MECHANICAL-PROPERTIES OF AN IN-SITU SYNTHESIZED NB NB3AL LAYERED COMPOSITE/

A layered metal/intermetallic, consisting of Nb and Nb3Al, has been sy nthesized using a high rate magnetron sputtering technique. The micros tructure and various mechanical properties have been explored. It is d emonstrated that the Nb phase contributes substantially to the toughne ss, through plastic dissipation, combined with frictional sliding at c ontacting surfaces. However, the toughness is suboptimal, because of t he small layer thickness, which limits the width of the plastic zone. The tensile strength is also relatively low, because of growth defects . Some concepts for improving the strength and fracture resistance by tailoring the constituent and interface properties are suggested.