.