Investigation of some Intrinsic Properties of Thermal Sprayed Molybdenum Coatings for Railway Axle Applications

Abstract:

Thermal sprayed Mo coatings deposited on steel support deposited by electric arc and atmospheric plasma spray were investigated. Microstructural investigation of the coatings showed that in both variants the splats formed by rapid solidification and splashing during the impact with the substrate have irregular shape, exhibit cracks and scattered debris. The measured average equivalent diameter of the splats and the calculated average diameter of the particles that generated the splats are higher for electric arc spraying. Using the measured and calculated data it was descibed the relathionship between splats diameter, splats thickness and flattening degree. Some intrinsec properties of the coatings as roughness, hardness and bond strength were measured. All these properties are influenced by the splat size. Lower size of the splats lead to reduced surface roughness, higher hardness and higher bond strength of the coatings.

• Periodical: Applied Mechanics and Materials (Volume 811)
• Pages: 19-23
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.811.19
• Online since: November 2015
• Authors: Gheorghe Matache*, Cristian Puscasu, Alexandru Paraschiv, Oana Trusca
• Keywords: Flattening Degree, Molybdenum, Railway Axle, Thermal Spray

References

[1] A. Smith, Fatigue of railway axles: a classic problem revisited, Proceeding of 13th European Conference on Fracture, (2000) 173-181.

DOI: 10.1016/s1566-1369(00)80049-7

[2] C. Bathias, K.J. Miller, S. Stanz-Tschegg, Special issue on gigacycle fatigue, Fatigue & Fracture of Engineering Materials & Structures, 22(7) (1999) 601-607.

DOI: 10.1046/j.1460-2695.1999.00206.x

[3] U. Zerbst, M. Vormvald, C. Andersch, C. et al., The development of a damage tolerance concept for railway components and its demonstration for a railway axle, Eng. Fract. Mech., 72 (2005) 209-239.

DOI: 10.1016/j.engfracmech.2003.11.011

[4] S. Beretta, M. Carboni, Experiments and stochastic model for propagation lifetime of railway axles, Eng. Fract. Mech. 73 (2006) 2627–2641.

DOI: 10.1016/j.engfracmech.2006.04.024

[5] S. Beretta, M. Madia, M. Schoedel, U. Zerbst, SIF solutions for cracks at notches under rotating bending, Proc. 16th European conference on fracture, Alexandropolis, Greece, (2006).

DOI: 10.1007/1-4020-4972-2_129

[6] S.J. Harris, M.P. Overs, A.J. Gould, The use of coatings to control fretting wear at ambient and elevated temperatures, Wear 106 (1985) 33- 52.

DOI: 10.1016/0043-1648(85)90102-4

[7] Y. Fu, J. Wei, A.W. Batchelor, Some considerations on the mitigation of fretting damage by the application of surface-modification technologies, J. Mater. Process. Techn. 99 (2000) 231 – 245.

DOI: 10.1016/s0924-0136(99)00429-x

[8] S. Sampath, S.F. Wayne, Microstructure and Properties of Plasma-Sprayed Mo-Mo2C Composites, Joumal of Thermal Spray Technology, 282, Volume 3(3) September (1994).

DOI: 10.1007/bf02646273

[9] D. Shi, M. Li and P.D. Cristofides, Diamond Jet Hybrid HVOF Thermal Spray: Rule Based Modeling of Coating Microstructure, Ind. Eng. Chem. Res. 2004, 43, 3653-3665.

DOI: 10.1021/ie030560h

[10] J. Matejicek, S. Sampath, J. Dubsky, X-ray Residual Stress Measurement in Metallic and Ceramic Plasma Sprayed Coatings, J. Therm. Spray Techn. 7(4) (1998) 489-496.

DOI: 10.1361/105996398770350701

[11] S. Sampath and X. Jiang, Splat formation and microstructure development during plasma spraying: deposition temperature effects, Mat. Sci. Eng. A 304-306 (2001) 144-150.

DOI: 10.1016/s0921-5093(00)01464-7