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5 Copperwires withdiameters of0.4, 1, and 2mm intopolystyrenepatterns,followed bypouring ofgray ironmelt.6 Al-Al,Al-Mg(a)AlMg1/AlSi7(b)AlMg1/AlCu7Lost foamcasting(LFC)processCompoundCastingwithZincateprocessand ZngalvanizingProceedings of the National Conference onTrends and Advances in Mechanical Engineering,YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012substrate and AJ62 magnesiumcast alloy (as well as 99.98%pure Mg) was achieved.• The coating material has only aminor influence on thecompounds’ microstructure andmechanical properties• The melted copper wire dissolvedin the gray iron matrix up toabout 0.9 wt.% and the copperexceeding the limits of solubilitywas dispersed throughout thematrix. Some copper particlessegregated at the bottom of themold due to their high specificgravity.• The graphite morphology inreference sample (without copperinsert) was type A flakes. Insamples containing copper wire,graphite type changed to B, D orE flakes depending on theexperimental variables.• When the copper insert wascompletely or extensively melted,type D or E flake graphite formedin the specimen due to the highundercooling during eutecticsolidification.• When the copper insert was notmelted or was partially melted,type B flake graphite appearedinside the Wire Affected Zonearound the copper wire, due torather high undercooling duringeutectic solidification.• Different metallic or non-metallicmaterials in the form of wire,particles, and so on, can beinserted into the polystyrenepatterns during pattern makingstage of lost foam castingprocess. This procedure can beutilized for in-mold alloying,production of bi-metal andcomposite materials, study ofinterface between the matrix andthe insert, and investigation ofreaction phases formed at theinterface.• Through adequate surfacetreatments and coatings, theAlMg1 substrate’s wettabilitywas improved in a way that thecouples of Al–Al and Al–Mgwere successfully produced.• Interfaces showed very low (Al–Mg) to no (Al–Al) formation ofIMPs, and other defects, such asoxide inclusions, contraction• Optical microscopy.• Scanning electronmicroscopes (SEM)coupled with anenergy dispersivespectroscopy (EDS)system• Electron microscopy• EDX investigations• Optical micrographs• Diffusionsimulations usingDICTRA software506
7 Mg shell andAl coreDisintegrated meltdeposition(DMD)methodand toppouringfollowedby hotcoextrusion8 Al-Al CompoundCastingProceedings of the National Conference onTrends and Advances in Mechanical Engineering,YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012cavities or cracks.• The combined coating of zincatetreatment and electrolyticallydepositedzinc for Al–Alcompounds offers majoradvantages compared to otherapproaches to joining lightmetals.• The zincate treatment is the mostimportant process step also forsurface preparation of thesubstrate for Al–Mg compounds.This treatment is followed byelectrolytic deposition of an Mnlayer of several micronsthickness to protect the substratefrom liquefaction by the Mgmelt, without sacrificing toomuch of wettability.• A thin layer of IMPs formsduring couple production, whichmight affect mechanical integrity.Keeping this interface thin is apossible way to improve thecompound’s properties.• Mg/Al macrocompositecontaining Mg shell and Al corecan be synthesized using acombination of DMD methodand top-pouring, followed by hotcoextrusion.• Mg based macrocompositecontaining Mg shell and Al coreis thermally more stable thanmonolithic Mg, due to fairlyuniform Al volume fraction andmechanical interlocking at theinterface.• Millimeter length scale Alreinforcement in Mg improvesstiffness and significantlyincreases failure strain and workof fracture of Mg while 0.2%YSand UTS are compromised.• Couples of AlMg1 substrate andvarious Al alloys weresuccessfully produced by meansof a laboratory-scale compoundcasting process.• A combination of pre-treatmentsand Zn coatings drasticallyenhanced wettability of thesubstrate, generating defect-freeinterfaces.• The combined coating of zincatetreatment and electrolyticallydeposited Zn offers majoradvantages compared to other• Olympusmetallographicmicroscope.• Hitachi S4300 fieldemissionscanningelectron microscope(FESEM).• Image analysis usingScion software.• Interfacial integritywas observed usingFESEM coupledwith energydispersive X-rayspectroscopy (EDS).• The coefficients ofthermal expansion(CTE) using anautomatedthermomechanicalanalyser.• Optical microscopy.• Glow dischargeoptical spectroscopy(GDOS)• One-dimensionaldiffusionsimulationsperformed usingDICTRA software.Microhardnessmeasurement.xc507
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