TiB₂ Reinforced Aluminum Matrix Composites Prepared by Rapid Solidification and Hot Extrusion

To avoid the coarse microstructures and micro-segregation of traditional ingots affecting the improvement of material strength, a rapid solidification single-roll melt rotation method was used to prepare 5%TiB₂/Al-Zn-Mg-Cu-Zr-Er composite material ribbons, composite bars were obtained by hot extrusion at 380-440 ℃, and the microstructures and mechanical properties of TiB₂ reinforced aluminum matrix composites were studied by X-ray diffraction, scanning electron microscopy, tensile testing and other analytical methods. Results show that rapid solidification can significantly refine composite grains, microstructure uniformity, the grain size of the prepared TiB₂ reinforced composite ribbons are 4-6 μm; fine-grained composite ribbons are hot extruded to obtain bars, and TiB₂ particles are uniformly distributed. As the extrusion temperatures increase, the tensile strength of composite bars increases from 381 MPa to 445 MPa, and the grains have grown. The extrusion temperature of 420 ℃ for 30 min is the best rapid solidification and hot extrusion process parameter for preparing composites. Rapid solidification technology has great potential for grain refinement of aluminum matrix composites.