Use and Perspective of X-Ray Diffraction in Science and Technology of Ceramic Coatings
X-ray diffraction provides a major tool to investigate the relation between the properties of a coating/substrate composite and its microstructure. Stresses, compositions, stress-depth profiles and composition-depth profiles can be determined. Further, microstructural parameters as crystallite size and microstrains can be obtained. The role of the penetration of X-rays deserves special attention, in particular when analysing thin coatings.
In various CVD TiC coating/substrate systems the strain (and stress) can be predicted quantitatively from thermal shrinkage. In some of these systems stress relaxes partially by strain-accommodating processes either in the layer and/or in the substrate.
In commercial CVD coatings foreign elements can be present either in solid solution or as a second phase and these can significantly influence the microstructure and (mechanical) properties.
In the surface (compound) layer of nitrided steels both stress and composition depth profiles occur. The stress profile is caused by the thermal shrinkage and by the composition-depth profile. Partial strain accommodation occurs due to the presence of pores.
KeywordsNitride Layer Stress Profile Thermal Shrinkage Nitrided Steel Composition Depth Profile
Unable to display preview. Download preview PDF.
- 1.H. P. Klug and L. E. Alexander, “X-ray Diffraction Procedures for Polycrystalline and Amorphous Materials, 2nd Ed., John Wiley & Sons, New York (1974).Google Scholar
- 3.R. Delhez, Th. H. de Keijser, and E. J. Mittemeijer, “The role of X-ray diffraction analysis in surface engineering; investigation of the microstructure of nitrided iron and steels”, Surf.Eng. 3: 331–342 (1987).Google Scholar
- 4.H. C. F. Rocendaal, P. F. Colijn, and E. J. Mittemeijer, “Morphology, composition and residual stress of compound layers of nitrocarburized iron and steels”, Surf. Eng. 1: 30–42 (1985).Google Scholar
- 5.F. Bollenrath, V. Hauk, and E. H. Müller, “Zur Berechnung der vielkristallinen Elastizitätskonstanten aus den Werten der Einkristalle”, Zeit. Metallkunde 58: 76–82 (1967).Google Scholar
- 6.H. C. F. Rozendaal, “The Influence of Nitriding on the Microstructure and Stress State of Iron and Steel”, Ph. D. thesis, Delft (1985).Google Scholar
- 7.M. G. Moore and W. P. Evans, “Mathematical corrections for stress in removed layers in XRD residual stress measurements”, SAE Trans. 66: 340–345 (1958).Google Scholar
- 8.W. G. Sloof, H. J. M. Rijpkema, R. Delhez, Th. H de Keijser, and E. J. Mittemeijer, “Prediction and measurement of compressive and tensile stresses in coatings of TiC and TiN chemically vapour deposited on various substrates”, Surf. Eng. 3: 59–63 (1987).Google Scholar
- 1l.M. Hendriks, “X-ray Diffraction Study of Polycrystalline Silicon Layers”, Ph. D. thesis, Delft (1985).Google Scholar
- 12.M. A. J. Somers and E. J. Mittemeijer, in preparation.Google Scholar