Qualitative and quantitative assessment of microstructure in Al-B4C metal matrix composite processed by modified stir casting technique

Abstract Recently, boron carbide reinforced aluminum matrix composites have witnessed an unprecedented technological significance as a structural neutron-shielding material for nuclear waste and nuclear submarines. The present study deals with processing of 6061Al-B 4 C composites containing different wt.% of B 4 C using modified stir casting method with bottom pouring arrangement. The dispersion of B 4 C particles in the aluminum matrix, interfacial characteristics and microstructural features were qualitatively characterized using field emission scanning electron microscope (FESEM) and optical microscope. Microstructural characterization revealed that the dispersion of B 4 C particles in the matrix was relatively uniform and at some locations small scale agglomeration and clustering of particles were observed. Particle size distribution has been studied for the quantitative description of agglomeration of B 4 C particles in the matrix which reveals the presence of small scale agglomeration of particles. Homogeneity and randomness of B 4 C particles in the matrix has been calculated by quadrat method. The results show a random spatial distribution of particles with small scale clustering. Microindentation test were performed on the fabricated composite and obtained results were statistically evaluated.

[1]  A. D. Damodaran,et al.  Fracture behaviour of pressure die-cast aluminium-graphite composites , 1995, Journal of Materials Science.

[2]  N. Chawla,et al.  Modeling the effect of particle clustering on the mechanical behavior of SiC particle reinforced Al matrix composites , 2006 .

[3]  A. Kennedy.  The microstructure and mechanical properties of Al-Si-B4C metal matrix composites , 2002 .

[4]  K. Chawla,et al.  Metal Matrix Composites , 2006 .

[5]  M. Hashmi,et al.  Particle distribution in cast metal matrix composites—Part I , 2002 .

[6]  Maxence Bigerelle,et al.  Statistical analysis of the Vickers hardness , 1999 .

[7]  Jianghong Gong,et al.  Examination of the indentation size effect in low-load vickers hardness testing of ceramics , 1999 .

[8]  F. Toptan,et al.  Microstructural variations in cast B4C-reinforced aluminium matrix composites (AMCs) , 2008 .

[9]  R. M. Pillai,et al.  Reinforcement coatings and interfaces in aluminium metal matrix composites , 1998 .

[10]  D. Brabazon,et al.  Development and assessment of a new quick quench stir caster design for the production of metal matrix composites , 2005 .

[11]  M. Surappa,et al.  Directional dendritic solidification of a composite slurry: Part I. Dendrite morphology , 1998 .

[12]  U. Ramamurty,et al.  Subsurface deformation during Vickers indentation of bulk metallic glasses , 2004 .

[13]  Z. Zhang,et al.  Fluidity and microstructure of an Al–10% B4C composite , 2009, Journal of Materials Science.

[14]  Ahmet Karaaslan,et al.  Processing and microstructural characterisation of AA 1070 and AA 6063 matrix B4Cp reinforced composites , 2010 .

[15]  Ali Mazahery,et al.  Mechanical Properties of Squeeze-Cast A356 Composites Reinforced With B4C Particulates , 2012, Journal of Materials Engineering and Performance.

[16]  Helen V. Atkinson,et al.  A model-based analysis of particle size distributions in composite materials , 2003 .

[17]  D. Miracle.  Metal matrix composites – From science to technological significance , 2005 .

[18]  I. Roman,et al.  Vickers microindentation of WC–12%Co thermal spray coating: Part 1: statistical analysis of microhardness data , 2000 .

[19]  N. Chawla,et al.  On the correlation between hardness and tensile strength in particle reinforced metal matrix composites , 2001 .

[20]  J. Cornie,et al.  Wetting of ceramic particulates with liquid aluminum alloys: Part II. Study of wettability , 1989 .

[21]  R. Velmurugan,et al.  Production and mechanical properties of SiCp particle-reinforced 2618 aluminum alloy composites , 2008, Journal of Materials Science.

[22]  S Tzamtzis,et al.  Processing of advanced Al/SiC particulate metal matrix composites under intensive shearing – A novel Rheo-process , 2009 .

[23]  Sie Chin Tjong,et al.  Microstructural and mechanical characteristics of in situ metal matrix composites , 2000 .

[24]  A. Elaya Perumal,et al.  Influence of B4C on the tribological and mechanical properties of Al 7075–B4C composites , 2013 .

[25]  A. K. Suri,et al.  Synthesis and consolidation of boron carbide: a review , 2010 .

[26]  Brian Cantor,et al.  Characterization of Reinforcement Distribution in Cast Al-Alloy/SiCp Composites , 1998 .

[27]  B. Dhindaw,et al.  Processing of Ultrafine-Size Particulate Metal Matrix Composites by Advanced Shear Technology , 2009 .

[28]  C. C. Berndt,et al.  Statistical analysis of microhardness variations in thermal spray coatings , 1995 .

[29]  J. Bouix,et al.  Chemical reactivity of aluminium with boron carbide , 1997 .

[30]  Aykut Canakci,et al.  Pre-treatment process of B4C particles to improve incorporation into molten AA2014 alloy , 2007 .

[31]  P. S. Nair,et al.  Processing of surface-treated boron carbide-reinforced aluminum matrix composites by liquid–metal stir-casting technique , 2011 .

[32]  J. Gong,et al.  Effect of load-dependence of hardness on indentation toughness determination for soda-lime glass , 2001 .

[33]  M.S.J. Hashmi,et al.  Metal matrix composites: production by the stir casting method , 1999 .