Feasibility of Electrochemical Deposition of Nickel/Silicon Carbide Fibers Composites over Nickel Superalloys
- PDF / 1,358,514 Bytes
- 7 Pages / 593.972 x 792 pts Page_size
- 2 Downloads / 189 Views
SUPERALLOYS are widely used at medium and high temperatures, where high strength and creep resistance are needed. They exist with various compositions; however in high temperature applications, nickel superalloys are most often employed. Inconel 718 is a widely used nickel-based superalloy, accounting for a high share of the annual volume production for both cast and wrought products.[1] Due to its superior high-temperature mechanical properties, such as high yield and ultimate tensile strength, and resistance to corrosion and oxidation, it has been widely used for parts in the aerospace industry and in nuclear reactors.[2] In aircraft engines, superalloys can be used from the rear stages of the high-pressure compressor (HPC) to the low-pressure turbine (LPT). However, since they are metallic materials, they suffer from a significant stiffness reduction at high temperature,[3,4] so that the use of E.P. AMBROSIO is with the Center for Space Human Robotics @ PoliTO, Italian Institute of Technology, Corso Trento 21, 10129 Torino, Italy. M.R. ABDUL KARIM is with the Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences & Technology, Topi-23640, Pakistan. Contact e-mail: [email protected] and [email protected] M. PAVESE, S. BIAMINO, C. BADINI, and P. FINO are with the Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy. Manuscript submitted November 3, 2014. Article published online February 14, 2017 2504—VOLUME 48A, MAY 2017
composites could be envisaged in order to increase high temperature stiffness. Indeed, metal-matrix composites (MMCs) are very attractive engineering materials since their properties can be enhanced or tailored through the use of selected reinforcement.[5] However, superalloy-based composites have rarely been considered in the past,[6,7] monocrystalline or directional solidified alloys being preferred to improve high-temperature behavior.[8–10] In this work, a novel approach is proposed to increase the stiffness of nickel-based superalloys at high temperature, by superimposing a stiff composite layer produced by electrodeposition over a nickel superalloy substrate. Electrodeposition methods have been much studied in the past for the production of coatings containing reinforcing particles.[11–17] The matrix of these composite coatings is often nickel or copper, while the reinforcement is generally chosen to improve wear or corrosion resistance, even if other applications are possible. For instance low attrition surfaces can be produced by using fluorinated polymer particles. No significant modification of the well-known electrodeposition process is needed for obtaining composite coatings, since it is sufficient to suspend the particles in the deposition bath. The preparation of fiber-reinforced composites by the electrodeposition technique is rarely described in the literature.[18–21] In 1970 Divecha et al.[18] patented a method for the preparation of such materials, and in the late 70s and early 80s a few
Data Loading...
