Effect of post weld heat treatment of inconel 718 alloy on mechanical properties
Toe, Thu Yein
Date of Issue2017-05-30
School of Mechanical and Aerospace Engineering
In this study, only two mechanical properties, hardness and fatigue, were considered. Most of the aerospace components requirement high impact toughness, high corrosion resistance and good fracture toughness. Considering other important mechanical properties to determine an optimum PHWT temperature will make the analysis more realistic. SEM machine can be used to analyses different phases more accurately and grain boundaries that could not be seemed by normal optical microscope’s magnification. On top of this, Energy Dispersive X-Ray (EDX) can be utilized to measure the niobium contents at different PWHTs. It is necessary because niobium contents at different PWHTs for particular phase is always changing and these changes are not possible to detect by just analyzing microstructure, size of grain boundaries and type of phases. Computer simulation can be done for 3-points bending tests to obtain the optimum results and comparison can be made with the experimental results. Measurement of residual stresses in both longitudinal and lateral direction after welding and after PWHTs is necessary. Relationship between residual stresses and mechanical properties such as hardness and fatigue can be further developed to make repair process more efficient and effective.
Final Year Project (FYP)
Nanyang Technological University