Effect of Layer Thickness in Selective Laser Melting on Microstructure of Al/5 wt.%Fe2O3 Powder Consolidated Parts

In situ reaction was activated in the powder mixture of Al/5 wt.%Fe2O3 by using selective laser melting (SLM) to directly fabricate aluminium metal matrix composite parts. The microstructural characteristics of these in situ consolidated parts through SLM were investigated under the influence of thick powder bed, 75 μm layer thickness, and 50 μm layer thickness in various laser powers and scanning speeds. It was found that the layer thickness has a strong influence on microstructural outcome, mainly attributed to its impact on oxygen content of the matrix. Various microstructural features (such as granular, coralline-like, and particulate appearance) were observed depending on the layer thickness, laser power, and scanning speed. This was associated with various material combinations such as pure Al, Al-Fe intermetallics, and Al(-Fe) oxide phases formed after in situ reaction and laser rapid solidification. Uniformly distributed very fine particles could be consolidated in net-shape Al composite parts by using lower layer thickness, higher laser power, and lower scanning speed. The findings contribute to the new development of advanced net-shape manufacture of Al composites by combining SLM and in situ reaction process.

[1]  Jan Bültmann,et al.  High Power Selective Laser Melting (HP SLM) of Aluminum Parts , 2011 .

[2]  P. Xiao,et al.  Mechanisms of the aluminium-iron oxide thermite reaction , 1999 .

[3]  G. Liang,et al.  The surface character and substructure of aluminium alloys by laser-melting treatment , 1997 .

[4]  B. Liu,et al.  SURFACE HARDENING OF AL BY HIGH CURRENT FE-ION IMPLANTATION , 1997 .

[5]  L. Hao,et al.  Materials and Process Aspects of Selective Laser Melting of Metals and Metal Matrix Composites:A Review(Invited Paper) , 2009 .

[6]  Joseph R. Davis.  Properties and selection : nonferrous alloys and special-purpose materials , 1990 .

[7]  G. Dirras,et al.  Microstructure of Al-Al2O3 nanocomposite formed by in situ phase transformation during Al nanopowder consolidation , 2011 .

[8]  Yifu Shen,et al.  In-situ TiC particle reinforced Ti-Al matrix composites: Powder preparation by mechanical alloying and Selective Laser Melting behavior , 2009 .

[9]  L. Hao,et al.  Experimental investigation on selective laser melting behaviour and processing windows of in situ reacted Al/Fe2O3 powder mixture , 2012 .

[10]  Á. Griger,et al.  Equilibrium and non-equilibrium intermetallic phases in Al-Fe and Al-Fe-Si Alloys , 1996, Journal of Materials Science.

[11]  A. Simchi,et al.  Effect of rapid solidification on the microstructure and mechanical properties of hot-pressed Al―20Si―5Fe alloys , 2009 .

[12]  Jyoti Mazumder,et al.  Solidification behavior and microstructural evolution during laser beam—material interaction , 1998 .

[13]  Rémy Glardon,et al.  Sintering of commercially pure titanium powder with a Nd:YAG laser source , 2003 .

[14]  K. Osakada,et al.  Rapid Manufacturing of Metal Components by Laser Forming , 2006 .

[15]  L. Hao,et al.  Effect of selective laser melting layout on the quality of stainless steel parts , 2012 .

[16]  Tom Craeghs,et al.  A pragmatic model for selective laser melting with evaporation , 2009 .

[17]  Wei-min Liu,et al.  Microstructure and properties of Fe3Al–Fe3AlC0.5 composites prepared by self-propagating high temperature synthesis casting , 2004 .

[18]  B. Cantor,et al.  Effect of semisolid microstructure on solidified phase content in 1xxx Al alloys , 2001 .

[19]  E. Lavernia,et al.  The rapid solidification processing of materials: science, principles, technology, advances, and applications , 2010 .

[20]  K. Sun,et al.  Kinetics of thermite reaction in Al-Fe2O3 system , 2006 .

[21]  L. Hao,et al.  In Situ Formation of Particle Reinforced Al Matrix Composite by Selective Laser Melting of Al/Fe2O3 Powder Mixture , 2012 .

[22]  F. Klocke,et al.  Consolidation phenomena in laser and powder-bed based layered manufacturing , 2007 .

[23]  Christopher J. Sutcliffe,et al.  Selective laser melting of aluminium components , 2011 .

[24]  B. Costa,et al.  Fe2O3/aluminum thermite reaction intermediate and final products characterization , 2007 .