Effect of Tool Traverse Speed on Strength, Hardness, and Ductility of Friction-Stir-Processed LM25AA-5% SiCp Metal Matrix Composites

摘要

Plates made from stir cast light metal 25 aluminum alloy–5% silicon carbide particle (SiCp) metal matrix composites (LM25AA-5% SiCp MMCs) have sub-optimum mechanical properties because of the uneven distribution of the SiC particles (SiCp) that are used as reinforcement. Currently, friction stir processing (FSP) is used as a secondary processing method to overcome the uneven distribution of particles in the aluminum matrix. The FSP method is controlled by three important parameters: tool rotational speed, tool traverse speed, and axial force. Of these three parameters, the tool traverse speed governs the mechanical properties of the MMCs. Hence, in this investigation, an attempt has been made to study the effect of tool traverse speed on the mechanical properties of friction-stir-processed material. Five different tool traverse speeds (ranging from 20 to 60?mm/min) were used to process LM25AA-5% SiCp MMC plates whose thickness was 12?mm. The tensile strength, ductility, and hardness of the friction-stir-processed material were evaluated. Microstructure and SiCp reinforcement distribution were characterized using optical and scanning electron microscopy. The tool traverse speed of 40?mm/min produced a defect-free processed zone with superior mechanical properties compared to those produced at other speeds.