Effect of Y2O3 on structure and mechanical properties of SiO2-Al2O3-MgO glasses
Résumé
Silicate glasses of SiO2-Al2O3-MgO with Y2O3 doping (0~1.8%, in mass fraction) were prepared by a conventional melt quenching technique. The effect of Y2O3 doping on the mechanical properties and structural stability was investigated. The bending strength, compressive strength, and compression modulus increase, and the optical band gap decreases with the increase of Y2O3 doping when Y2O3 doping is < 1.2 %. At the Y2O3 doping of 1.2%, the optical band gap of the glass reaches the minimum value of 3.11 eV, and the bending strength, compressive strength, and compression modulus arrive to 107.48 MPa, 221.24 MPa and 117.87 GPa, respectively. Further increase of Y2O3 doping content leads to the decrease of the mechanical properties and the increase of optical band gap. The appropriate addition of Y2O3 reduces the number of non-bridging oxygen in the glass network structure, thus rejoining the isolated islands in the network structure and enhancing the bonding of the network structure and the structural stability of the glasses. However, the excessive of Y2O3 doping leads to generation of non-bridging oxygen, thus reducing the structural stability and mechanical properties of the glasses. © 2016, Editorial Department of Journal of the Chinese Ceramic Society. All right reserved.