Enhanced Interfacial Joining Strength of Mg/Ti Bimetal Casting via 3D-Printed Ti-Based Lattice Material

This study innovatively joins magnesium and titanium alloys by incorporating a 3D-printed lattice structure into a magnesium alloy melt via compound casting. Simulation results highlight the significant effect of the length-to-diameter ratio (l/d_s) and node-to-strut diameter ratio (d_n/d_s) on joint strength, with the inclination angle (ω) deemed negligible. X-ray microcomputed tomography reveals a minimal 0.048% porosity in the bimetal joint with a cell dimension of 9 mm, prepared at a casting temperature of 730 °C. Experimental validation affirms the optimized lattice structure yielding impressive Mg/Ti composite joining strength (95.4 MPa) and fracture energy (8987 J). This optimal structure with l/d_s, d_n/d_s, and ω of 5.8, 2.4, and 56° respectively, leverages rough surface texture from selective laser melting, promoting a serrated interface for enhanced Mg/Ti bimetallic bonding.