The Zr62.55Cu17.55Ni9.9Al10 bulk metallic glass(BMG) was prepared by using copper-mold suction-casting.X-ray diffraction and differential scanning calorimetry were utilized to determine its structure and thermal stability.Uniaxial compression and Rockwell indentation tests were adopted to study the plastic deformation behavior at room temperature.The results show that the glass transition temperature and the onset temperature of exothermic reaction of the BMG are 651.5 and 748 K,respectively.During the compression test,the BMGs undergo an engineering strain of about 2.5%,i.e.,true strain of 2.8%,and then fracture.The BMGs deform via the formation and propagation of shear bands.Under indentation loading,the BMGs deform through the formation of radiation-like and circular shear bands.The circular shear bands form earlier than the radiation-like ones.The formation mechanism of shear bands in the BMGs was analyzed and discussed.
A Fe61Co10Zr5W4B20 bulk metallic glass (BMG) with a diameter of 2 mm was prepared by using copper mould suction casting. The X-ray diffraction (XRD), differential scanning calorimetry (DSC), micro-hardness and compression tests were adopted to investigate the structure, thermal stability, especially, the effect of heat treatment on the micro-hardness and compression strength of this BMG. The BMG exhibits micro-hardness of about 1 207 Hv and compression fracture strength of about 1 707.6 MPa. After being annealed below the onset of crystallization temperature, the micro-hardness almost keeps constant. But after being annealed above the peak of crystallization temperature, the micro-hardness increases firstly and then declines gradually with the elongation of annealing time. However, annealed for the same period of time, the micro-hardness will increase with the rise of annealing temperature, while the compression fracture strength will apparently decrease.
