Akademik Veri Yönetim Sistemi
Additive Manufacturing Congress 2026, Antalya, Türkiye, 13 - 15 Nisan 2026, ss.63, (Özet Bildiri)
Laser Powder Bed Fusion (LPBF) of Ti6Al4V is inherently limited by steep thermal gradients, leading to martensitic microstructures, residual stresses, and anisotropic mechanical behaviour. To address these limitations, this study investigates the integration of Diode Point Melting (DPM) with Dynamic Laser Assisted Heating (DLAH) in laser powder bed fusion, with a focus on thermal management, microstructural evolution, and mechanical response.
A multi-laser system employing low-power 450 nm diode emitters was utilised, where DPM enabled localised melting while DLAH provided controlled in-situ pre- and post-heating during layer deposition. Multi-layer Ti6Al4V specimens were fabricated under varying laser heating temperatures, and their relative density, surface roughness, phase constitution, grain morphology, and mechanical properties were systematically characterised using density measurements, SEM-EDS, XRD, EBSD, nano-indentation, and profilometry-based tensile testing.
The results demonstrate that the introduction of DLAH significantly enhances process stability in multi-layer builds, achieving relative densities exceeding 99.5% while reducing surface roughness compared to non-heated DPM conditions. Microstructural analysis reveals a clear transition from fine acicular α′ martensite towards coarser α + β morphologies with increasing laser heating temperature, accompanied by parent β grain refinement and reduced crystallographic texture intensity. Mechanical characterisation shows a balanced improvement in ductility and elastic modulus with only a marginal reduction in ultimate tensile strength, indicating effective mitigation of excessive martensitic hardening.
These findings confirm that DPM–DLAH integration provides a scalable and energy-efficient route for microstructural tailoring in multi-layer additive manufacturing of Ti-6Al-4V, bridging the performance gap between conventional LPBF and preheated electron beam processes while maintaining high spatial and thermal control.