STEM/EDX Images
We have published a new article entitled “Tailoring the mechanical and degradation performances of Mg-2.0Zn-0.5Ca-0.4Mn alloy through microstructure design” in the JOM journal A novel Mg-2.0Zn-0.5Ca-0.4Mn alloy was formulated and processed through melt spinning and hot extrusion to enhance the mechanical and degradation properties. Microstructural characterization on the rapidly solidified alloy ribbons consolidated by extrusion (RS+Ex) revealed a fine and fully recrystallized microstructure with an average size of 4µm. The conventionally extruded (Ex) alloy consisted of several course second phase strips as coarse as 100 µm, while the RS+Ex was devoid of any second phases larger than 100 nm. RS+Ex processing resulted in significantly randomized texture where the majority of the basal planes were tilted toward transverse and extrusion directions. Such a weak texture resulted in higher activity of basal planes and thereby, considerably improved the fracture elongation from 4% to 19 %, while keeping relatively high tensile strength of 294 MPa. In addition to high strength and ductility due to the reduced activity of deformation twining during the compression, the RS+Ex alloy showed lower yielding asymmetric ratio than that measured for Ex alloy (1.25 vs 1.61). Electrochemical measurements and immersion tests indicate that applying RS+Ex remarkably reduces the corrosion rate from 2.49 to 0.37 mm/year due to recrystallization completion and suppression of coarse second phase formation.
