Microstructure and Mechanical Properties of Cu50Zr42Al8 Bulk Metallic Glass

摘要

Microstructure of Cu50Zr42Al8 tapered sample was characterized with X-ray diffraction, differential scanning calorimetry and optical microscopy. Surface amorphous region, center more crystalline region and transition region between the two exist under different cooling rate, respectively. The critical diameter of the bulk glassy alloy for Cu50Zr42Al8 is up to 4.8mm. The φ4mm BMG exhibits high compressive fracture strength of 2260MPa with elastic srtain of 2.0% and plastic strain of 0.4%. The mechanical properties of Cu50Zr42Al8 bulk metallic glass and its composite containing CuZr and CU10Zr7 crystallizing phases were also discussed. The φ5mm BMG composites exhibits a combination of high compressive fracture strength (1849MPa) and yielding strength (1670MPa) with elastic strain of 1.6% and plastic strain of 1.9%, the final fracture behavior of which is controlled by competition of the two crystallizing phases.