Effect of composition, shape, and distribution of nonmetallic inclusions on the ductility and fracture of metal

1. Corundum and silicate stringers lower the high-temperature ductility of nickel in torsion tests. Evenly distributed corundum and globular silicon dioxide (≤0.2%) have a negligible effect on this characteristic. 2. Globular silicon dioxide and corundum and silicate stringers lower the high-temperature ductility of nickel slightly in tensile tests; only ≥0.2% dispersed corundum has a negative effect on this characteristic. 3. The ductility of nickel at room temperature (relative elongation and reduction in cross-sectional area) decreases with increasing concentrations of inclusions, in which case the reduction in cross-sectional area decreases more, particularly with even distribution of dispersed corundum inclusions.