Microstructure characterization, mechanical properties, compressibility and sintering behavior of Al-B4C nanocomposite powders

In the present work, Al-xB(4)C nanocomposite (x = 0, 1, 2, 3, 4 and 5 in wt%, having the average B4C size of 50 nm) were prepared using a high-energy ball mill. The milling times up to 16 h were applied. Then, the microstructural evolutions, mechanical properties, compressibility and sintering behavior of nanocomposites were investigated. The changes in powders morphology and microstructure during the milling process were characterized by laser diffraction particle size analyzer (LDA), SEM, XRD, EDS and TEM techniques. Compressibility and sintering behavior of milled powders compacted under different pressures (100-900 MPa) and at different sintering temperatures (500, 550 and 600 degrees C) were also studied. The pressing behavior of the nanocomposites was analyzed using linear compaction equations developed by Heckel, Panelli-Filho and Ge. The results showed the significant effects of B4C amounts and sintering temperatures on the compressibility and sintering behavior of nanocomposites. The increase in the B4C amount led to a decrease in both the compressibility rate and the sinterability of specimens. The maximum compression strength of 265 MPa and Vickers hardness of 165 VHN were obtained for Al-5 wt.% B4C nanocomposite milled for 16 h followed by sintering at 600 degrees C. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.