Nano-scale Solute Partitioning in Devitrified Bulk Metallic Glass

Abstract

Bulk metallic glass (BMG) exhibits exceptional mechanical and magnetic properties and therefore have been a subject of extensive research. Partial crystallization or devitrification of BMG results in a novel microstructure, with a large number of nano-scale crystalline precipitates evenly distributed in a glassy matrix. These high density (1023-1024 m3) crystalline precipitates are known to impede the propagation of shear bands and it is tempting to exploit them to improve the mechanical properties of BMG alloys [2-4]. To this end, it is essential to establish the fine-scale structure of the crystalline precipitates. Here, we report an experimental study of a multi-component BMG alloy, Zr52.5Cu17.9Ni14.6Al10Ti5 [5-11] using a set of complementary experimental techniques: a new wide field of view atom probe [12] equipped with a high repetition pulsed laser and in-situ small angle scattering by high-energy synchrotron x-ray. The new atom probe instrument revealed nano-scale solute partitioning at an unprecedented detail. This level of detail is crucial for understanding the interference peaks observed in small angle x-ray and neutron scattering experiments [8-11], a mystery that has lingered for more than a decade.