Engineering of strong and hard in-situ Al-Al3Ti nanocomposite via high-energy ball milling and spark plasma sintering

Light-weight Al-Ti nanocomposites attract increasing attention due to the advancements in spacecraft and additive manufacturing. In this work, ab initio modeling, DSC, in-situ XRD experiments were used formulate a strategy for rapid fabrication of Al-Al3Ti with enhanced mechanical properties (ultimate tensile strength up 437 MPa at room temperature 109 500 °С, ~6% elongation before failure), resulting from mixed ductile-fragile deformation behavior. The investigated samples produced by spark plasma sintering high-energy ball-milled reactive composites Al-TiH2 leading precipitation 0.05–0.25 µm Al3Ti particles nanostructured Al matrix. Samples coarser TiH2 powder or higher content featured minor amount transitional core-shell structures incomplete conversion as-formed Ti into Al3Ti. following phase structure formation mechanism upon heating nanocomposite powders was proposed: Al+δ­TiH2→~450−500°СAl[Ti]+β­Ti[Al]+δ­TiH2−x→~550−600°СAl+Al3Ti. Tentative guidelines proposed based on analysis diffusion kinetics.