Abstract: Effect of cooling rate on microstructure and mechanical properties of in-situ formed bulk metallic glass composites (BMGCs) Ti_40.9Zr_30.4Nb_4.2Cu₇Ni_1.7Be_15.8was studied. The BMGCs were prepared by a copper casting method, with the cooling rate of which being controlled by the sizes of BMGCs, the larger the BMGCs, the slower the cooling rate. The microstructure and the properties were characterized by XRD, SEM, DSC and universal mechanical testing machine, respectively. The results show that with the decrease of cooling rate, the dendrites are ripening and the size increases. Compression tests show that the cooling rate largely influences the compression properties of the BMGCs. The lower the cooling rate, the stronger the work hardening ability, the higher the compressive strength; and the maximum compressive strength reaches 1921 MPa, but the yield strength decreases slightly. Tensile tests show that the cooling rate does not have a significant effect on the tensile properties of the BMGCs, and the maximum tensile strength reaches 1469 MPa.

Key words: in-situ formed bulk metallic glass composites, cooling rate, compression properties, tensile properties