Transmission electron microscopy showed that precipitates of a C-based metastable phase were coherently bound to the matrix of grade VT1-0 Ti. The Gorsky effect was observed for C in 3-point bending tests at 300 to 550C; as revealed by the reversible creep deformation. A technique was developed which permitted the determination of the diffusion coefficients of the interstitial impurities that caused the Gorsky effect. By using this technique, effective C diffusion coefficients were determined at 300 to 550C in VT1-0 Ti samples with various grain sizes. It was shown that, in fine-grained (about 0.3μm) samples, the main mechanism of C diffusion was grain-boundary diffusion. Activation energies of 103 and 177kJ/mol were determined for the grain-boundary and bulk diffusion of C, respectively.
L.S.Bushnev, L.V.Chernova, N.V.Girsova: Physics of Metals and Metallography, 2001, 92[3], 251-7
Table 271
Diffusivity of Co in Ti with Respect to the c-Axis
Temperature (C) | Direction | D (cm2/s) |
824.0 | parallel | 6.463 x 10-8 |
820.4 | perpendicular | 3.456 x 10-8 |
711.3 | parallel | 1.690 x 10-8 |
711.5 | perpendicular | 6.237 x 10-9 |
616.1 | parallel | 4.655 x 10-9 |
614.8 | perpendicular | 1.124 x 10-9 |