OBRABOTKA METALLOV

Introduction. Thermal expansion is an important thermal and physical characteristic of materials, showing its expansion when heated. Knowing this property is important both from a scientific point of view and for practical applications. Materials with low thermal expansion are widely used in electronics, thermal barrier coatings and other applications. Mismatch in thermal expansion between different materials can lead to thermal stress on contact surfaces. The in-situ synchrotron X-ray diffraction method can detect this mismatch. Thermal stress requires an analysis of the coefficient of thermal expansion. Bulk expansion behavior is observed in thermally sprayed coatings. The CTE is important for designing and predicting coating performance under thermal stresses. Changes in the KTE can cause cracking and degradation of the coating. In-situ X-ray diffraction analysis helps to understand thermal expansion, crystallite size and stress and strain variation with temperature change. The aim of this work is to interpret and use in-situ high temperature X-ray diffraction as an effective tool to study the thermal mismatch behavior of a W-Co alloy substrate (8 % w/w Co, WC — matrix) with CrN, ZrN and CrZrN multilayer coatings and the characteristic differences between single component coatings and its combination in a multilayer coating. Research Methodology. In this work, specimens of chromium and zirconium nitride coatings deposited on W-Co hard alloy substrates were investigated. The fundamental method in this work is in-situ analysis using synchrotron radiation. The lattice parameter as a function of cycling temperature, the coefficient of thermal expansion during heating and cooling, and the thermal expansion mismatch between the substrate-coating pair and the coating layers in the multilayer coating were evaluated. Results and discussion. The lattice parameters and thermal expansion of the coatings are investigated. The lattice parameter of all coatings decreased during thermal cycling, indicating nitrogen evaporation. The multilayer coating has the least change in the parameter, possibly due to diffusion barriers. Lattice distortions do not differ between single and multilayer coatings. All coatings exhibit thermal expansion similar to the substrate. The multilayer coating creates conditions for compressive stresses in one phase and tensile stresses in the other phase, so the lifetime of multilayer coatings is expected to be high.

1. Krishnan R.S., Srinivasan R., Devanarayanan S. Theory of thermal expansion of crystals. Thermal expansion of crystals. Pergamon Press, 1979, ch. 3, pp. 54–104. DOI: 10.1016/B978-0-08-021405-4.50008-1.

2. Roy R., Agrawal D.K., McKinstry H.A. Very low thermal expansion coefficient materials. Annual Review of Material Science, 1989, vol. 19, pp. 59–81. DOI: 10.1146/annurev.ms.19.080189.000423.

3. Padture N.P., Gell M., Jordan E.H. Thermal barrier coatings for gas-turbine engine applications. Science, 2002, vol. 296, pp. 280–284. DOI: 10.1126/science.1068609.

4. Wang C., Yang J., Huang W., Zhang T., Yan D., Pu J., Chi B., Li J. Numerical simulation and analysis of thermal stress distributions for a planar solid oxide fuel cell stack with external manifold structure. International Journal of Hydrogen Energy, 2018, vol. 43, pp. 20900–20910. DOI: 10.1016/j.ijhydene.2018.08.076.

5. Bejarano M.L., Valarezo A., Lara-Curzio E., Sampath S. Dilation behavior of thermal spray coatings. Journal of Thermal Spray Technology, 2019, vol. 28, pp. 1851–1866. DOI: 10.1007/s11666-019-00927-4.

6. Tao S., Yang J., Shao F., Zhao H., Zhong X., Zhuang Y., Sheng J., Ni J., Li Q., Tao S. Atmospheric plasma sprayed thick thermal barrier coatings: Microstructure, thermal shock behaviors and failure mechanism. Engineering Failure Analysis, 2022, vol. 131. DOI: 10.1016/j.engfailanal.2021.105819.

7. Kustov S., Golyandin S., Sapozhnikov K., Vincent A., Maire E., Lormand G. Structural and transient internal friction due to thermal expansion mismatch between matrix and reinforcement in Al-SiC particulate composite. Materials Science and Engineering: A, 2001, vol. 313, pp. 218–226. DOI: 10.1016/S0921-5093(01)00971-6.

8. Khor K.A., Dong Z.L., Gu Y.W. Plasma sprayed functionally graded thermal barrier coatings. Materials Letters, 1999, vol. 38, pp. 437–444. DOI: 10.1016/S0167-577X(98)00203-1.

9. Öztürk B., Topcu A., Cora Ö.N. Influence of processing parameters on the porosity, thermal expansion, and oxidation behavior of consolidated Fe22Cr stainless steel powder. Powder Technology, 2021, vol. 382, pp. 199–207. DOI: 10.1016/j.powtec.2020.12.072.

