DIFFRACTION PATTERN INDEXING AND THE EFFECT OF METAL-ION IMPLANTATIONON KAPPA-ALUMINA

The X-ray diffraction pattern of kappa-Al2O3 in the form of a coating over a Ti(C,N) interlayer has been indexed up to the 204 peak in terms of the hexagonal super-lattice of the orthorhombic unit cell. The lat tice parameters have been derived using silicon as standard of referen ce; some peak overlaps were present. The coating is characterized by l ow residual stress with a strong shear stress component, and a low str ain distribution; this was not quantified. After a dual metal ion impl antation with Ti and Ni, the residual stress in the kappa-Al2O3 was en tirely removed, and the lattice parameters were measured as a=0.9624 n m and c=O.8908 nm. In addition, the intensity of the diffraction peaks was reduced to about 85% and the strain distribution of the 002, 200 and 201 peaks increased. It is thought that these effects are due to s urface amorphization and the development of a dislocation substructure , respectively.