Investigation into the effect of solid solution chemistry on lattice parameters and microstructural properties of βeta -Ti alloys.

Abstract

This research aimed at investigating the changes in lattice parameters with increase in solute concentration. A vacuum arc furnace with a tungsten electrode was used for alloying purposes. The alloys were then annealed at 1000oC for 28 hours followed by quenching in ice-water. Five Ti-Mn and five Ti-Fe alloys were prepared within their solid solution range. In addition, commercially pure titanium was doped with up to 2.7%O with the aim of evaluating the effect of this on lattice parameters. Optical microscopy was used to study microstructures and XRD was utilized for lattice parameter determination. Lattice constants decrease with increase in solute concentration confirming the expected result since the solute elements are smaller than titanium. Grain size also decreased with increase in solute content. Hardness tests made confirmed an increase in hardness with solute concentration. This is caused by lattice straining as beta stabilizer concentration is increased.