Symposium Review: Metal and Polymer Matrix Compositesat MS&T 2013

NIKHIL GUPTA1,3 and MURALIDHARAN PARAMSOTHY2,4

1.—Composite Materials and Mechanics Laboratory, Department of Mechanical and AerospaceEngineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA. 2.—Depart-ment of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1,Singapore 117576, Singapore. 3.—e-mail: ngupta@nyu.edu. 4.—e-mail: mpsothy@yahoo.co.uk

This article reflects on the presentations made during the Metal and PolymerMatrix Composites symposium at Materials Science and Technology 2013(MS&T’13) held in Montreal (Quebec, Canada) from October 27 to 31. Thesymposium had three sessions on metal matrix composites and one session onpolymer matrix composites containing a total of 23 presentations. While theabstracts and full-text papers are available through databases, the discussionthat took place during the symposium is often not captured in writing and getsimmediately lost. We have tried to recap some of the discussion in this articleand hope that it will supplement the information present in the proceedings.The strong themes in the symposium were porous composites, aluminummatrix composites, and nanocomposites. The development of processingmethods was also of interest to the speakers and attendees.

What an exciting event Materials Science andTechnology 2013 (MS&T’13) was! And the sympo-sium too! Rapid developments in the field of com-posite materials are difficult to keep pace with byscanning the huge volume of literature that is beingpublished. Small, focused meetings provide oppor-tunities for dialogue and discussion about the cur-rent state and future outlook in various subareas ofcomposite materials. The Metal and Polymer MatrixComposites symposium broadly covered the fields ofmetal matrix composites (MMCs) and polymer ma-trix composites (PMCs) in three and one sessions,respectively. The discussion range spanned thewhole spectrum including processing methods,characterization methods, mechanical properties,thermal properties, and applications. Porous com-posites and aluminum matrix composites were thecentral themes of the MMC sessions.

Porous composites present an important area ofresearch. In an innovative approach, the reinforce-ment may be selectively removed to yield a matrixhaving an ordered interconnected pore network. Inthe presentation titled, ‘‘Steel wires in Ti and NiTimatrices: From reinforcements to microchannels’’by David Dunand of Northwestern University andco-workers, it was observed that carburized steelwires did not excessively react with the Ti and NiTi

matrices and were sacrificially corroded from themetallic matrix to yield a regular three-dimensional(3-D) interconnected pore network. The electrode-position method can be used to yield semiporouscomposite coatings. In the presentation titled,‘‘Electrodeposition of zinc/ceria nanocompositecoatings’’ by Ioic Ebbrayat of La Rochelle Universiteand co-workers, it was observed that nickel additionconverted the structure of deposited zinc from plate-like to nodular, which minimized the deposition ofceria nanoparticles on sharp edges. Such an ap-proach improved the nanoparticle dispersion in theas-deposited coating.

Porous composites also include hollow-particle-filled metallic matrices called syntactic foams. A setof papers discussed processing, properties, applica-tions, and multifunctionality in syntactic foams.The presentation titled, ‘‘Hollow particle filledlightweight composites: Weight saving potential inengineering applications’’ by Nikhil Gupta of NewYork University explained a method of simulta-neously tailoring the mechanical and thermalproperties of syntactic foams to obtain multifunc-tionality in these composites. This generalizedmethod can be used for both polymer and metalmatrix syntactic foams. The opportunities presentin these porous lightweight composites are immense

JOM

DOI: 10.1007/s11837-013-0853-3� 2014 The Minerals, Metals & Materials Society

and can be very beneficial for automotive applica-tions. In the presentation titled, ‘‘The making andmechanical performance of metal powder injectionmoulded iron and steel matrix syntactic foams,’’Dirk Lehmhus of University of Bremen and his co-workers observed that increasing the hollowmicrosphere content also increased the energyabsorption during compression. The high meltingpoint of steel is a major challenge for synthesizingsteel matrix syntactic foams, but their powderinjection molding process can provide high-qualitycomposites. The presentation titled, ‘‘Aluminum-flyash composites produced by powder metallurgyprocessing’’ by Shankar Sastry of Washington Uni-versity-St. Louis discussed the beneficial effects offly ash inclusion into the aluminum alloy. Theirgroup used precipitator fly ash particles, which is anindustrial waste material, to develop lightweightcomposite materials. Porous precipitator fly ashparticles can reinforce aluminum and reduce thedensity of the composite.

