Influence of particulate B4C size on microstructural evolution and mechanical behavior in nanostructured Al matrix during heat treatment

We reported the influence of particle size (micro-B 4 C and nano-B 4 C) on microstructural evolution and mechanical properties in nanostructured Al matrix during heat treatment. The results indicated the incorporation of nano-B 4 C could significantly inhibit the grain growth of Al during heat treatment. The segregation layer in Al/B 4 C interface increased after heat treatment for all the composites samples. High density of Guinier-Preston (GP) zones and platelet η' could be observed in grain interior of all samples, while some coarse η phases (MgZn 2 ) could be only detected in grain boundaries of AA7075 alloys and the composites with micro-B 4 C. The yield strength of the composites with the incorporation of nano-B 4 C could reach up to 958 ± 28 MPa after heat treatment, which could be ascribed to the Hall-Petch strengthening and dislocation strengthening.