10. Loghman-Estarki M.R., Shoja Razavi R., Edris H., Pourbafrany M., Jamali H., Ghasemi R. Life time of new SYSZ thermal barrier coatings produced by plasma spraying method under thermal shock test and high temperature treatment. Ceramics International, 2014, vol. 40, pp. 1405–1414. DOI: 10.1016/j.ceramint.2013.07.023.

11. Khan M.A., Anand A.V., Duraiselvam M., Rao K.S., Singh R.A., Jayalakshmi S. Thermal shock resistance and thermal insulation capability of laser-glazed functionally graded lanthanum magnesium hexaluminate/yttria-stabilised zirconia thermal barrier coating. Materials (Basel), 2021, vol. 14. DOI: 10.3390/ma14143865.

12. Purushotham N., Parthasarathi N.L., Babu P.S., Sivakumar G., Rajasekaran B. Effect of thermal expansion on the high temperature wear resistance of Ni-20%Cr detonation spray coating on IN718 substrate. Surface and Coatings Technology, 2023, vol. 462. DOI: 10.1016/j.surfcoat.2023.129490.

13. Kaschel F.R., Vijayaraghavan R.K., Shmeliov A., McCarthy E.K., Canavan M., McNally P.J., Dowling D.P., Nicolosi V., Celikin M. Mechanism of stress relaxation and phase transformation in additively manufactured Ti-6Al-4V via in situ high temperature XRD and TEM analyses. Acta Materialia, 2020, vol. 188, pp. 720–732. DOI: 10.1016/j.actamat.2020.02.056.

14. Meng Q.-K., Xu J.-D., Li H., Zhao C.-H., Qi J.-Q., Wei F.-X., Sui Y.-W., Ma W. Phase transformations and mechanical properties of a Ti36Nb5Zr alloy subjected to thermomechanical treatments. Rare Metals, 2022, vol. 41, pp. 209–217. DOI: 10.1007/s12598-021-01744-x.

15. Shiman O.V, Skippon T., Tulk E., Daymond M.R. Strain evolution in Zr-2.5 wt% Nb observed with synchrotron X-ray diffraction. Materials Characterization, 2018, vol. 146, pp. 35–46. DOI: 10.1016/j.matchar.2018.09.022.

16. Qian L.H., Wang S.C., Zhao Y.H., Lu K. Microstrain effect on thermal properties of nanocrystalline Cu. Acta Materialia, 2002, vol. 50, pp. 3425–3434. DOI: 10.1016/S1359-6454(02)00155-6.

17. Daymond M.R. Internal stresses in deformed crystalline aggregates. Reviews in Mineralogy and Geochemistry, 2006, vol. 63, pp. 427–458. DOI: 10.2138/rmg.2006.63.16.

18. Repper J., Hofmann M., Krempaszky C., Regener B., Berhuber E., Petry W., Werner E. Effect of macroscopic relaxation on residual stress analysis by diffraction methods. Journal of Applied Physics, 2012, vol. 112, p. 64906. DOI: 10.1063/1.4752877.

19. Fujita F.E. A statistical thermodynamic theory of pre-martensitic tweed structure. Materials Science and Engineering: A, 1990, vol. 127, pp. 243–248. DOI: 10.1016/0921-5093(90)90315-T.

20. Londoño-Restrepo S.M., Herrera-Lara M., Bernal-Alvarez L.R., Rivera-Muñoz E.M., Rodriguez-García M.E. In situ XRD study of the crystal size transition of hydroxyapatite from swine bone. Ceramics International, 2020, vol. 46, pp. 24454–24461. DOI: 10.1016/j.ceramint.2020.06.230.

21. Youssef L., Kinfack Leoga A.J., Roualdes S., Bassil J., Zakhour M., Rouessac V., Ayral A., Nakhl M. Optimization of N-doped TiO₂ multifunctional thin layers by low frequency PECVD process. Journal of the European Ceramic Society, 2017, vol. 37, pp. 5289–5303. DOI: 10.1016/j.jeurceramsoc.2017.05.010.

22. Daniel R., Holec D., Bartosik M., Keckes J., Mitterer C. Size effect of thermal expansion and thermal/intrinsic stresses in nanostructured thin films: Experiment and model. Acta Materialia, 2011, vol. 59, pp. 6631–6645. DOI: 10.1016/j.actamat.2011.07.018.

23. Manjunath N., Santhy K., Rajasekaran B. The effect of strain induced phase transformation on the thermal expansion compatibility of plasma sprayed spinel coating on SOFC metallic interconnect – A study using in situ high temperature X-ray diffraction. International Journal of Hydrogen Energy, 2023, vol. 48 (81), pp. 31767–31768. – DOI: 10.1016/j.ijhydene.2023.04.322.