CuNiAl

Fabrication of Al/Ni/Cu composite by accumulative roll bonding and electroplating processes and investigation of its microstructure and mechanical properties Ali Shabani, Mohammad Reza Toroghinejad n , Ali Shafyei Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran a r t i c l e i n f o Article history: Received 5 June 2012 Received in revised form 4 August 2012 Accepted 6 August 2012 Available online 10 August 2012 Keywords: Al–Ni–Cu composite Accumulate roll bonding Electroplating Mechanica l properties Microstructure a b s t r a c t Al–Ni–Cu composite was produced using accumulative roll bonding (ARB) and electroplating processes. Nic kel was elect roplat ed on copper subst rate for a cer tain time and voltage. In this stu dy, the microstructural evolution and mechanical properties of the Al–Ni–Cu composite during various ARB cycles were studied by optical and scanning electron microscopes, microhardness, tensile and bending tests. It was observed that at first, nickel layers and then copper layers, were necked, fractured and distributed in aluminum matrix as accumulative roll bonding cycles were increased. Finally, after 11 cycles of ARB process, a completely uniform composite was produced with a homogeneous distribution of copper and nickel particles in aluminum matrix. The results showed that by increasing the number of ARB cycles, the bending strength of produced composite was increased. Also, it was found that when the number of cycles was increased, not only elongation was increased but also the tensile strength of the comp osite was impro ved. Microhar dnes s for diffe rent elements in diffe rent cycles was also eval uated . Final ly, fractu re surfa ces of samp les were studied, using scan ning electron micros copy (SEM), to reveal the failure mechanism. & 2012 Elsevier B.V. All rights reserved. 1. Intr oduc tion Metal matrix composites (MMCs) have played a great part in the mat eri als used in ind ust ry for the las t severa l decad es. Aluminum based metal mat rix composites, because of their spe cific prope rti es such as low densi ty, goo d electr ica l and thermal conductivity, wear resistance and good formability, are commonly used in aerospace, automotive and structural indus- tries [1,2]. Accumulative roll bonding (ARB) is one kind of severe plastic deformation (SPD) process which can produce bulk ultra- fine /nanog rai ned (UF G) met all ic mat eri als and met al mat rix composites [3,4]. Also, it should be noted that the majority of the severe plastic deformation processes require expensive tools and complex processes, limiting their commercial and industrial usages. However, accumulative roll bonding process can be used as a new and suitable way for producing multi-layer composites, because of its simplicity and cheaper manufacture process [5,6]. Accumulative roll bonding involves stacking two sheets of the same materials after proper annealing and surface treatments and rolling to a reduction of 50%. The rolled sheet is cut into two equal halves and this cycle is repeated as many times as needed [6,7]. It had been known that during ARB process, the imposed severe plastic deformation results in grain refinement and subdivision from high-angle boundaries to low-angle ones; then the ultra-fine grains wit h more equ ilibrium grain bou ndaries are formed finally [8]. Most ly, duri ng co-d efor mati on of dissimilar layered metal systems, plastic instabilities in one of layers happen earlier than others due to differences in mechanical properties; as strain increases, the harder layer starts necking and early fragmentation occurs between other layers [9–11]. Lots of wor ks have bee n per for med to pro duc e dif fer ent composites using accumulative roll bonding process, such as, Al/ Zn [12], Al/Cu [13], Al/Mg [14], Mg/Al/Zn [15], Ti/Al/Nb [16] and Al/Ni [5,17]. Also, studies have been done on particle reinforced metal matrix composites, including Al/Al 2 O 3 [18,19], and Al/SiC [20]. Recently, Jamaati and Toroghinejad produced a metal matrix composite (aluminum/alumina), using a coating method (anodiz- ing) and accumulative roll bonding process. The most important advantage of using coating is producing high-strength and highly unifo rm comp osites with ultra fine grain struc ture [21]. With regard to pervious works, the most incentive behind this study is to combine the goo dness of per vio us wor ks [5,13,17,21] to produce a composite with a proper distribution of reinforcement in matrix and also good mechanical properties from aluminum, copper and nickel. Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/msea Materials Science & Engineering A 0921-5093/$- see front matter & 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.msea.2012.08.017 n Corresponding author Tel./fax : þ98 311 3915726. E-mail addresses: ali.shabani@ma.iut.ac.ir (A. Shabani), toroghi@cc .iut.ac.ir (M.R. Toroghine jad), [email protected] (A. Shafyei). Materials Science & Engineering A 558 (2012) 386–393

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CuNiAl