Shock compression response of magnetic nanocomposite powders

• Published in: Acta materialia Vol. 52; no. 8; pp. 2147 - 2154
• Main Authors: Jin, Z.Q., Chen, K.H., Li, J., Zeng, H., Cheng, S.-F., Liu, J.P., Wang, Z.L., Thadhani, N.N.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 03.05.2004; Elsevier Science
• Subjects: Chemical synthesis; combustion synthesis; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fine-particle systems; Hard magnets; Impact behavior; Magnetic properties and materials; Materials science; Materials synthesis; materials processing; Nanocomposite; Nanostructure; Physics; Powder consolidation; Small particles and nanoscale materials; Studies of specific magnetic materials; Nanocomposite; Nanostructure; Hard magnets; Impact behavior; Powder consolidation; Magnetic powder; Ternary alloys; XRD; Magnets; Dispersion strengthened metal; Consolidation; Praseodymium alloys; Impact strength; Shear band; Electric fields; Iron base alloys; Magnetic properties; Scanning electron microscopy; Densification; Experimental study; Powder metallurgy; Boron alloys; Shock waves; Transmission electron microscopy; Nanocomposites; Microstructure
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2004.01.006

The shock compression response of magnetic Pr 2Fe 14B/α-Fe nanocomposite powders, pressed at different packing densities, was studied in the range of 11–23 GPa shock pressure, using a single-stage gas gun. Bulk compacts (97.5–99% dense) recovered in the form of 12 mm diameter by 4 mm thick disks, were analyzed to determine the structural changes occurring within the particles and at particle boundaries. Scanning electron microscopy observations revealed presence of laminar morphology and strong inter-particle bonding. X-ray diffraction and transmission electron microscopy analysis revealed the retention of nanoscale structure and localized grain refinement. Shear bands were observed and thought to be responsible for the grain refinement. The compact of powders pressed at the intermediate packing density (∼76% dense) showed the best densification characteristics, correspondingly, the best magnetic properties with strongest exchange coupling between hard and soft phases.