Stability and formation ability of Fe-based bulk metallic glasses under high pressure

Stability and formation ability of the Fe61Co7Zr10Mo5W2B15 and Fe(7)4Al(4)Sn(2)P(12)B(4)Si(4) bulk metallic glasses were investigated by using in situ high-temperature and high-pressure x-ray diffraction measurements with synchrotron radiation. The results reveal that the Fe61Co7Zr10Mo5W2B15 bulk metallic glass has highly thermal stability, and crystallization occurs when heating temperature is 1073 K under high pressure of 7 GPa. The crystallization temperature is at least 100 K higher than that from DSC measurements at ambient pressure. But the Fe(74)Al(4)Sn(2)Pi(2)B(4)Si(4) bulk metallic glass exhibits a low crystallization temperature during heating under high pressure of 7 GPa. The nanocrystals for the alloys were obtained when quenching in situ the alloy melts to room temperature under a high pressure of 7 GPa. Compared with the Zr-based bulk glass forming alloys, which can be cooled under high pressure to a bulky glassy state at very low cooling rates, our results seem to indicate that the Fe-based alloys have an intrinsic glass forming ability lower than the Zr-based alloys.