Selective laser melting (SLM) has been widely used in production of titanium alloy parts in recent years

but its performance is limited by process defects and martensite microstructure. The research progress of defects and microstructure of as-built SLM–Ti–6Al–4V was summarized

including defects types and microstructure types

the effect of adjusting process parameters on reducing defect and regulating microstructure

and the β→α phase transformation research based on variant selection. Based on the main research mentioned above

improving the relationship between process parameters and microstructure characteristics and studing the influence of process parameters on phase transformation variant selection will be the focused directions in the further research.