Materials Science and Engineering A 488 (2008) 84–91 Texture and mechanical properties of cold deformed and annealed multilayer Ni base substrate tapes prepared by a powder metallurgy route P.P. Bhattacharjee a,∗ , R.K. Ray b , A. Upadhyaya c a ARC Centre of Excellence-Design in Light Metals, Deakin University, Geelong, VIC 3217, Australia b R&D Division, TATA Steel, Jamshedpur 831001, India c Department of Materials and Metallurgical Engineering, Indian Institute of Technology, Kanpur 208016, India Received 22 September 2007; received in revised form 24 October 2007; accepted 24 October 2007 Abstract An innovative powder metallurgy based technique has been investigated to fabricate multilayer tapes having configurations Ni/Ni–5 at.% W and Ni/Ni–5 at.% W/Ni for use as mechanically strong and textured substrates for coated superconductor applications. Development of cube texture ({001}〈100〉) following heavy cold rolling (∼95%) and annealing has been studied in the Ni side(s) of these multilayer tapes and this has been compared to a monolithic Ni tape. The deformation textures in the Ni side(s) of the tapes are found to be quite similar to that of monolithic Ni strained to similar level of deformation. However, the cube texture upon annealing has been found to be significantly stronger in the Ni side(s) of the multilayer tapes as compared to the monolithic Ni tape after different annealing treatments. Cross-sectional EDS analyses in form of X-ray area mapping of the multilayer tapes reveal significant diffusion of W from the alloy side to the Ni side(s). All these facts amply demonstrate the beneficial role of the alloying element W on the development of cube texture in Ni. Finally, the mechanical properties of the multilayer tapes have been evaluated to ascertain their suitability in the actual application scenario. © 2007 Elsevier B.V. All rights reserved. Keywords: Nickel alloys; Powder metallurgy; Multilayer substrate; Cube texture; EBSD 1. Introduction The rolling assisted biaxially textured substrates (RABiTS TM ) method developed at ORNL, USA is a very promising route for making highly cube textured ({001}〈100〉), long, flexible substrate tapes for coated high temperature superconductor (HTS) applications [1,2]. A necessary condition for improving the critical current densities of the superconducting tapes is to remove high angle grain boundaries which typically show the ‘weak link’ behaviour [3]. In the RABiTS TM method this is achieved by the epitaxial growth of the buffer and superconducting layers on highly cube textured metallic substrates. The sharp cube texture of the substrate material ensures the presence of grains of almost a single orientation and thus the grain boundary network consists of predominantly low angle boundaries. ∗ Corresponding author. Tel.: +61 3 5227 2112; fax: +61 3 5227 1103. E-mail address: pinaki14@yahoo.com (P.P. Bhattacharjee). Pure Ni received the initial attention for use as a substrate material due to the possibility of developing a sharp cube texture after heavy cold rolling and annealing [4]. The oxidation resis- tance of pure Ni and its small lattice mismatch with overlying buffer layers are also favourable factors for the epitaxial growth of the buffer and superconducting layers. Current densities in excess of 10 6 A/cm 2 have been reported in Ni base substrate tapes with certain buffer layer configurations [5]. To increase the engineering current density (i.e. the total current carried by the HTS film divided by the total cross-sectional area of the whole tape) the substrate thickness should be kept to a min- imum. Unfortunately, poor mechanical strength of pure Ni in annealed condition makes it difficult to prepare very thin coated Ni tapes involving a reel-to-reel deposition process of the buffer and superconducting layers. Hence, it becomes imperative to increase the mechanical strength of pure Ni through alloying addition via the solid solution strengthening mechanism. However, the addition of alloying elements and impurities in general are considered detrimental to the development of sharp cube texture. Therefore, the choice of alloying elements should 0921-5093/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.msea.2007.10.065