Fracture toughness and temperature dependence of Young's modulus of a sintered albite glass

Albite glass is an important component in many ceramic compositions, often used as liquid phase during the sintering process. Nevertheless, in spite of its almost ubiquous presence in the final microstructure of these compositions, some properties such as Young's modulus or fracture toughness have not been extensively studied in literature. This paper presents an experimental study on a sintered albite glass obtained from sodium feldspar powder. The microstructure of the resultant amorphous solid was analyzed via scanning electron microscopy and X-ray diffraction. Fracture toughness was determined at room temperature from the critical stress intensity factor (K-IC) with a three point bending single-edge notched test (SENB). Young's modulus and coefficient of thermal expansion (CITE) were measured as a function of the temperature. A value of CIE of 6.6 x 10(-6) degrees C-1 within the temperature range 300-500 degrees C was found. Young's modulus values of the albite glass were within the range from 63.6 to 65.2 MPa. SENB tests revealed a fracture toughness of K-IC = 0.78 +/- 0.06 MPa m(1/2), which is of similar value to those found for borosilicate and soda-lime glasses. (C) 2012 Elsevier B.V. All rights reserved.