Sliding of copper [001]-twist grain boundaries detected by shear deformation of liquid B2O3 particles on the grain boundaries Original Research Article

From a Cu–0.065mass%B solid solution alloy, bicrystals having [001]-twist grain boundaries with various misorientation angles were prepared by the Bridgman method. Cu bicrystals containing B2O3 particles were made from the bicrystals by internal oxidation treatment. The Cu–B2O3 bicrystals were tensile tested at high temperatures, where B2O3 particles become liquid. The amount of grain-boundary sliding was measured from the amount of shear deformation of the liquid B2O3 particles on a sliding grain boundary. Shear deformation of voids where the B2O3 particles was embedded was also utilized to measure the amount of grain-boundary sliding. The temperature and misorientation-angle dependence of the grain-boundary sliding is discussed for the Cu–B2O3 bicrystals. Since the liquid B2O3 particles easily deform at high temperatures, the measured amount of grain-boundary sliding is considered to reflect the inherent nature of the Cu [001]-twist grain boundaries. Using the present method of measurements, up to 2 μm grain-boundary sliding can be measured with an accuracy of about 0.1 μm.