Search Results

Two different shear sample geometries were employed to investigate the elastoplastic and failure behaviour of three automotive alloy rolled sheets; a highly anisotropic magnesium alloy (ZEK100) and two relatively isotropic dual phase steels (DP600 and DP780). The performance of the so-called butterfly type specimen (Mohr and Henn 2007, Dunand and Mohr 2011) was evaluated at quasi-static conditions along with the shear geometry of Peirs et al. (2012) using in situ 3-D digital image correlation (DIC) strain measurement techniques. It was shown that both test geometries resulted in similar trends of the load-displacement response; however, the fracture strains obtained using the butterfly specimen were lower for the ZEK100 and DP780. It was demonstrated that the ZEK100 exhibits strong anisotropy in terms of the shear work hardening rate and failure strain.

The purpose of this study was to conduct a comparative corrosion assessment of alloys and coating schemes of interest for the fabrication of multi-material lightweight vehicle architectures. Alloys considered for this application included galvanized high strength low alloy steel, aluminum alloy AA6111 and magnesium alloy ZEK100. The coating scheme considered for corrosion protection included a layered paint top-coat scheme that was applied to a pre-treated surface. The pre-treatments included an alloy-specific commercial conversion coating (CC) and a plasma electrolytic deposition (PED) process that was applied only to the ZEK100 material. The corrosion assessment of the scribed coated alloy panels was conducted after 1000 h exposure in the ASTM B117 salt fog environment. Characterization of the mode and extent of corrosion damage observed and the role played by the exposed alloy microstructure utilized both light optical microscopy and electron microscopy.