Formation mechanisms of TiB2 tracks on Ti6Al4V alloy during selective laser melting of ceramic-metal multi-material

Multi-material selective laser melting (SLM) is a new development direction in additive manufacturing technologies to realize the incorporation of different materials within a single component. In this work, processing parameters, cross-sectional features and surface morphologies of TiB2 tracks on SLM-processed Ti6Al4V alloy layer were investigated. A processing window was determined by examining the type of molten pools and continuity of scanned tracks. Formation mechanism of microstructures at the cross-sections of TiB2 tracks was also discovered. At a high scan speed above 700 mm/s, the tracks all exhibited an unstable surface consisting of excessive shrinkage, spatters and cracks. Consequently, based on the experimental analysis and numerical simulations, a range of laser energy density from 0.67 J/mm to 1.50 J/mm at laser powers of 400-450 W was found to be a feasible scope of processing parameters to fabricate stable tracks of TiB2 on Ti6Al4V alloy by SLM. (C) 2020 Elsevier B.V. All rights reserved.