Is the hardness and strength of quartz glass high?

         The mechanical properties of quartz glass are better than that of hard glass and ceramics, but the brittleness is poor. The theoretical calculation strength of quartz glass is very high, about 24*103MPa, but the actual measured strength is dozens of times lower than this value. The main factor affecting the strength is the surface defects of the glass, especially the size and depth of the surface microcracks. The flexural strength of the finely ground quartz glass sample is about 0.6 times higher than that of the rough ground sample; are inherent defects such as bubbles, impurities, uneven melting, and residual stress.

         The strength of quartz glass increases with increasing temperature, reaching greater values near the annealing temperature.

         The shear modulus, Young's modulus, damping, Poisson's ratio and failure modulus of quartz glass generally increase with the increase of temperature, while the hardness decreases with the increase of temperature.