ABSTRACT

Figure 31 Energy-release rate and physical properties versus temperature [2,132]. (Courtesy of John Wiley, New York.)

to vary with concentration as C-~I2. By increasing the tin content from 0.0004% to 0,(>06%, the velocity decreased by 1/1000. The activation energy increased from 62.8 kllmol at 0.0001 % Sn to 43 kcal/mol at 0.001 % Sn. In the case of special orientation relationships, the impurity segregation to grain boundary was minimal and the activation energy was not affected by the solute content (in the range of 0.0005-0.02%) and was measured to be about 25 kl/mo!. Solutes with lower solubility limits tend to drastically reduce grain-boundary mobilities.