Printing parameters for titanium powder in a Truprint 1000 to improve density and surface finish

<p dir="ltr"><b>Purpose</b>: Identify optimum laser settings and scanning strategies for titanium powder in a Trumpf Truprint 1000 to maximise density and minimise secondary roughness of printed parts.</p><p dir="ltr"><b>Methodology</b>: Volumetric energy density (VED) was controlled via laser power and speed in the manufacturing of solid coupons. Relative density and surface finish (i.e., secondary roughness and its thickness) were measured. Optimum parameters were validated using porous lattices.<br><b>Findings</b>: High density (99.6 ± 0.1%) and minimal secondary roughness (thickness 75 ± 2 μm, Sa 2.9 ± 0.2 μm, Sz 30.1 ± 2.8 μm) coupons were achieved using 108 W laser power, 889 mm/s laser speed, 55 μm hatch distance and 20 μm layer height to deliver VED 110 J/mm³ via a ‘double pass’ of VED 55 J/mm³ in a conformal infill fashion. The validation lattices displayed improved strut line profiles and fewer internal voids, and open porosity closer to the design intent.</p><p dir="ltr"><br><b>Originality</b>: The effectiveness of the ‘double pass’ conformal style to increase density without compromising secondary roughness resides in the doubling of the VED experienced at the core of the component whilst leaving its edges unaffected.</p><p dir="ltr"><br><b>Practical Implications</b>: The inherent variability present across machines and materials requires that the printing parameters have to be optimised for each pair. Initiatives to digitalise processes are needed to support our understanding of these variabilities. Our results contribute to the AM community efforts to compile experimental data that tabulates hardware performance in pursuit of that digitalisation</p>