Effect of tungsten content on dynamic compressive properties of borosilicate glass/tungsten composites at elevated temperatures

An investigation was conducted to evaluate the dynamic compressive properties of glass/tungsten composites containing 20–50 vol% tungsten at a strain rate of 3 × 10³ s⁻¹ and at elevated temperatures in the range from 450 °C to 775 °C. Results show that the tungsten particles are more uniformly distributed in the glass matrix with increasing tungsten content. The strengths of the composites decrease while the ultimate strains increase gradually together with the occurrence of the brittle-to-ductile transition with increasing testing temperature. Increasing the tungsten content from 20 to 50 vol% leads to a gradual decrease of the brittle-to-ductile transition temperature from 685 °C to 455 °C and a gradual extension of the interval between the brittle-to-ductile transition temperature and 775 °C at which all the composites lose their bearing capacity from 90 °C to 320 °C, because the tungsten phase plays a principal role in the deformation of the composite containing 50 vol% glass with the assistance of the adiabatic temperature rise caused by tungsten deformation at high strain rate while the glass matrix initiates deformation mainly for the composites with glass content over 67 vol%. The deformation is mainly undertaken by the glass phase in the 80BH/20W and 67BH/33W composites while it is shared by tungsten particles and the glass matrix in the 50BH/50W composite. The cracks are primarily initiated along the interface between the glass matrix and tungsten phase in the composites with glass content over 67 vol% resulted from the mismatched deformation between tungsten particles and the glass matrix, whereas they originate from trans-granular fracture of elongated tungsten particles in the 50BH/50W composite attributed to the participation of more tungsten particles in the deformation.