Effects of copper content on the shell characteristics of hollow steel spheres manufactured using an advanced powder metallurgy technique

Abstract

Metallic hollow spheres are used as base materials in the manufacture of hollow sphere structures and metallic foams. In this study, steel hollow spheres were successfully manufactured using an advanced powder metallurgy technique. The spheres’ shells were characterized by optical microscopy in conjunction with microstructural image analysis software, scanning electron microscopy (SEM), energy- dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The microscopic evaluations revealed that the shells consist of sintered iron powder, sintered copper powder, sodium silicate, and porosity regions. In addition, the effects of copper content on various parameters such as shell defects, microcracks, thickness, and porosities were investigated. The results indicated that increasing the copper content results in decreases in the surface fraction of shell porosities and the number of microcracks and an increase in shell thickness.

Keywords

steel hollow spheres / powder metallurgy / copper content / shell characteristics

References

[1] Gibson L.J., Ashby M.F. Cellular Solids: Structure and Properties, 1997, Cambridge, Cambridge University Press

[2] Ashby M.F., Evans T., Fleck N.A., Gibson L.J., Hutchinson J.W., Wadley H.N.G. Metal Foams: a Design Guide, 2000

[3] Rabiei A., O’Neill A.T., Neville B.P. Processing and development of a new high strength metal foam. [in] MRS Proceedings, 2004, 851(10): 517.

[4] Waag U., Schneider L., Löthman P.A., Stephani G. Metallic hollow spheres-materials for the future. Met. Powder Rep., 2000, 55(1): 29.

[5] Banhart J. Manufacture, characterisation and application of cellular metals and metal foams. Prog. Mater. Sci., 2001, 46(6): 559.

[6] Vendra L.J., Brown J.A., Rabiei A. Effect of processing parameters on the microstructure and mechanical properties of Al–steel composite foam. J. Mater. Sci., 2011, 46(13): 4574.

[7] Rabiei A., Garcia-Avila M. Effect of various parameters on properties of composite steel foams under variety of loading rates. Mater. Sci. Eng. A, 2013, 564, 539.

[8] Rabiei A., Vendra L.J. A comparison of composite metal foam’s properties and other comperable metal foams. Mater. Lett., 2009, 63(5): 533.

[9] Rabiei A., Neville B., Reese N., Vendra L. New composite metal foams under compressive cyclic loadings. Mater. Sci. Forum, 2007, 539-543, 1868.

[10] Rabiei A., O’Neill A.T. A study on processing of a composite metal foam via casting. Mater. Sci. Eng. A, 2005, 404(1-2): 159.

[11] Rabiei A., Vendra L., Reese N., Young N., Neville B.P. Processing and characterization of a new composite metal foam. Mater. Trans., 2006, 47(9): 2148.

[12] Degischer H.P., Kriszt B. Handbook of Cellular Metals: Production, Processing, Applications, 2002, Weinheim, Germany, Wiley-VCH Verlag GMBH

[13] Vendra L.J. Processing and Characterization of Aluminum–Steel Composite Metal Foams, 2008, USA, North Carolina State University, 18.

[14] Hurysz K.M., Clark J.L., Nagel A.R., Hardwicke C.U., Lee K.J., Cochran J.K., Sanders Jr T. H. Steel and titanium hollow sphere foams. [in] MRS Proceedings, 1998, 521, 191.

[15] Öchsner A., Hosseini S.M.H., Merkel M. Numerical simulation of the mechanical properties of sintered and bonded perforated hollow sphere structures (PHSS). J. Mater. Sci. Technol., 2010, 26(8): 730.

[16] Friedl O., Motz C., Peterlik H., Puchegger S., Reger N., Pippan R. Experimental investigation of mechanical properties of metallic hollow sphere structures. Metall. Mater. Trans. B, 2008, 39(1): 135.

[17] Amirjan M., Khorsand H., Khorasani M. Fluidized bed coating efficiency and morphology of coatings for producing Al-based nanocomposite hollow spheres. Int. J. Miner. Metall. Mater., 2014, 21(11): 1146.

[18] Jaeckel M., Smigilski H. Coating of Polymeric Spheres with Particles, 1988

[19] Augustin C., Hungerbach W. Production of hollow spheres (HS) and hollow sphere structures (HSS). Mater. Lett., 2009, 63(13-14): 1109.

[20] Behnam M., Golezani A.S., Lima M.M. Optimization of surface quality and shell porosity in low carbon steel hollow spheres produced by powder metallurgy. Powder Technol., 2013, 235, 1025.

[21] Behnam M., Golezani A.S., Lima M.M. The effect of size and morphology of iron powder on shell density in low carbon steel hollow spheres. Powder Metall. Prog., 2011, 11(3-4): 185.

[22] Gao Z.Y., Yu T.X., Zhao H. Mechanical behavior of metallic hollow sphere materials: experimental study. J. Aerosp. Eng., 2008, 21(4): 206.

[23] Fallet A., Lhuissier P., Salvo L., Bréchet Y. Mechanical behavior of metallic hollow spheres foam. Adv. Eng. Mater., 2008, 10(9): 858.

[24] Roy S., Wanner A., Beck T., Studnitzky T., Stephani G. Mechanical properties of cellular solids produced from hollow stainless steel spheres. J. Mater. Sci., 2011, 46, 5519.

[25] German R.M. Sintering Theory and Practice, 1996, Pennsylvania, John Wiley & Sons, The Pennsylvania State University

[26] Bretschneider F., Peter B., Brucker J. Machine and Process for Producing a Free Flowing Product with a Coat, 1999