Abstract
Delamination is a major limitation of lamellar composite structures in general, wherein interface/interphase control is a major factor. Studying/investigating the mitigation of cracks as well as toughening mechanisms is paramount to establish the control of interface/interphase kinetics. Stainless steel 316, Al 6082, CU–Zn sandwich laminate composite-sheets, in a foil–foil processing technique, were fabricated by means of hot uniaxial pressing. A parametric study was introduced using temperature and pressure effects on the composite specimens. The composite-sheet interface and its bond strength were investigated using scanning electron microscopy and tensile test. Microstructural as well as mechanical characterization, were established via optical and scanning electron microscopy; energy dispersive X-ray spectroscopy and mechanical testing. Mechanical characterization of the interfacial shear strength is investigated using hardness testing. The interphase kinetic behavior is observed through localized micro plasticity, metal flow and delocalized Al oxide and Mg oxide. Results showed that low temperature heat treatment can improve the morphology of stainless steel 316, Al 6082, CU–Zn interface and increase its bond strength. Alloying element segregation with diffusion mechanisms induced the formation of localized metal flow along with the interface. Alloy segregation during solidification in a semisolid state processing induces directional solidification with fibrous entities and oxides on structural interphase. For the stainless steel 316, Al 6082, Cu–Zn composite, the reasonable heat treatment is approximately 823 K for 1 and 3 h.