Preparation Process of Cast Infiltrated Self-exothermic Ceramic Particle Precursors
Author of the article:YU Wenzhen 1 , WANG Yiran 1 , GAO Yimin 1 , SHI Qingfeng 2 , GAO Shangjun 2
Author's Workplace:1. State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an 710049 , China; 2. China Railway Baoji Bridge Group Co., Ltd., Baoji 721006, China
Key Words: metal matrix composites; self-exothermally active powders; casting precursor
Abstract:
Wear phenomenon primarily occurs on the surface of materials, making the localized strengthening of the surface crucial for improving wear resistance. Typically, ceramic particles are employed as reinforcing agents to design and create precursors. Metal matrix composites are then formed through the casting infiltration method, achieving the desired localized strengthening. Previous studies have demonstrated that the introduction of self-exothermic powders into precursors enhances the casting quality of composites. This paper investigates the preparation process of a cast and infiltrated self-exothermic ceramic particle precursor, considering factors such as the type and amount of precursor binder, as well as the dosage of self-exothermic powder. The results indicate that the occurrence of the exothermic reaction is unaffected by the organic binder PVAL and the inorganic binder sodium silicate. However, the inorganic binder water glass is more suitable for the cast infiltration method. The inclusion of 5%(mass fraction) powder leads to noticeable absence of powder coverage on some particle surfaces, while a 20% dosage results in uneven mixing in the reaction layer, causing violent exothermic reactions and the formation of more voids. The best-performing precursor is prepared using 10%(mass fraction) Al-ZnO active powder and 1 g∶1 mL sodium silicate as a binder.