Study on friction behavior and wear resistance mechanism of different screw materials during homogenization of LFP/NCM battery slurries

SUS304 steel is widely employed as the core component material in battery slurry homogenization equipment. However, due to its insufficient hardness and poor resistance to plastic deformation, severe abrasive wear and oxidative corrosive wear tend to occur during the homogenization process, which further deteriorates the battery performance. In this work, targeting the special medium of battery slurry, three potential screw materials for application in battery slurry systems were selected: 40Cr alloy steel, 440C martensitic stainless steel, and GCr15 bearing steel. The friction behavior laws and wear resistance mechanisms of these materials in lithium iron phosphate (LFP) and lithium nickel cobalt manganese oxide (NCM) slurries were systematically investigated using an atmosphere friction and wear tester. The results demonstrate that all three materials exhibit superior wear resistance compared to SUS304. Among them, the chromium-rich hard phase in 440C delivers excellent anti-wear properties, making it suitable for medium-to-high speed homogenization, especially with outstanding performance in LFP slurry. GCr15 possesses a uniform and stable phase structure composed of carbides and martensite, resulting in broader adaptability to various working conditions. It maintains an extremely low wear rate ( δ ) with minimal fluctuation in both slurries, and the reduction in δ exceeds 90% under high-speed and high-load conditions, revealing the optimal comprehensive performance. This work provides important theoretical basis and experimental support for material selection of key components in battery homogenization equipment, and is of positive significance for improving equipment reliability and ensuring the quality of battery slurry.