Surface integrity analysis of WEDMed specimen of Inconel 825 superalloy

Abstract: WEDM has evolved as a well admired technique for machining of difficult to cut materials such as superalloys. WEDM produces intricate shape and profiles of superalloys by thermoelectric erosion process. But as the process is carried out at very high temperature, the formation of heat affected zone, microcracks, recast layer, porosity etc. resulted in decreased surface integrity of machined specimen and becomes a big problem in WEDM. Discharge energy is the most influencing param-eters that affect the surface integrity of WEDmed samples. In this study, Inconel 825, widely used in aerospace industry for making of combustor casing and turbine blades, was machined with WEDM under different discharge energy. The surface topography of the WEDMed specimen was carried cut by using SEM, XRD and EDX techniques. It was observed from the SEM micrograph that the machined surface includes cracks, pockmarks, craters, and pulled out material. The density and sice of craters increase with increase in discharge energy. Surface crack density of 0.0138 μm/μm2 and recast layer thickness of 34.62μm was obtained for the machined sample at high value of discharge energy while at low value surface crack density of 0.0016 μm/μm2 and recast layer thickness of 20.99μm was observed. EDX and XRD analysis of the specimen showed that an ap-preciable amount of elements viz. Fe (Ferrous), Cr (Chromium), Cu (Copper), Ni (Nickel) are mi-grated to the surface of the workpiece at high value of pulse on time.

How to cite this paper

 Kumar, P., Gupta, M & Kumar, V. (2018). Surface integrity analysis of WEDMed specimen of Inconel 825 superalloy.International Journal of Data and Network Science, 2(3), 79-88.

Refrences

Aggarwal, V., Singh, S., & Garg, R.K. (2015) Parametric modeling and optimization for wire electrical discharge machining of Inconel 718 using response surface methodology. International Journal of Advanced Manufacturing Technology, 79, 31-47.
Aspinwall, D.K., Soo, S.L., Berrisford, A.E., & Walder, G. (2008). Workpiece surface roughness and integrity after WEDM of Ti 6Al 4V and Inconel 718 using minimum damage generator technology. CIRP Annals, 57(1), 187-190.
Çaydas, U., & Ay, M. (2016). WEDM cutting of Inconel 718 nickel-based superalloy: effects of cut-ting parameters on the cutting quality. Materials and Technology, 1, 117–125.
Chen, Z., Moverare, J., Peng, R.L., & Johansson, S. (2016). Surface Integrity and Fatigue Performance of Inconel 718 in Wire Electrical Discharge Machining. Procedia CIRP, 45, 307-310.
Chuanliang, C., Xianglin, Z., Xiang, Z, & Chunfa, D. (2014). Surface Integrity of Tool Steels Multi-cut by Wire Electrical Discharge Machining. Procedia Engineering, 81, 1945-1951.
Garg, M.P., Kumar, A., & Sahu, C.K. (2017). Mathematical modeling and analysis of WEDM machin-ing parameters of nickel-based super alloy using response surface methodology. Sadhana, 42(6), 981–1005.
Ghodsiyeh, D., Golshan, A., & Shirvanehdeh, J.A. (2013). Review on current research trends in wire electrical discharge machining (WEDM). Indian Journal of Science and Technology, 6, 154-166.
Holmberg, J., Wretland, A., Berglund, J., & Beno, T. (2018). Surface integrity after post processing of EDM processed Inconel 718 shaft. The International Journal of Advanced Manufacturing Technolo-gy, 95(5-8), 2325-2337.
Kanlayasiri, K., & Boonmung, S. (2007). Effects of wire-EDM machining variables on surface rough-ness of newly developed DC 53 die steel: Design of experiments and regression model. Journal of Materials Processing Technology, 192-193, 459-464.
Khan, N. Z., Khan, Z. A., Siddiquee, A.N., & Chanda A.K. (2014). Investigations on the effect of wire EDM process parameters on surface integrity of HSLA: a multi-performance characteristics op-timization. Production and Manufacturing Reserarch, 2(1), 501–518.
Kolli, M., & Kumar, A. (2015) Effect of dielectric fluid with surfactant and graphite powder on Elec-trical Discharge Machining of titanium alloy using Taguchi method. International Journal of Engi-neering Science and Technology, 18, 524-535.
Kumar, A., Kumar, V., & Kumar, J. (2016). Surface crack density and recast layer thickness analysis in WEDM process through response surface methodology. Machining Science and Technology, 20, 201-230.
Kumar, P., Meenu, & Kumar, V. (2018). Optimization of process parameters for WEDM of Inconel 825 using grey relational analysis. Decision Science Letters, 7(4), 405-416.
Li, L., Guo, Y.B., Wei, X.T., & Li, W. (2013). Surface integrity characteristics in wire-EDM of inconel 718 at different discharge energy. Procedia CIRP, 6, 220-225.
Lodhi, B. K., & Agarwal, S. (2014). Optimization of Machining Parameters in WEDM of AISI D3 Steel Using Taguchi Technique. Procedia CIRP, 14, 194 – 199.
Neves, M.D., Lotto, A., Berretta, J.R., de Rossi, W., & Junior, N.D. (2010). Microstructure develop-ment in Nd:YAG laser welding of AISI 304 and Inconel 600. Welding International, 24, 739-748.
Nourbakhsh, F., Rajurkar, K.P., Malshe, A.P., & Cao. J. (2013). Wire Electro-Discharge Machining of Titanium Alloy. Procedia CIRP, 5, 13-18.
Rajyalakshmi, G., & Venkata Ramaiah, P. (2013). Multiple process parameter optimization of wire elec-trical discharge machining on Inconel 825 using Taguchi grey relational analysis. International Jour-nal of Advanced Manufacturing Technology, 69, 1249-1262.
Shen, Y., Liu, Y., Dong, H., Zhang, K., Lv, L., Zhang, X., Wu, X., Zheng, C., & Ji, R. (2017). Surface integrity of Inconel 718 in high-speed electrical discharge machining milling using air dielectric. In-ternational Journal of Advanced Manufacturing Technology, 90, 691-698.
Singh, A., Anandita, S., & Gangopadhyay, S. (2015). Microstructural analysis and multi response opti-mization during ECM of Inconel 825 using hybrid approach. Materials and Manufacturing Processes, 30, 842-851.
Talla, G., Gangopadhyay, S., & Biswas, C. K. (2018). Effect of impregnated powder materials on sur-face integrity aspects of Inconel 625 during electrical discharge machining. Proceedings of the Insti-tution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 232(7), 1259-1272.
Thakur, A., Mohanty, A., Gangopadhyay, S., & Maity, K.P. (2014). Tool wear and chip characteristics during dry turning of Inconel 825. Procedia Material Science, 5, 2169-2177.
Thellaputta, G. R., Pulcharu, S. C., & Rao, C.S.P. (2017). Machinability of Nickel Based Superalloys: A Review. Materials Today: Proceedings, 4(2), 3712-3721.
Tosun, N., & Pihtili, H. (2003). The effect of cutting parameters on wire crater sizes in wire EDM. In-ternational Journal of Advanced Manufacturing Technology, 21, 857-865.