PSI - Issue 14

R.K. Kumar et al. / Procedia Structural Integrity 14 (2019) 134–141

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S. Anand Kumar / Structural Integrity Procedia 00 (2018) 000–000

depth of 50 μm. However for increased pressure conditions, the zero stress state is reached after the depth of about 80 μm from the surface. For components subjected to cyclic loading condition, the increased stress gradient generally appears beneficial in terms of improved service life. 4. Conclusions The following conclusions emerge from this investigation. Optimization of coverage area, Almen intensity, surface roughness and residual stress processes have been achieved for improved fatigue life of shot peened Ti-6Al-4V alloy. It is observed from the design experiments involving ANOVA, that the fisher’s ratio calculated is very useful to optimize the parameters viz., exposure time and peeing pressure etc. It is seen that the coverage area is directly proportional to the time of exposure and follows a linear trend. The surface roughness increases with increase in increase in peening pressure inducing plastic deformation. Compressive residual stresses in the vicinity of 765 MPa on the surface and about 825 MPa and 870 MPa at a depth of 25 and 40 microns, respectively have been achieved by the shot peening process, which have bearing on the fatigue life. The curve fits based on the regression equations obtained in respect of coverage area, Almen intensity, induce of surface roughness and residual stresses at the surface due to shot peening process have been generated, which may serve as calibration curves for this class of material. Acknowledgements The authors wish to acknowledge with thanks for the support and encouragement given by the managements of CPRI, NDRF, IIT-Jammu, TERI and SaIT to present and publish this paper. References Leyens, Peters, M., 2003. Titanium and Titanium Alloys Fundamentals and Applications. Wiley-Vch, Weinheim. Laneza, V. L., Belzunce F.J., 2015. Optimal Shot Peening Treatments to Maximize the Fatigue Life of Quenched and Tempered Steels. Journal of Materials Engineering and Performance, 24, pp. 2806–2815. Fathallah, R., Sidhom, H., Braham, C., Castex, L., 2003. Effect of Surface Properties on High Cycle Fatigue Behavior of Shot Peened Ductile Steel. Material Science Technology, 19 (8), pp. 1050–1056. Jebahi, M., Gakwaya, A., Leveskue, J., Mechri, O., Ba K., 2016. Robust Methodology to Simulate Real Shot Peening Process Using Discrete Continuum Coupling Method. International Journal of Mechanical Sciences, 107, pp. 21-33. Skowronek, A., 2007. Optimization of Elastic Experiment Plan Generativity. Czasopismo Techniczne, Informatyka, Wydawnictwo Politechniki Krakowskiej, pp. 63-74. Lundstedt, T., Seifert, E., Abramo, L., Thelin, B., Nyström, A., Pettersen, J., Bergman, R., 1998. Experimental Design and Optimization. Chemometrics and Intelligent Laboratory Systems, 42, pp. 3-40. Mahagaonkar, S.B., Brahmankar P.K., Seemikeri C.Y., 2008. Effect of Shot Peening Parameters on Microhardness of AISI 1045 and 316LMaterial: an Analysis Using Design of Experiment. International Journal of Advanced Manufacturing Technology 38, pp. 563–574. Aylott, J., Lassithiotakis, D., 2005. Optimizing Shot Peening Parameters Using DOE. 9 th International Conference on Shot Peening, pp. 406-412. SAE Aerospace, SAE Standard AMS (Aerospace Material Specification), 2012, AMS B Finishing Processes and Fluids Committee, SAE International. Cullity, B.D., 1978. Elements of X-ray Diffraction. Addison-Wesley: Menlo Park, CA. Noyan, I.C., Cohen, J.B., 1987. Residual Stress. Springer-Verlag, New York. Vielma A.T., Llaneza V., Belzunce F.J., 2014. Effect of Coverage and Double Peening Treatments on the Fatigue Life of a Quenched and Tempered Structural Steel. Surface Coating Technology 249, pp 75–83. Wagner, 2009. The Shot Peener, Springer. Roy, R.K., 1990. A Primer on Taguchi Method. Van Noshtrand Reinhold International Cooperation Limited, New York. Dai, K., Villegas, J., Stone, Z., Shaw, L., 2004. Finite Element Modeling of the Surface Roughness of 5052 Al Alloy Subjected to a Surface Severe Plastic Deformation Process. Acta Materialia 52, pp. 5771-5782. Shivpuri, Cheng, X., Mao, Y., 2009. Elasto-Plastic Pseudo-Dynamic Numerical Model for the Design of Shot Peening Process Parameters. Materials & Design 30, pp. 3112–3120.