Comparative investigations of the mechanically alloyed and pressureless sintered Al–7 wt.% si composites reinforced with various boride particles

  • 1 Istanbul Technical University, Faculty of Chemical and Metallurgical Engineering, Department of Metallurgical and Materials Engineering,


This study reports the milling time optimization of the Al-7 wt.% Si alloys by using planetary ball mill, the incorporation of 2 wt.% LaB6, NbB2, VB and TiB2 particles into Al-7 wt.% Si matrix and the fabrication of composites using cold pressing and pressureless sintering. Mechanical alloying (MA) time carried out for 4, 8, 12, 16 and 20 h was optimized via crystallite size and phase determinations and microstructural investigations. 12 h was chosen as optimum MA time. Then, different particulate reinforcements were added to Al-7 wt.% Si matrix to constitute boride reinforced composites. All composite powder batches were also milled for 12 h, then compacted and
sintered at 570°C for 5 h. Microstructural, physical and mechanical (hardness and wear volume loss) properties of these composites were performed. Hardness values of 120.8 ± 11.37 and 121.77 ± 19.02 were obtained for the LaB6 and TiB2 reinforced composites, respectively.



  1. D. Garbiec, M. Jurczyk, N. Levintant-Zayonts, T. Mościcki, Properties of Al-Al2O3 composites synthesized by spark plasma sintering method, Archives of Civil and Mechanical Engineering. 15 (2015) 933–939. doi:10.1016/j.acme.2015.02.004.
  2. M. Hossein-Zadeh, M. Razavi, M. Safa, A. Abdollahi, O. Mirzaee, Synthesis and structural evolution of vanadium carbide in nano scale during mechanical alloying, Journal of King Saud University - Engineering Sciences. 28 (2016) 207–212. doi:10.1016/j.jksues.2014.03.010.
  3. S.Q. Wu, H.Z. Wang, S.C. Tjong, Mechanical and wear behavior of an Al/Si alloy metal-matrix composite reinforced with aluminosilicate fiber, Composites Science and Technology. 56 (1996) 1261–1270. doi:10.1016/S0266-3538(96)00085-1.
  4. A.K. Bodukuri, K. Eswaraiah, K. Rajendar, V. Sampath, Fabrication of Al–SiC–B4C metal matrix composite by powder metallurgy technique and evaluating mechanical properties, Perspectives in Science. 8 (2016) 428–431. doi:10.1016/j.pisc.2016.04.096.
  5. K.D. Woo, D.L. Zhang, Fabrication of Al-7wt%Si0.4wt%Mg/SiC nanocomposite powders and bulk nanocomposites by high energy ball milling and powder metallurgy, Current Applied Physics. 4 (2004) 175–178. doi:10.1016/j.cap.2003.11.002.
  6. W.K. Kang, F. Yilmaz, H.S. Kim, J.M. Koo, S.J. Hong, Fabrication of Al-20 wt%Si powder using scrap Si by ultra high-energy milling process, Journal of Alloys and Compounds. 536 (2012) S45–S49. doi:10.1016/j.jallcom.2012.01.106.
  7. W.S. Miller, L. Zhuang, J. Bottema, A.J. Wittebrood, P. De Smet, A. Haszler, A. Vieregge, Recent development in aluminium alloys for the automotive industry, Materials Science and Engineering: A. 280 (2000) 37–49. doi:10.1016/S0921-5093(99)00653-X.
  8. E. Tekoğlu, D. Ağaoğulları, S. Mertdinç, A.H. Paksoy, M.L. Öveçoğlu, Microstructural characterizations and mechanical properties of NbB2and VB particulatereinforced eutectic Al-12.6 wt% Si composites via powder metallurgy method, Advanced Powder Technology. (2018). doi:10.1016/j.apt.2018.05.013.
  9. R. Flores-Campos, D.C. Mendoza-Ruiz, P. AmézagaMadrid, I. Estrada-Guel, M. Miki-Yoshida, J.M. HerreraRamírez, R. Martínez-Sánchez, Microstructural and mechanical characterization in 7075 aluminum alloy reinforced by silver nanoparticles dispersion, Journal of Alloys and Compounds. 495 (2010) 394–398. doi:10.1016/j.jallcom.2009.10.209.
  10. M.S. El-Eskandarany, Introduction, Mechanical Alloying. (2015) 1–12. doi:10.1016/B978-1-4557-7752-5.00001-2.
  11. C. Suryanarayana, Mechanical alloying and milling, Progress in Materials Science. 46 (2001) 1–184. doi:10.1016/S0079-6425(99)00010-9.
  12. Ö. Balci, D. Aǧaoǧullari, H. Gökçe, I. Duman, M.L. Öveçoǧlu, Influence of TiB2 particle size on the microstructure and properties of Al matrix composites prepared via mechanical alloying and pressureless sintering, Journal of Alloys and Compounds. 586 (2014) s78–s84. doi:10.1016/j.jallcom.2013.03.007.
  13. J. Milligan, R. Vintila, M. Brochu, Nanocrystalline eutectic Al-Si alloy produced by cryomilling, Materials Science and Engineering A. 508 (2009) 43–49. doi:10.1016/j.msea.2008.12.017.

Article full text

Download PDF