Corrosion and erosion are an interrelated phenomenon where the rate of erosion can increase in a more corrosive geothermal environment. To reduce erosion and corrosion rate effectively, materials can be substituted with costly corrosion-resistant materials or coated the ordinary material with more noble alloys. In this paper, erosion, and corrosion of Powder Metallurgy Hot Isostatically Pressed (PM HIPed) nickel-based alloy (UNS N06625) and grade 5 titanium-based alloy (UNS R56400) materials with SiC and TiB2 additives respectively were tested in wells HE-23 and HE-56 located at Hellisheidi geothermal site. The samples were tested in a geothermal fluid at 194°C and 12.6 bar gauge in well HE-23 and 198°C and 13.9 bar gauge in well HE-56 with H2S, CO2 and SO4 as the main corrosive species. Intergranular cracks in PM HIPed UNS N06625-10v.%SiC and transgranular cracks in PM HIPed UNS R56400-10v.%TiB2 were observed. The results and analysis of this paper will contribute to the selection and feasibility estimation of using PM HIPed UNS N06625-10v.%SiC and UNS R56400-10v.%TiB2 materials for high-value parts manufacturing to be used in the corrosive geothermal environment.