Microstructure study of CVD W coating on Mo single crystal rods with 〈1 1 1〉 axial orientation by EBSD

The morphology and grain orientation of the surface and the cross section of CVD W coating on a single crystal Mo rod with an axial direction of 〈1 1 1〉 have been characterized by SEM and EBSD. An obvious preferred orientation growth has been found in the W coating. About 80% surface area of the W coating is covered by W grains with a normal direction within 10° around 〈1 0 1〉. A strong {1 0 1}〈1 1 1〉 texture has also been observed in the W coating. EBSD studies suggest that a combination of the Mo matrix introducing growth mechanism and the competing growth mechanism should be responsible for the preferred growth and texture formation.