The role of Ti in cavitation erosion and corrosion behaviours of NAB alloy in 3.5 % NaCl solution

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.…”

“…However, when the Ti content exceeded 0.478 wt%, the corrosion resistance decreased, which was attributed to the different corrosion protection ability of the passive film formed on the κ phase compared to α and β phases. 112…”

“…Therefore, the rate of crack propagation at the α/κ interface was reduced, leading to improved cavitation erosion resistance. 112…”

“…This is because the corrosion protection ability and thickness of the corrosion layer that develops on the Ti-rich κ phase differ from the oxide film forming on the α and β phases, leading to deteriorated corrosion properties of the alloy. 112 Additionally, after a three-month exposure, crevice corrosion may cause the interfacial bonding to deteriorate, reducing the uniformity of the passive film and impairing the corrosion resistance. 73…”

“…In other scenarios, the addition of Cr or a Cr-reinforced NAB composite 100 leads to the development of a corrosion product film containing chromium oxides and hydroxides, which enhances the alloy's corrosion resistance. 100,109 Similarly, the Ti addition up to 0.478 wt% 112 results in the incorporation of TiO 2 (with a high dielectric constant) into the oxide film, which also improves the corrosion-resistance of NAB. The oxide film formed upon the bronze-infiltrated binder jet additively manufactured 316 stainless steel (BJP316), contained Cu 2 (OH) 3 Cl and Sn 4 (OH) 6 Cl 2 , promoted tribocorrosion resistance by providing a lubricating effect.…”