Fabrication of Al-based bulk metallic glass by mechanical alloying and vacuum hot consolidation

The Al75Ni10Ti10Zr5 bulk amorphous alloys have been synthesized by mechanical alloying and vacuum hot pressing. The as-milled powders and hot pressed samples were examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry. The Al75Ni10Ti10Zr5 amorphous powders with a high crystallization temperature of 790 K and a large supercooled liquid region of 49 K were prepared by ball milling elemental powder mixtures for 110 h. The bulk Al75Ni10Ti10Zr5 amorphous alloy was prepared by hot pressing at 733 K for 20 min under a pressure of 3 GPa. The Kissinger analysis indicated that the bulk metallic glasses exhibit high thermal stability. The Vickers microhardness of the bulk samples is in the range of 790–850 HV. The crack paths surrounding the indents of all these samples emanate from the indent corners, indicating that the propagation of cracks occurred by radiation.