Apart from the porous composites containingaluminum matrix, several other presentations werefocused on aluminum matrix composites. Compos-ites are extensively used in structural applications.In the presentation titled, ‘‘Trimodal aluminumnanocomposites’’ by Julie Schoenung of Universityof California—Davis, B4C particles of different sizeswere incorporated into aluminum alloy matricesusing cryomilling. The B4C particle presence wasobserved to be detrimental to the matrix ductilitybut significantly beneficial toward increasingstrength. Furthermore, as the B4C particle size de-creased to nanoscale, nanograin (for increasingstrength) and micrograin (for increasing ductility)regions were observed in the matrix to result inultrahigh-strength composites. In the presentationtitled, ‘‘A fabrication technique for MMCs withshape memory alloy reinforcement’’ by Glenn Beanof University of Florida and co-workers, shape-memory alloy reinforcement was incorporated intoaluminum alloys to improve strength as well asimpart self-healing characteristics. Significantinterdiffusion between the shape-memory alloyreinforcement and metal matrix was observeddepending on the processing temperature used. Inthe presentation titled, ‘‘Characterisation ofAl-AC8H/Al2O3p MMCs produced by stir castingroute’’ by Anne Zulfia of University of Indonesia andco-workers, the relative weakening of aluminumalloy using ex situ added Al2O3 microparticles wasobserved, likely due to particle clustering and en-trapped porosity. Their results indicated theimportance of wetting and dispersion of reinforce-ment in the matrix. In the presentation titled,‘‘Exploring the role of hydrostatic pressure on yield,deformation and fracture of infiltrated ceramicparticle reinforced metals’’ by M. Gabriella Taran-tino of Ecole Polytechnique Federale de Lausanneand coworkers, the effect of hydrostatic pressure (inrelation to defense or deep sea applications) on the

mechanical behavior of melt-infiltrated aluminum/alumina composites was discussed. In the presen-tation titled, ‘‘On the effects of zinc and AlB2 par-ticles on absorbed impact energy of aluminummatrix composites’’ by Fernando Reyes of Univer-sity of Puerto Rico—Mayaguez and co-workers, theductility-enhancing effect of dissolved zinc andductility-compromising effect of boron on aluminumwere discussed. In the presentation titled, ‘‘Dia-mond composites. The new generation of heat sink’’by Javier Narciso of Alicante University and co-workers, the effect of precursor-substrate contacttime on Al4C3 formation and consequent thermalconductivity variation was investigated for Al/dia-mond composites. Diamond composite films haveexcellent thermal conductivity while possessing acoefficient of thermal expansion (CTE) close to thatof silicon wafer.

Magnesium is now competing with aluminum inautomotive applications. In the presentation titled,‘‘Nano aluminium and magnesium matrix compos-ites’’ by Mirle Surappa of Indian Institute of Tech-nology-Ropar and co-workers, the excellent strength-ening effect of in situ formed and well-dispersedceramic nanoparticles (from pyrolyzed polymer pre-cursors) in magnesium as well as aluminum matriceswas investigated and discussed. Magnesium isexpected to substitute for aluminum in some appli-cations to develop even lighter composites, and re-search in magnesium matrix composites is rapidlyincreasing. Another presentation dealt with magne-sium matrix composites. In the presentation titled,‘‘Processing and characterization of magnesium ma-trix composites for functional applications’’ by CarlosLeon-Patino of Universidad Michoacana and co-workers, AlN preforms squeeze infiltrated with AE42magnesium alloy showed simultaneous improve-ment in strength as well as thermal conductivity.Better wettability of the alloy melt on AlN with timewas also observed.

In the presentation titled, ‘‘Titanium based metal-matrix composites via in situ nitridation’’ by Sou-mya Nag of University of North Texas and co-workers, the strengthening effect of large nitrogensolubility in Ti-Mo and Ti-V alloys was investigated.The in situ fabrication methods can be cost-effec-tive.

