Strengthening of ultrafine PM aluminium using nano-sized oxycarbonitride dispersoids

► Al compacts processed with powders milled under different amounts of NH3 were prepared. ► NH3 is decomposed during milling and N is incorporated into the Al powder. ► Nano-sized N rich dispersoids, formed during sintering, restrain Al grain growth. ► Compact properties follow a linear trend with respect to the amount of N incorporated. ► Controlling NH3 allows producing ultrafine Al parts with pre-established properties.