Microstructure and mechanical properties of Al-Cu alloy during wire and arc additive manufacturing by adding micron TiB2 particles

Abstract

ABSTRACT Micron TiB2 particles were added to the 2319 aluminum alloy using a surface coating method during the additive process. The study focused on the formation, microstructure, and properties in order to achieve deposited components with a uniform microstructure and enhancing strength and plasticity. The critical migration velocity (Vcr = 335 μm/s) of with micron-sized TiB2 particles addition was larger than the solidification rate, which caused particles to be pushed by the solid-liquid interface and ultimately reside at the grain boundary position. The micron-sized TiB2 particles reduced the activation energy for nucleation of the precipitation of the θ’ phase, lowered the energy barrier for nucleation, and introduced dislocations to create lattice distortion channels. This enabled rapid diffusion of solute atoms and facilitated the precipitation and growth of the θ’ phase. Finally, the transverse strength and elongation were higher, reaching 339.07 MPa and 21.3%, which increased by 45% and 60% respectively.