Moscow, 3 August 2026 – RUSAL, one of the world's largest aluminium producers, has developed a new aluminium alloy for the electrochemical protection of the underwater hulls of marine vessels and port infrastructure. The AP5M alloy responds to the growing industry demand for superior corrosion protection.
RUSAL’s R&D Department developed the AP5M alloy and secured a patent for it from the Russian Federal Service for Intellectual Property (Rospatent).
In aggressive environments such as seawater, the AP5M alloy forms an electrochemical anode-cathode pair with the structure it protects, such as a vessel’s submerged hull or port infrastructure. The pair generates a continuous low-level electrical current, giving the protected structure a negative electrical potential and thereby preventing electrochemical corrosion. Such aluminium alloys also protect oil and gas pipelines.
The AP5M alloy offers a practical current capacity exceeding 2,580 Ah/kg, delivering superior protection. It also resists passivation, preventing the formation of an insulating oxide film that can reduce current output. Despite relatively expensive alloying additives, including zirconium, titanium, gallium and indium, the alloy matches the price of existing alternatives, offering customers a cost-effective option. Its higher current capacity also enables either a longer service life at the same product weight or reduced metal consumption while maintaining the required level of protection.
Within RUSAL, the Volgograd Aluminium Smelter (VgAZ) manufactures protector products. The plant launched production in 2020 and has since become a leading supplier in the Russian market.
“Increasingly stringent requirements from the country’s port operators drove the development of this new alloy. Its predecessors, the AP4N and AP4NM alloys, developed in Russia between 2005 and 2010, no longer deliver the high performance modern protector systems demand,” Alexander Belotelov, Managing Director of the Volgograd Aluminium Smelter, said.