ANOMALOUS X-RAY DIFFRACTION FROM ω PARTICLES IN Ti-15Mo ALLOY

Anomalous X-ray diffraction measurements were performed on a metastable beta titanium alloy (Ti-15 wt% Mo) containing thermodynamically metastable omega phase particles. The dependence of diffracted intensity on primary beam energy was measured for selected omega and beta diffraction maxima for energies near the MoK absorption edge (20.0 keV). The main focus of the paper is the interpretation of diffuse scattering around the measured beta peak. A simulation which qualitatively interprets the observed phenomenon is presented. The proposed model shows that elastic deformation of the beta matrix results from both the difference in specific volumes of omega and beta phases and a "cloud" of higher Mo content around each omega particle.