Fatigue life and cyclic creep of tantalum/copper/steel layerwise plates under tension loading at room temperature

The unique properties of tantalum make it extremely desirable in demanding branches of industry. Its limited availability necessitates its efficient use. High efficiency can be achieved by producing layerwise-heterostructured plates with a tantalum layer. However, the exposure of this composite to fatigue loading is being questioned because it has never been tested under such conditions. The purpose of this study was to investigate the fatigue behavior of an explosively manufactured composite with an outer tantalum layer under cyclic loading. The microcracks that developed along the slip lines in the grains of the tantalum layer were found and identified as the initial damage mechanisms that led to cyclic creep. The composite plates exhibited superior fatigue strength compared with the homogenous tantalum plate.