## 4 Conclusions  
A study of the effects of quasi-static strain rates and temperature on the microstructures of various forms of the Ti6 Al4V(ELI) alloy produced using LPBF was presented in this paper. The following conclusions were deduced from the obtained results:  
* The heat treatment of LPBF Ti6 Al4V(ELI) at temperatures near the \(\alpha\)\(\rightarrow\)\(\beta\) transformation temperature leads to the growth of \(\alpha\)-laths and therefore the coarsening of the microstructure. The heat treatment of this alloy above the \(\alpha\)\(\rightarrow\)\(\beta\) transformation temperature, followed by furnace cooling, results in the formation of typical Widmanstitten microstructures characterised by colonies consisting of several parallel \(\alpha\)-laths. * The \(\alpha\)-phase is dominant in the annealed microstructures of LPBF Ti6 Al4V(ELI). However, the volume fraction of the \(\beta\)-phase increases with increasing heat treatment temperature. * The flow stresses in different forms of LPBF Ti6 Al4V(ELI) generally increase with increasing strain rate and decrease with increasing test temperatures. However, the effects of strain rate are comparatively low. * The yield and flow stresses are dependent on the thickness of the \(\alpha\)-laths, and it is worth noting here that the microstructure of LPBF Ti6 Al4V(ELI) with fine \(\alpha\)-laths (sample C) recorded the highest values of these properties at all test conditions. While both the Hall-Petch effect and the presence of LAGBs contribute to the strengthening of materials, the effects of grain size (the Hall-Petch effect) outweigh those of LAGBs in the manner in which they increase the yield and flow stresses in the LPBF Ti6 Al4V (ELI) alloy. * The strain hardening rate is higher for finer microstructures of the LPBF Ti6 Al4V (ELI) alloy. Figure 19: Typical microstructure of samples E deformed at a temperature of 500 \({}^{\circ}\)C and strain rates of (**a**) 0.001 s\({}^{-1}\), (**b**) 0.005 s \({}^{-1}\), and (**c**) 0.1 s\({}^{-1}\). An increase in test temperature decreases the strain hardening rate in the LPBF Ti6 Al4V (ELI) alloy. * The deformation of LPBF Ti6 Al4V(ELI) is generally characterised by the formation of ASBs. Flow stress localization for this alloy at quasi-static strain rates occurs at higher plastic strains for tests conducted at high temperatures. Future research should attempt to investigate the in situ rise in temperature inside the material during high-strain-rate deformation. Conceptualization, A.M., M.M., and W.d.P. ; methodology, A.M.; validation, A.M.; formal analysis, A.M.; writing--original draft preparation, A.M.; writing--review and editing, A.M., M.M., and W.d.P. ; supervision, M.M. and W.d.P. ; funding acquisition, W.d.P. All authors have read and agreed to the published version of the manuscript. This research was funded by the South African Department of Science and Innovation (DSI) through the Council for Scientific and Industrial Research (CSIR) for the Collaborative Program in Additive Manufacturing, Contract No. : CSIR-NLC-CPAM-21-MOA-CUT-01. Not applicable. The datasets presented in this study are available on request from the corresponding author; they are not publicly available as they form part of an ongoing research. The authors acknowledge and thank the Centre for Rapid Prototyping and Manufacturing (CRPM) of the Central University of Technology, Free State (CUT), for the production of test samples used in this study. The Centre for Materials Engineering of the University of Cape Town is also acknowledged for providing the Geeble machine used in this study. The Material Testing Lab of the Council for Scientific and Industrial Research (CSIR) is also acknowledged for providing the universal testing machine used in this study. The authors declare no conflicts of interest.