• Cordill, M.J.; Jörg, T.; Többens, D.M.; Mitterer, C.: Improved fracture resistance of Cu/Mo bilayers with thickness tailoring. Scripta Materialia 202 (2021), p. 113994/1-5

10.1016/j.scriptamat.2021.113994
Open Access Version

Abstract:
The fracture toughness of Mo in Cu/Mo bilayers on polyimide was assessed with in situ X-ray diffraction during uniaxial tensile straining. The fracture resistance of Mo acting as an adhesion layer greatly depends on the thickness of the Cu layer exhibiting a toughening effect with increasing Cu layer thickness. In contrast, the presence of the Mo interlayer greatly decreases the apparent K_Ic of the Cu layers. The quantification of K_Ic for Mo with a Cu top layer provides further evidence that when brittle layers are used, a thicker ductile layer is advantageous to create fracture resistant stretchable systems.