College - Author 1

College of Engineering

Department - Author 1

Materials Engineering Department

Degree Name - Author 1

BS in Materials Engineering

College - Author 2

College of Engineering

Department - Author 2

Materials Engineering Department

Degree - Author 2

BS in Materials Engineering



Primary Advisor

Blair London, College of Engineering, Materials Engineering Department


In a marine environment solid surfaces are subject to corrosion and fouling, which is the buildup of unwanted material such as algae and barnacles, that can impede the functionality of components. The application that this project focuses on are hydraulic cylinders. Eight alloys, including three newly developed alloys, were tested for marine fouling performance. Three of the alloys were primarily NiCr, these included Inconel 625, Metco 1720, and P105-X3. Four alloys contained varying amounts of Cu, and these were Monel 400, CuproNickel, Monel 450, and P76-X24. Finally, one sample of a Co-based alloy was also tested, Ultimet. Of the samples tested, Metco 1720, P105-X3, and P76-X24 were developed by Oerlikon Metco, a company that focuses on new alloy development, characterization, and testing. The other alloys are commercially available. The samples were immersed in the ocean at the Cal Poly Pier for nine weeks before being removed to assess how each alloy performed in a marine environment. Built up fouling was quantitatively measured by mass of fouling and surface area covered by fouling. Corrosion was assessed using mass lost to corrosion as well as visual inspection. Of the NiCr alloys, Inconel 625 was the least fouled with 0.5882g of fouling covering 28.29% of the surface, and P105-X3 was the most fouled with 1.7423g of fouling covering 48.66% of the surface. A correlation was found between amassed fouling and the presence of hard phases in the alloys. With the Cu containing alloys, the fouling resistance was largely controlled by the Cu content; more Cu resulted in better resistance to fouling. The exception was the P76-X24 with 16% Cu, which exhibited a fouling resistance equivalent to that of Monel 400 which has 30% Cu. The Ultimet was the most fouled sample with a mass of 1.7567g covering 61.23% of the surface.

Available for download on Wednesday, June 03, 2026

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Metallurgy Commons