Spatially partitioned hybrid reinforcement architecture enables high-temperature strength and strain accommodation in a laser powder bed fused aluminum matrix composite
Description
This dataset contains 16 original image files supporting a study of the processing, microstructure, and elevated-temperature mechanical properties of an Al–Mn–Mg–Sc–Zr composite reinforced with 10 wt.% TiB₂ particles and fabricated by laser powder bed fusion (LPBF). The research investigates how processing conditions and particle–solute redistribution generate a spatially partitioned hybrid reinforcement architecture that combines mechanical strength with thermal stability. The composite was produced using 90 wt.% Al–5.15Mn–1.07Mg–0.72Sc–0.36Zr alloy powder and 10 wt.% micro- and submicron-scale TiB₂ particles. Processing optimization achieved a relative density of 99.6% at a laser power of 400 W and a scanning speed of 1100 mm/s. The study examines the effects of energy input on consolidation, defect formation, and microstructural development. Microstructural characterization using scanning electron microscopy, electron backscatter diffraction, transmission electron microscopy, and X-ray diffraction revealed a bimodal grain structure comprising fine equiaxed regions near melt-pool boundaries and elongated columnar cellular regions within melt-pool interiors. The columnar regions contained a quasi-continuous Al₆Mn intermetallic network, boundary-associated TiB₂ particles, and intragranular L1₂-Al₃(Sc,Zr) nanoprecipitates. The fine equiaxed regions featured discontinuous reinforcement distributions and interconnected α-Al matrix pathways. This heterogeneous architecture is interpreted in terms of local solidification conditions, heterogeneous nucleation, solute partitioning, and particle interactions with the advancing solid–liquid interface. The reinforcement-rich regions provide obstacles to deformation and help stabilize the microstructure, while interconnected matrix pathways facilitate strain accommodation. The optimized composite achieved an ultimate tensile strength of approximately 460 MPa at room temperature. At 630 K, its yield strength, ultimate tensile strength, and elongation were 91 MPa, 123 MPa, and 8.6%, respectively. Microhardness remained essentially unchanged after thermal exposure at 300 °C for 100 h. Post-deformation characterization further informed the interpretation of strengthening, recovery, and fracture mechanisms. The image collection provides supporting visual evidence for the relationships between LPBF processing, microstructural heterogeneity, and elevated-temperature performance. It should be used alongside the associated manuscript for experimental procedures, specimen conditions, image interpretation, and detailed discussion.
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Institutions
- Nanjing University of Aeronautics and AstronauticsJiangsu, Nanjing