@article{LaquaiGouraudMuelleretal.2019,
  author    = {Laquai, Rene and Gouraud, Fanny and M{\"u}ller, Bernd Randolf and Huger, Marc and Chotard, Thierry and Antou, Guy and Bruno, Giovanni},
  title     = {Evolution of Thermal Microcracking in Refractory ZrO2-SiO2 after Application of External Loads at High Temperatures},
  series = {Materials},
  volume    = {12},
  journal   = {Materials},
  number    = {7},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1996-1944},
  doi       = {10.3390/ma12071017},
  pages     = {15},
  year      = {2019},
  abstract  = {Zirconia-based cast refractories are widely used for glass furnace applications. Since they have to withstand harsh chemical as well as thermo-mechanical environments, internal stresses and microcracking are often present in such materials under operating conditions (sometimes in excess of 1700 °C). We studied the evolution of thermal (CTE) and mechanical (Young's modulus) properties as a function of temperature in a fused-cast refractory containing 94 wt.\% of monoclinic ZrO2 and 6 wt.\% of a silicate glassy phase. With the aid of X-ray refraction techniques (yielding the internal specific surface in materials), we also monitored the evolution of microcracking as a function of thermal cycles (crossing the martensitic phase transformation around 1000 °C) under externally applied stress. We found that external compressive stress leads to a strong decrease of the internal surface per unit volume, but a tensile load has a similar (though not so strong) effect. In agreement with existing literature on β-eucryptite microcracked ceramics, we could explain these phenomena by microcrack closure in the load direction in the compression case, and by microcrack propagation (rather than microcrack nucleation) under tensile conditions.},
  language  = {en}
}