Strengthening mechanisms of Ti via Al addition

Abstract

Pure Ti is characterised by an interesting combination of performance from an engineering point of view. The addition of Al to Ti can be used to reduce the intrinsic cost of the material, decrease the density of the alloy, and increase the mechanical performance. This study is focused on evaluating the physical properties, microstructural evolution and mechanical behaviour of Ti-xAl alloys (where x = 1–6 wt%) in order to scientifically understand the strengthening mechanisms of the addition of Al to pure Ti manufactured via the conventional powder metallurgy route of cold uniaxial pressing plus solid state sintering. The addition of Al to Ti does not affect the compressibility of the alloy but changes the consolidation and densification of the alloy. The incremental addition of Al results in the progressive strengthening of Ti via the simultaneous contribution from substitutional solid solution and grain refinement strengthening which outdo the negative effect of the residual porosity.