Study On Structure And Properties Of High Strength And High Modulus Glass

High strength and high modulus glass fiber has good mechanical properties,corrosion resistance,thermal stability and so on.In general,as reinforced materials,high strength and high modulus glass fiber are widely used in aerospace,transportation,wind power and other fields.High strength and high modulus glass is the foundation for preparing high strength and high modulus glass fiber.The study of the relationship between structure and properties of high strength and high modulus base glass is very important,and it is of great significance for the study of a new high modulus and high modulus base glass fiber.In this paper,the structure and properties of high strength glass fiber base glass were studied by NMR,FTIR,thermal expansion and differential scanning calorimetry（DSC）,bending strength and Young’s modulus were optimized by adjusting the glass composite.The effect of Al/Si ratio on SiO₂-Al₂O₃-MgO glass was studied.The results showed that the degree of polymerization of glass network decreased with the increase of Al/Si ratio.With the increase of Al/Si ratio,T_g and T_x of the glass increased.The thermal expansion coefficient of glass was small,at 3.41×10^-64.04×10^-6℃^-1.Bending strength was between 146.1 and 158.7 MPa,Young’s modulus was between91.9 and 95.6 GPa,and Vickers hardness was between 745.5⁷62.0 MPa.With the increase of Al/Si ratio,the bending strength and Vickers hardness decreased,while the Young’s modulus increased,and the glass sample（C3）of Al/Si=0.81 had better comprehensive properties.The effect of Ca/Mg ratio on SiO₂-Al₂O₃-MgO-CaO glass was studied.The results showed that with the increase of Ca/Mg ratio,the degree of polymerization of glass network structure firstly weakened and then increased.The thermal expansion coefficient of glass and T_g decreased firstly and then increased with the increase of Ca/Mg ratio,while T_x and T_g increased firstly and then decreased,and the turning point was Ca/Mg=0.22.The bending strength was between 132.1¹45.2 MPa,Young’s modulus was between 92.8⁹4.9 GPa and Vickers hardness was between 725.3⁷77.5MPa.As the Ca/Mg ratio increased,density and bending strength decreased firstly and then increased,while Young’s modulus and Vickers hardness decreased.The upper limit of crystallization temperature decreasesd gradually,which was conducive to the drawing of glass fiber.When Ca/Mg=0.67（C6）,it had the best effect.The effect of B₂O₃ on SiO₂-Al₂O₃-MgO-CaO glass was studied.Research showed that B₂O₃ existed outside the network as network modifiers.The addition of B₂O₃leaded to a decrease in the glass degree of polymerization.The crystallization peak temperature T_p increased with the increase of B₂O₃ content,and the glass transition temperature T_g decreased gradually.With the increase of B₂O₃ content,the softening temperature of glass decreased gradually,which was beneficial to the glass fiber drawing operation.With the increase of B₂O₃ content,the density of glass decreased gradually,which was conducive to the lightweight of composite materials.Bending strength of glass was between 112.9¹22 MPa,Young’s modulus was between86.6⁹0.2 GPa and Vickershardness is between 699.3⁷11.2 MPa.And they all decreased with the increase of B₂O₃ content.When adding B₂O₃ is 2 mol%,B₂O₃ has better effect on optimizing the drawing process of glass fiber.