Effect of SMAT Parameters on Microstructural Features using DOE Technique

Author:  Chemkhi, Retraint, Montay, Garnier, Belahcene
Source:  Conf Proc 2011: ICSP-11 South Bend, IN USA (pgs. 87-92)
Doc ID:  2011014
Year of Publication:  2011
Abstract:  
Abstract SMAT (Surface Mechanical Attrition Treatment) is a beneficial method to improve the fatigue properties of components and structures. This treatment generates surface nanocrystallization as well as strain hardening provided by severe plastic deformation via multidirectional and random shot impacts. Residual stresses, surface roughness, nanocrystalline layer and work hardening are the main surface effects induced by SMAT. They are closely dependant on the choice of the SMAT parameters. In this paper Design Of Experiment (DOE) technique was used to examine the effect of process parameters such as sonotrode amplitude and processing time on microstructural features of 316L ASTM F138 alloy. The sonotrode amplitude was revealed to be the most influencing SMAT parameter while interaction between factors could not be neglected. Mathematical models linking the process parameters to the surface properties were developed. The choice of the influencing parameters could thus be optimized according to the roughness and/or the micro-hardness evolution. Keywords: SMAT, nanocrystallization, DOE, roughness, micro-hardness, residual stress