Novel integration of boundary effect model and volume fraction for evaluating fracture toughness of SiCp/6061Al.

To investigate the effect of volume fraction (VF) on the fracture properties of silicon carbide particle-reinforced 6061 Al matrix composites (SiC p /6061Al), we propose a model for calculating the grain size G and establish a boundary effect model (BEM) that incorporates the VF of SiC p. To validate the rationality of the proposed BEM, three-point-bending tests are conducted at three different temperatures on SiC p /6061Al with three distinct VFs of SiC p. The comparisons show that the calculation results of the proposed BEM are highly consistent with those obtained in accordance with American Society for Testing Materials (ASTM) standards. Our findings reveal that both the tensile strength and fracture toughness of SiC p /6061Al decrease with an increase in VF of SiC p , whereas these properties increase with rising temperature. Fracture analysis indicates a mixed fracture mode, encompassing reinforcement fracture, matrix fracture, and interface debonding. This study provides theoretical support and data references for understanding the influence mechanism of VF of SiC p on the fracture properties of SiC p /6061Al, thereby facilitating the design and optimization of these advanced materials. • A novel model for calculating the grain size G of SiC p /6061Al. • BEM considering the volume fraction of SiC p. • Three-point-bending tests at 17 °C, 60 °C and −60 °C. • BEM results are highly consistent with those of the ASTM. • Fracture toughness decrease with the increase of VF of SiC p. [ABSTRACT FROM AUTHOR]