Akademik Veri Yönetim Sistemi
Powder Technology, cilt.474, 2026 (SCI-Expanded, Scopus)
This study investigates the recycling of Co–Cr–Mo–W support structures generated during laser powder bed fusion (LPBF) via mechanical milling and their reuse as powder feedstock. Support structures were milled at rotational speeds of 300–500 rpm for durations up to 10 h, and the resulting powders were systematically characterized. Milling at 500 rpm for 6 h (S10) yielded the most favorable powder characteristics, including a relatively narrow particle size distribution (D50 ≈ 26 μm), reduced oxygen content, and stabilization of the γ-FCC phase. Prolonged milling promoted cold welding and agglomeration, leading to a deterioration in powder quality. The recycled S10 powder was subsequently reused in LPBF processing. Initial fabrication using standard parameters resulted in defects such as balling and delamination; however, optimization of processing conditions (100 W laser power, 600 mm/s scan speed, 40 μm hatch spacing, 20 μm layer thickness, and an alternating scan strategy) enabled the production of dense and defect-free specimens. The optimized Re–CoCr alloy exhibited a hardness of 416 HV0.5, a density of 7.477 g/cm3 (90–92% of theoretical), and an ultimate tensile strength of 450 MPa with limited elongation (1%). These results demonstrate the technical feasibility of recycling LPBF support structures into reusable Co–Cr–Mo–W powder feedstock, while highlighting that reduced ductility may constrain application to non-critical biomedical components. Cost analysis further revealed that recycling-assisted LPBF production reduced material costs by approximately 97% compared with commercial gas-atomized powders, underscoring the strong economic potential of the proposed recycling route.