Two presentations specifically discussed newprocessing methods. In the presentation titled,‘‘Laser deposited in situ TiC reinforced nickel ma-trix composites: Microstructure and tribologicalproperties’’ by Rajarshi Banerjee of University ofNorth Texas, the laser-engineered net shaping(LENS) method was used to synthesize in situ TiCand graphite interpenetrating 3-D networks withinthe Ni matrix. The consequent self-lubricatingproperties of the nickel matrix composites wereinvestigated and related to the 3-D network micro-structure formed in situ. In the presentation titled,‘‘Fabrication of MMCs via spark plasma sinteringfor nuclear energy application’’ by Indrajit Charit of

Gupta and Paramsothy

University of Idaho and co-workers, tungsten andtungsten CERMET materials with a fine grainstructure (as dispersion fuels for nuclear applica-tions) were sintered using spark-plasma sintering.The main driving force in this approach was thatCERMET materials using fine-grained tungstenhave much better fuel-retention capability than thecoarse-grained structure counterpart.

Fibers are an important type of reinforcements forcomposites. In the presentation titled, ‘‘Probing themicroscopic strength of metal composite reinforce-ments’’ by Goran Zagar of Ecole PolytechniqueFederale de Lausanne and co-workers, the generaldecohesion mode of failure in fiber composites, aswell as fiber strength increasing with decreasingfiber diameter was observed. The fibers are studiedfor characteristics that are important for reinforcingMMCs.

Composites often undergo dynamic loading. In thepresentation titled, ‘‘Multi-resolution modeling ofthe dynamic loading of MMCs’’ by Remi Dingrevilleof Sandia National Laboratories and co-workers,multiresolution modeling was used to dissect thedynamic loading characteristics of composite mate-rials. Development of modeling and simulation toolsfor composite materials can help in developing pre-dictive capabilities that lead to efficient materialand microstructure design.

In polymer composites, the reduction of debond-ing is vital for high strength. In the presentationtitled, ‘‘Elastic inhomogeneities in fiber tows of atextile polymer composite via inelastic light scat-tering’’ by Michael Aldridge of University of Michi-gan and co-workers, fiber tow elasticityinhomogeneities leading to potential debondingwere investigated. Environment-induced weakbonds may also form between polymer laminatesduring processing, potentially leading to inferiormechanical properties. In the presentation titled,‘‘Quantitative percussion diagnostics for evaluating

‘Kiss’ bonds between composite laminates’’ by ScottPoveromo of University of California—Irvine andco-workers, such weak bonds were characterizedand evaluated.

Polymer nanocomposites are an important class ofmaterials. In the presentation titled, ‘‘The transientthermal stability of polymer nanocomposites duringlaser pulse heating’’ by Karen Supan of NorwichUniversity and co-workers, the positive effect ofceramic nanoparticle and/or carbon nanotube pre-sence on increased thermal stability during pulsedlaser heating was investigated. The ceramic-richlayer helps in increasing the thermal stability ofnanocomposites. In the presentation titled, ‘‘Inclu-sion of carbon nanotubes into the polystyrene ma-trix’’ by Muralidharan Paramsothy of NationalUniversity of Singapore, the nanotube dispersion,nanotube-polymer interface, and nanotube align-ment in a polystyrene matrix were characterizedand discussed. Contemporary composite researchalso involves the use of composites in functional(nonstructural) applications. The development ofnew high-performance and low-cost polymers isimportant for composite materials. In the presen-tation titled, ‘‘Synthesis of geopolymers using flyash precursors’’ by Shankar Sastry and co-workers,the systematic conversion of fly ash to geopolymerwas discussed. Such polymers derived from anindustrial waste materials present new opportuni-ties for recycling of waste materials and develop-ment of low-cost polymers.

Overall, the scope of the composites field contin-ues to widen as indicated by the presentations andthe follow-up discussions. From the traditionalstructural applications, composites are evolving intomultifunctional materials that are valuable inthermal energy management, surface protection,and nuclear fuel applications. The development ofnew processing methods is helping both MMC andPMC fields.

Symposium Review: Metal and Polymer Matrix Composites at MS&T 2013