Vol.:(0123456789) 1 3 Metals and Materials International https://doi.org/10.1007/s12540-020-00801-x Efects of Mo and B Additives on Hardness and the Resistance of Cu–Ni Alloy to Wear, Corrosion and Corrosive Wear Runfang Hou 1  · Mingyu Wu 1  · Qingyang Li 2  · Wei Li 2  · D. L. Chen 3  · D. Y. Li 1 Received: 19 May 2020 / Accepted: 18 June 2020 © The Korean Institute of Metals and Materials 2020 Abstract Due to its corrosion resistance, modifable mechanical properties, and electrical conductivity, etc., CuNi alloy has found a wide variety of industrial applications, especially in the marine environment. It is highly desired if the mechanical strength and wear resistance of CuNi alloy can reach a level comparable to that of steel while keeps its corrosion resistance. In this study, efects of Mo, B, and their combinations on microstructure and performance of CuNi alloy were investigated, includ- ing formation of second phases, hardness, and resistances to wear, corrosion and corrosive wear. It was demonstrated that the Mo and B additives were efective in strengthening the CuNi alloy while maintaining reasonable corrosion resistance. In particular, the combination of Mo and B additives was more efective than a single additive to strengthen the alloy. Mo and B additives have demonstrated their great promise as new alloying elements to modify CuNi alloys. Keywords CuNi · Hardness · Wear · Corrosive wear · Molybdenum · Boron 1 Introduction Structural materials used in the marine environment are subjected to simultaneously mechanical and electrochemi- cal (corrosion) attacks [1, 2]. A mechanically strong material may perform poorly if its resistance to corrosion is low. The situation is similar when the material encounters simultane- ous wear and corrosion attacks [3, 4]. Wear is the material removal caused by dynamic contact between two surfaces, which is largely determined by the mechanical properties of the materials in contact. Although wear is a surface damage process, it can make components of machinery and facilities dysfunctional. Wear does not only cause the damage to the components, it may also lead to failure of the entire machin- ery system and generate safety issues. To possess high wear resistance, the material is generally required to have high mechanical strength or hardness. However, in corrosive environments, the electrochemical degradation may make materials largely lose their original stress-bearing capability. The mechanical-electrochemical synergistic attack to struc- tural materials is thus a main issue for the safety of mari- time transportation and ofshore oil drilling operation, which leads to huge costs for facility maintenance and replacement [5]. Diferent structural materials and anti-corrosion tech- niques are developed to improve the durability of relevant machinery and facilities with reduced costs. Due to its corro- sion resistance and modifable mechanical properties, CuNi alloy has found a wide variety of applications especially in the marine environment [6–9]. Cu alloys are electrically con- ductive and their non-sparking and non-magnetic properties make them also suitable for specifc applications under vari- ous operation conditions, e.g., oil refneries, chemical plants and underground mining [10]. The early pipeline system in the seawater environment was made of carbon steel and cast irons with relatively low costs. However, their low resistance to corrosion and fouling make the ferrous alloys performed poorly with a short service life. Copper then became the base metal for a wide range of applications in marine envi- ronment, which can be strengthened by alloying elements. Nickle is one of common alloying elements used to increase the mechanical strength and corrosion resistance of copper. The nickel addition increases the strength of copper with * D. Y. Li dongyang.li@ualberta.ca 1 Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada 2 Institute of Advanced Wear and Corrosion Resistant and Functional Materials, Jinan University, Guangzhou 510632, China 3 Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON M5B 2K3, Canada