Experimental and numerical investigations into the deformation and fracture behavior of intermetallics and base materials in as-cast Al-Cu compounds

Abstract

This paper focuses on the mechanical characteristics of as-cast compounds consisting of brass/aluminum. It represents a novel simulation-aided experimental approach for the evaluation of the mechanical behavior of hybrid metallic and non-metallic structures. The bilayer components were fabricated through static compound casting and semi-continuous compound casting. The interface of the as-cast products exhibited intermetallic layers, as well as an anomalous eutectic area in between the base materials. Experimental push-out testing was performed in order to analyze the bonding strength and fracturing of monolithic and hybrid structures. The monolithic sample failure was simulated using the Johnson-Cook failure model. The respective Johnson-Cook parameters C1, C2, and C3 were determined as 0.001, 3.000, and 2.000 for CuZn37, 0.100, 2.000, and 9.000 for AA5083, 0.100, 1.000, and 2.000 for AA6060, as well as 0.100, 0.100, and 10.000 for AA7075. A hybrid push-out simulation model was calibrated in order to evaluate the mechanical behavior of hybrid specimens. Two different fracture models, the Johnson-Cook damage criterion and the brittle cracking model, were chosen for the intermetallic layers and anomalous eutectic region. The Johnson-Cook parameters were 0.05, 0.05, and 0.05 for the intermetallic layers, as well as 0.20, 0.20, and 0.20 for the anomalous eutectic area. The tensile strength of the brittle cracking model was 190 N mm-2 for both components. The calibrated and validated material properties were adapted to the simulation-aided investigation into the mechanical behavior during Brazilian testing. Testing of bilayer samples with disparate interfacial bonding underlined the importance of metallurgical bonding in as-cast brass/aluminum compounds.