Structural evaluation and mechanical properties of nanostructured A1/B_4C composite fabricated by ARB process

摘要

Nanostructured Al/B_4C composites with an average grain size of 151 nm were successfully fabricated in the form of sheets, by using accumulative roll bonding (ARB) process. Furthermore, monolithic Al (without B_4C particles) also was processed by the same method for comparison. The microstructure of the composites, evaluated by optical and scanning electron microscopy, revealed the properly distributed B_4C particles in the Al matrix. The grain size of the Al matrix, after the final ARB cycle, is studied using Williamson-Hall analysis of X-ray diffraction (XRD) pattern of the deformed sample. Mechanical properties of the specimens were investigated by tensile and hardness tests. The tensile strength and microh-ardness of the processed samples increased with increasing the number of ARB cycle. Whereas, the elongation dropped abruptly at the first cycle; afterwards, it remained nearly constant in the monolithic samples and increased slightly in the composites.