Preparation and Evaluation of Mechanical Properties of 6061Al–B₄C_p Composites Produced via Two-Stage Melt Stirring

Abstract

The present work aims at producing 6061Al metal matrix composites reinforced with 5 and 7wt% of B₄C particulates at temperature of 750°C via melt stirring method involving two-step additions. In order to improve wettability and to avoid agglomeration of B₄C particulates, K₂TiF₆ halide salt in the ratio of 0.2 were mixed with B₄C particulates and the mixture were being dropped into the melt batch wise (twice). The prepared composites were characterized by scanning electron microscopy (SEM)/energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) studies. SEM microphotographs revealed homogeneous dispersion of B₄C particulates without agglomeration in 6061Al matrix. Indexing of the XRD peaks confirmed the presence ofα-Al, B₄C and minor phases like Al₃Ti and Al₃BC. Presence of Al₃Ti phase as confirmed by XRD and EDX studies is clear indication of Ti compound/layer formed around the B₄C particles. Further, improvements in mechanical properties like hardness, tensile and compression strengths of the 6061Al matrix were obtained in the composites.

Keywords:

• Casting
• Density
• Diffraction
• Interfaces
• Low-temperature
• Micro-hardness
• Microstructure
• Properties
• Reactions
• Reinforcement
• Salt
• Tensile

Notes

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/lmmp.