Microstructures and properties of AlZnMgCu alloys refined by nano AlTi-TiB-AlN-TiN/Al inoculant ribbons.

Nano AlTi-TiB-AlN-TiN/Al inoculant ribbons containing a large number of evenly distributed nanoparticles, such as AlTi (sized about 300 nm), TiB (sized about 100 nm), AlN (sized about 150 nm), and TiN (sized about 200 nm), were prepared by vacuum rapid quenching furnace to refine AlZnMgCu alloys. The nano AlTi-TiB-AlN-TiN/Al inoculant ribbons showed an excellent inoculant effect, which modified the dendrite crystals to equiaxed crystals and refined the grains from 122 ± 4 µm to 36 ± 5 µm by the addition of 0.3 wt% nano AlTi-TiB-AlN-TiN/Al inoculant ribbons. In addition to nano AlTi and TiB particles, nano AlN and TiN particles also have a certain orientation relationship with α-Al, which suggests that these particles possess nucleation potency to α-Al. After inoculation with 0.3% nano AlTi-TiB-AlN-TiN/Al inoculant ribbons, the ultimate tensile strength, yield strength, and average microhardness of the AlZnMgCu alloys increased from 246 MPa, 79 MPa, and 112 HV to 319 MPa, 100 MPa, and 136 HV, or by 29.7%, 26.6% and 21.4%, respectively.