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Proceedings of the National Conference onTrends and Advances in Mechanical Engineering,YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012researchers have used compound casting to join different similar and dissimilar metallic couples such assteel/cast iron, steel/Cu, steel/Al, Cu/Al, Al/Al, and Mg/Mg, joining dissimilar light metals such as aluminumand magnesium by the compound casting process is still a relatively unexplored area. In this study, compoundcasting as an economic straightforward in situ technique was used to join dissimilar aluminum and magnesiumlight metals.Through the combination of various materials, this compound casting process can help components meet themost diverse of requirements. And with the hybrid construction process, the material bond is created by recasting– separate hot or cold bonding/jointing processes are not necessary. This in turn reduces the number ofproduction steps needed in the manufacturing process.A good example of applications in this field is the manufacturing of engine blocks. As a pure sheet steel solution,it consists of numerous individual parts which are joined to one another. In contrast, the compound castingsolution makes it possible to produce this component as a single piece. The intelligently designed casting madefrom aluminium or magnesium alloy ensures the high functional integrity of flanges and bearing carriers, forinstance.In difficult areas, a carefully positioned insert such as a semi-finished product made of steel or an aluminumalloy provides the necessary strength. In comparison with conventional die casting, the manufacture of acompound casting piece requires additional handling, for example manipulation of inserts or perhapspretreatment of the surfaces.3.1. Applications of Compound CastingCompound casting parts are already used in vehicle construction for parts of the chassis, such as the engineblock, shock strut supports and gearbox casing, as well as bodywork components, for example door frames andconnection supports and as dashboard mounts in the interior. And according to information from the automotiveindustry, multi-material components are on the increase. This is proven by compound cast parts such as the 6-cylinder magnesium engine with aluminum insert from BMW and other components which are undergoingdevelopment but have not yet been announced. The aircraft industry, too, is relying more and more on compoundcast materials.3.2. Compound Casting ProcessThe compound casting process to prepare the Al/Mg couples from commercially pure aluminum andcommercially pure magnesium are as under.In this process cylindrical inserts with 20 mm diameter and 100 mm height were machined from aluminum andmagnesium ingots. Their surfaces were ground with silicon carbide papers up to 1200 grit, then rinsed withacetone and placed within a cylindrical cavity of a CO2 sand mold with 30 mm diameter and 80 mm height. Twoseries of samples were prepared. In the first series, aluminum ingots were melted in a clay-graphite crucibleplaced in an electrical resistance furnace. The molten aluminum was cast around the magnesium inserts at 700 0 Cunder normal atmospheric conditions.In the second series, magnesium ingots were melted in a steel crucible placed in the same furnace under thecovering flux, to protect magnesium melt form oxidation. The molten magnesium was cast around the aluminuminserts at 7000 C under normal atmospheric conditions. Schematic sketches of the mold used in the castingprocess and the prepared Al/Mg couple are illustrated in Fig. 1.Figure 1 Schematic sketches of (a) the mold used for the casting process and (b) the prepared Al/Mg couple.502
Proceedings of the National Conference onTrends and Advances in Mechanical Engineering,YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 20124. Literature ReviewA lot of research material is referred to describe the insights of the compound casting process. However 10 majorpapers are selected as arranged in descending order of their year of publication in table-1. These selected papersare studied in detail so that every aspect of the process i.e. from preparation of substrate, pretreatments, pouringsystem, solidification behavior, microstructural analysis & mechanical properties can be determined.Table-1 Depicting title of papers along with year & journal in which publishedS.NOTitle of PaperYear ofPublicationName of Journal1.Dissimilar joining of Al/Mg light metals bycompound casting process2011Journal of Materials Science2.Mechanical testing of titanium/ aluminium–silicon interface: Effect of T6 heat treatment2011Materials Science and EngineeringA3.Aluminium–aluminium compound fabricationby high pressure die casting2011Materials Science and EngineeringA4.Interface formation between liquid and solid Mgalloys—An approach to continuouslymetallurgic joining of magnesium parts2010Materials Science and EngineeringA5.Effect of copper insert on the microstructure ofgray iron produced via lost foam casting2009Materials and Design6.Light metal compound casting2009Science in China7.Solidification processed Mg/Al bimetalmacrocomposite: Microstructure and mechanicalproperties2008Journal of Alloys and Compounds8.Interface formation in aluminium–aluminiumcompound casting2008Acta Materialia9.Mechanical testing of titanium/aluminium–silicon interfaces by push-out2008Journal of Materials Science10.Effect of continuous cooling heat treatmenton interface characteristics of S45C/coppercompound casting2004Journal of Materials ScienceThese selected papers are studied in detail so that every aspect of the process i.e. from preparation of substrate,pretreatments, pouring system, solidification behavior, microstructural analysis & mechanical properties can bedetermined. Table-2 depicts a detailed review of 10 papers on compound casting process or some other processeswhich are very similar to compound casting process. Outcomes of the different reviews along with testingmechanisms and few observed values are also shown.503
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Page 5 and 6: 3 Al-Al CompoundCastingusing highpr
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