Effect of Ti on Microstructure, Mechanical Properties and Corrosion Behavior of a Nickel-Aluminum Bronze Alloy

Abstract

Nickel-aluminum bronze (NAB) alloys are suitable, in cast condition, to be used in marine propellers due to its excellent behavior avoiding erosion and cavitation as well as corrosion. A complex microstructure, intrinsic to this copper base system, is the result of a well-controlled chemical composition. There are few works related to the effect of adding small quantities of specific chemical elements on NAB alloys properties. The aim of this paper is to study the effect of Ti on the microstructure, mechanical properties, and corrosion behavior of a particular NAB alloy, CuAl10Fe5Ni5 (C95500), and the comparison to the Ti-free NAB alloy. Although the as-cast microstructure is very similar for both materials, the addition of only 120 ppm Ti leads to a significant grain refinement that plays a key role on the mechanical properties. It has been observed an increase in both microhardness and nanohardness as well as in the resultant Young moduli values, meanwhile no significant impact on the corrosion susceptibility has been observed.

A review of the corrosion behavior of conventional and additively manufactured nickel–aluminum bronze (NAB) alloys: current status and future challenges

“…109 In addition to modifying the chemical composition of the alloy surface for better corrosion performance, the addition of alloying elements to the bulk material can also influence its corrosion behavior. For example, while the addition of a small quantity of Ti was found to have no significant effect on the corrosion response of NAB alloy, 111 higher content of Ti up to 0.478 wt% 112 as well as Cr addition 110 contributed to better protection performance of the oxide film formed on the alloy.…”

“…These findings were supported by various corrosion tests, as well as surface analysis using X-ray photoelectron spectroscopy (XPS). 109 In addition to Ni 108 and Cr, 109 other alloying elements [110][111][112] have been studied for their effect on the corrosion resistance of NAB. For Cr addition, it has been reported that a higher amount of Cr can improve the electrochemical corrosion resistance, although these findings were not corroborated using surface analyses and other experiments.…”

“…For Cr addition, it has been reported that a higher amount of Cr can improve the electrochemical corrosion resistance, although these findings were not corroborated using surface analyses and other experiments. 110 In the case of Ti, 111 it was initially found that the addition of 120 ppm Ti had no noticeable effect on the corrosion behavior of the alloy. However, in a later study, 112 it was discovered that the addition of Ti up to 0.478 wt% was effective in diminishing corrosion.…”

Quantitative Analysis of Silicon Influence and Deformation Impact on the Mechanical and Corrosion Characteristics of Nickel Aluminium Bronze (NAB) Alloy

“…Through rigorous testing, we aim to establish a clear relationship between the silicon variation and the alloy tensile strength, ductility and hardness with respect to the deformation percentage. Corrosion resistance is another crucial property for materials used in marine environments, where the presence of saltwater can lead to rapid degradation of materials (Poorjary et al, 2023;Rivero et al, 2021). The role of silicon in improving the corrosion resistance characterization of NAB alloy is a focus of ongoing research.…”

Enhancing microstructure and mechanical properties of nickel aluminium bronze alloy through tin addition

“…This refinement is particularly beneficial in reducing crack propagation along coarser K I and K II phase boundaries. Furthermore, the introduction of titanium as a dopant has shown promise, leading to improved mechanical characteristics and the formation of finer grains in NAB alloys 9 . Notably, the addition of tin to brass has resulted in the emergence of a new phase, thereby enhancing the alloy's hardness through microstructural alterations 10 .…”