Plastic deformation and fracture of quartz at atmospheric pressure

Abstract

Crystals of synthetic quartz have been strained at a compression rate of 3 × 10⁻⁴ sec⁻¹ in air at atmospheric pressure. Slip line and stress birefringence evidence is reported for plastic deformation by slip on the system (0001) [1120] at temperatures of 550°C and above. Above 700°C additional slip systems become operative. The spacings of self-made Wallner lines on fracture surfaces indicate that sources of supersonic sound exist during crack propagation at all temperatures from 25°C to 850°C.