The effect of cooling rate on the plasticity of amorphous metal

• Appropriate cooling rate is a key parameter to prepare plastic amorphous metal.
• There are two kinds of mechanism to explain the plasticity of amorphous metal.
• Appropriate morphology of crystalline phases is a one mechanism.
• Phase separation is another mechanism.

The deficient plasticity is one of the largest barriers for the application of amorphous metal as structural materials. In this article, how to improve the plasticity of amorphous metal by means of adjusting the cooling rate was discussed in detail. The experimental samples were prepared by high vacuum die-casting with Zr53.2Ti13.8Cu8.9Ni5.6Be13.5Nb5 (at. %) and Zr41.2Ti13.8Cu12.5Ni10 Be22.5 (at. %). And then the plastic samples were compared with the common amorphous samples from perspective of preparation parameters and microstructure. The relationship among mechanical properties, cooling rate and microstructure was discussed so as to discover the essential microstructural mechanism of plasticity of amorphous metal. As for Zr53.2Ti13.8Cu8.9Ni5.6Be13.5Nb5 alloy whose critical cooling rate is higher, the morphology of crystalline phases can be adjusted by changing the cooling rate to improve its plasticity. As for Zr41.2Ti13.8Cu12.5Ni10 Be22.5 alloy whose critical cooling rate is lower, phase separation which can be obtained by controlling the cooling rate would be an effective method to get amorphous metal with high plasticity. In other words, appropriate cooling rate is a key important parameter to make the brittle amorphous metal into ductile materials.

How to choose appropriate cooling rate during preparation of amorphous metal is very important in order to make the brittle metallic glass obtain high plasticity. The microstructure of crystalline phases or phase separation can be adjusted to improve the mechanical properties for different amorphous metal by changing the cooling rate.Figure optionsDownload as PowerPoint slide