Effects of Ti and Be addition on microstructure and mechanical properties of Mg58.5Cu30.5Y11 bulk metallic glass
(School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870, China)
Abstract: Based on the Mg58.5Cu30.5Y11 alloy, 10% Ti, 10% Be and 10% Ti70Be30 (mole fraction) were respectively added to the alloy and samples with a diameter of 3 mm were fabricated by conventional Cu-mold casting method. The phase constituent, thermal stability and microstructure of the alloys were investigated by using X-ray diffraction, differential scanning calorimetry and scanning electron microscopy, respectively. The effects of alloying elements Ti and Be on the microstructure and mechanical properties of Mg58.5Cu30.5Y11 alloy were discussed. The results show that CuTi phase is distributed in (Mg0.585Cu0.305Y0.11)90Ti10 and (Mg0.585Cu0.305Y0.11)90(Ti0.7Be0.3)10 alloys, while CuYBe glassy phase containing CuY crystals is embedded in the matrix of (Mg0.585Cu0.305Y0.11)90Be10 alloy. Under uniaxial compressive loading, the largest compressive fracture strengths for (Mg0.585Cu0.305Y0.11)90Ti10, (Mg0.585Cu0.305Y0.11)90Be10 and (Mg0.585Cu0.305Y0.11)90(Ti0.7Be0.3)10 alloys are 797.6, 952.6 and 1007.8 MPa, respectively, and the strengths are increased by about 17%, 40% and 48% compared with Mg58.5Cu30.5Y11 alloy. The strength reliability for the three alloys is much improved according to the strength distribution region of 10 samples of each alloy.
Key words: Mg-based alloy; alloying element; Ti; Be; microstructure; strength reliability