Nitrogen Ions Implantation in W-Based Quad Alloy: Structure, Electrical Resistivity, Surface Roughness and Vickers Hardn
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Nitrogen Ions Implantation in W‑Based Quad Alloy: Structure, Electrical Resistivity, Surface Roughness and Vickers Hardness as a Function of Ion Dose Muhammad Zakria Butt1 · Dilawar Ali2 · Muzamil Aftab1 · Farooq Bashir3 · M. Shahid Pervaiz1 · M. Usman Tanveer1 · M. Waqas Khaliq1 Received: 8 June 2020 / Accepted: 17 August 2020 © The Korean Institute of Metals and Materials 2020
Abstract Five W-alloy specimens, containing 8.57% Ni, 6.34% Cu, and 1.34% Mo, were bombarded with 5.2 MeV singly charged nitrogen ions. The ions dose range was 5 × 1014–1 × 1016 ions/cm2. XRD patterns portrayed diffraction peaks of pure W as well as of Cu0.4W0.6, MoNi4, and Ni4W phases. Harris analysis showed that the preferentially oriented planes depend on the nitrogen ions dose. The structural parameters, namely lattice strain and crystallite size, vary with nitrogen ions dose alike. Same pattern is followed by surface hardness and electrical resistivity. The increase in the values of all the parameters with ions dose is rapid in the range 0–1 × 1015 ions/cm2 and later on slow till the maximum ions dose 1 × 1016 ions/cm2. However, the interdependence of each parameter on the other ones was linear. Surface roughness of the specimens was found to decrease on increasing ions dose. On the other hand, surface hardness registers a rise as crystallite size increases, and hence follows Inverse Hall–Petch relation. Keywords W-alloy · N+1 ions implantation · Structural analysis · Electrical resistivity · Scanning electron microscopy · Surface hardness
1 Introduction It is well established that nitrogen implantation in metals, alloys, and composite materials can modify their surface properties [e.g. 1–8]. The main features of interest are surface hardness, resistance to wear, friction coefficient, fatigue resistance, crystallite size, corrosion performance, and formation of chemical compounds, etc. Yabe et al. [1] implanted thirteen 99.9% pure metals (Cu, Al, Ni, W, Fe, Nb, Ta, V, Co, Mo, Sn, Ti and Zr) with 150 keV nitrogen molecular ions using doses of 3 × 1017and 1 × 1018 ions/cm2. The surface layers of the implanted metals * Muhammad Zakria Butt [email protected] 1
Centre for Advanced Studies in Physics, GC University, Lahore 54000, Pakistan
2
Department of Physics, GC University, Lahore 54000, Pakistan
3
Central Research Laboratories, LCW University, Lahore 54000, Pakistan
were analyzed by means of RBS and XRD techniques. For the smaller 3 × 1017 ions/cm2 dose, the implanted layer of target metals was nitrided only to some extent. In Ta, V, Ti and Zr target metals, solid solution formation occurred together with an isotropic expansion of the lattice of V and Ta (cubic metals) and an anisotropic c-direction expansion in Ti and Zr lattice (hexagonal metals). When the implanted region was saturated with nitrogen, the nitride formed was quite stable. The quantity of nitrogen retained in the target metal increased whereas the heat of formation of the nitride decreased. The amount of nitrogen retained was a function of t
