Effect of uniaxial load on the sintering behaviour of 45S5 Bioglass® powder compacts

The effect of a uniaxial compressive load on the sintering behaviour of 45S5 Bioglass® powder compacts was investigated by means of sinter-forging. In comparison to free sintering, densification kinetics was enhanced and the degree of crystallization was reduced. Significantly lower sintering temperatures, i.e. 610 °C instead of 1050 °C, can be employed to obtain dense Bioglass® parts when sintering is performed under uniaxial load. The effect of mechanical loading on microstructure (pore density, shape and orientation) is discussed. The results of the investigation are relevant in connection with the development of sintered Bioglass® substrates for bone replacement devices, where both porosity and crystallinity of the part require careful control and low densification temperatures are sought.