Microstructure and mechanical properties of AZ91/TiP magnesium matrix composite ribbons fabricated by melt-spinning

• For the first time, magnesium matrix composite ribbons were reinforced with micron-sized Ti particles and prepared by rapid solidification. • Using a lower solidification rate (1.54516 × 105 °C/s) increases the thickness of the rapidly solidified ribbons, reduces the proportion of columnar crystals, and makes it have more fine equiaxed crystals, making it have more stable properties. • According to previous research, AZ91 alloy was selected as the matrix based on the reaction between Ti and Al; and the interface compound was formed and the grains were refined by rapid solidification to improve the performance. • After adding a small amount of Ti particles, the grains are further refined, YS and UTS are significantly improved, and EL is slightly reduced. Under standard tensile samples (non-micromechanics), YS;UTS and EL are 186 MPa, 318 MPa, and 8.73 %. There are few studies on the preparation of magnesium matrix composites (MMCs) by rapid solidification. This study aims to add minor amounts of Ti particles to AZ91 alloy and prepare AZ91/Ti P MMC ribbon by Melt-Spinning (MS). The effects of Ti particle content on the microstructure and mechanical properties of AZ91/Ti P ribbon were studied by scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), X-ray diffraction (XRD), transmission electron microscopy (TEM), three-dimensional profiling (3D-P) and calculation of supercooling rate. The results show that the grain refinement of AZ91 ribbon prepared by rapid solidification is very significant and the grain refinement is further improved with the increase of Ti particle content; at the same time, the growth of β-Mg 17 Al 12 is inhibited, and the interface reaction between Ti and Mg leads to the formation of interfaces around Ti particles. These nano-scale Ti 3 Al and Al 3 Ti interface compounds uniformly wrap the Ti particles. It is believed that the addition of Ti particles not only helps to refine the surrounding grains, but also increases the dislocations in the MMC ribbon and forms a good interface, thereby improving the mechanical properties. Compared with AZ91 alloy ribbon, the yield strength and tensile strength of MMC material containing 5 wt.% Ti particles increased by 25.0 % and 22.7 % respectively. The elongation only decreased by 10.9 %. AZ91/5 wt.% Ti P ribbon has a better balance between high strength and high elongation. The analysis shows that the strengthening effect of this mechanical property is mainly attributed to fine grain strengthening, dislocation strengthening and non-basal slip. The AZ91/Ti MMC material was synthesized through vacuum stirring casting; MMC ribbons were prepared by melt spinning at a lower undercooling rate; microscopic analysis and mechanical property testing revealed that rapid solidification can refine the grains; further refinement of the grains occurred after adding a small amount of Ti particles; and interfacial compounds like Ti 3 Al and Al 3 Ti formed at the Ti/Mg interface effectively reduce stress concentration and pinning, contributing to the enhancement of mechanical properties.