Papers by Author: Yue Mei Wang

Abstract: Mg72.5Zn26Y1.5 quasicrystal alloys were investigated under different solidification conditions. The specimens of Mg-Zn-Y alloys with cooling rates from 13.2K/s to 69.8K/s were gathered by a designed multi-channel temperature acquiring system and then the microstructures and phase evolution of the alloys were analyzed. The results show that the precipitation temperature of icosahedral quasicrystal phase (I-phase) increased with cooling rate increased from 13.2 K/s to 69.8K/s. The microstructure was mainly made up of α-Mg, I-phase and Mg7Zn3 phase. Meanwhile, the quasi-crystalline morphology was significantly different in the experiments. It changed from five (six) petals to the big pentagon with the decreased cooling rate.

Abstract: Mg72.5Zn26Y1.5 (at.%) quasicrystal alloys were investigated under different solidification conditions. The cooling curves were gathered by the multi-channel temperature acquiring system and the corresponding microstructures were analyzed. The morphology, microhardness and volume fraction of quasicrystals were detailedly studied. The effects of cooling rate on the above three aspects were also studied and the relation schema among them were exhibited. The results show that the quasicrystal size tend to smaller, its microhardness and volume fraction gradually increased, and the quasicrystal morphology changed from bulk polygon to petal-like and finally changed to plat X-shape with the elevated cooling rate from 2.3K/s to 181.2K/s. However, the quasicrystal nucleation will be restrained and amorphous matter will be created if the cooling rate exceed the critical point which make against the formation of quasicrystals with high performance.