Microstructure and mechanical properties of fine-grained TiB2/AZ31 composites prepared via powder metallurgy

In this work, the fine-grained TiB2/AZ31 composites with different TiB2 additions were successfully fabricated via powder metallurgy, which exhibited the simultaneous improvement of strength and ductility. The average grain size of these TiB2/AZ31 composites could reach below 2.5 mu m, which also achieved the low porosity and high hardness. Tensile test results indicated that AZ31-5wt%TiB2 composites exhibited the best comprehensive mechanical properties at room and elevated temperatures. The yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) of AZ31-5wt%TiB2 could reach 219 MPa, 312 MPa, and 15.5% at room temperature, while the YS, UTS, and EL at 300 degrees C increased by 18.0%, 19.5%, and 156.4% compared with AZ31. The grain refinement played a dominant role in simultaneous improvement of strength and ductility. Besides that, the fracture mechanism of the AZ31-5wt%TiB2 composites at both room temperature and elevated temperature showed ductile fracture.

Automated summary

In this study, fine-grained TiB2/AZ31 composites with different TiB2 additions were fabricated via powder metallurgy, and the simultaneous improvement of strength and ductility was achieved. Grain refinement played a dominant role in enhancing the mechanical properties of the composites.