Carol Martinez, “Low-Cost Surface Alloying of Brass to Improve Corrosion Resistance in Chlorine and Chloramine- Rich Environments”
Mentor: Pradeep Rohatgi, Materials Science & Engineering
Poster #124

Brass castings find widespread applications across various industries but often suffer corrosion, particularly in chloramine and chlorine environments common in the water industry. While alloys such as red brass and Monel offer enhanced corrosion resistance compared to yellow brass, they often come at a higher cost. This research investigated a cost-effective method of surface alloying yellow brass and copper bismuth alloy during sand casting to improve their corrosion resistance. The process involved coating the mold surfaces with metal powders before pouring the melt in the sand molds. This low-cost casting process allows the internal and external surfaces of a component to be enriched with selected alloying elements, including nickel, leaving the bulk unmodified. Surface alloying experiments were conducted both in a laboratory and industrial setting. Following the casting process, the samples underwent metallographic preparation to be analyzed through optical and electron microscopy. Analysis of the samples showed distinct surface alloyed layers of average thickness ranging from 100-300µm. SEM-EDS analysis confirmed that the surface alloyed layer was enriched with nickel, ranging from 21wt%- 62wt%. Further testing demonstrated the cast surface alloyed samples had a higher corrosion resistance than those without surface alloying.