Brass alloys contain the dangerous element lead. Material engineering is carried out to reduce the lead element in brass alloys and add nickel elements as a substitute for lead elements by the casting process. The phenomenon analyzed in this study explains comparing the accuracy level of OES and EDX test results on nickel dissolution in brass casting, especially in adding nickel elements. So that researchers can compare the decrease in the percentage of nickel element composition in the OES test results. At the same time, there is an increase in nickel element composition in the EDX test results. The brass dissolution process uses an electric furnace with an initial temperature of 526 °C. Elemental nickel was introduced into brass solution and dissolved elemental nickel at 978 °C for 120 min for a variation of 1 %, 2 %, 3 %, and for 180 min for a variation of 4 %. The composition of alloying elements is tested using OES and EDX. The dissolution process of brass with the addition of nickel elements tested with OES decreased from 1 % nickel elements to 0.650 %, 2 % to 1.630 %, 3 % to 2.046 %, and 4 % to 2.810 %.
Meanwhile, from the EDX test results, there was an increase in the composition of nickel elements from nickel 1 % to 1.41 %, 2 % to 2.57 %, 3 % to 3.41 %, and 4 % to 4.49 %. Brass alloys with nickel elements added decreased due to slag produced during the dissolution process of nickel elements in molten brass from the test results using OES. EDX testing results in an increase in the percentage of nickel elemental composition. The results of the OES test validation of the mechanical properties of adding nickel elements to brass alloys can be considered because the material's strength is still under the reference UNS C89550. This research contribution resulted in an effective and efficient test method with OES to analyze the elemental composition in brass alloys to which nickel elements have been added