The effect of Machining and Subsurface Microstructure on the Fatigue Performance of Ti-6246Thursday (07.11.2019) 11:45 - 12:05 Part of:
This study is centred in understanding how microstructural and machining induced features in Ti-6246 affect fatigue life. In order to evaluate this, one of the techniques that can used to assess the fatigue performance of a material is the 4-point bend test. Such a testing approach is inexpensive, enables assessment of a range of machining parameters and the ability to assess a range of locations on a part.
Test pieces will be obtained from rectilinear forgings via EDM, which is the pre-machined state of the compressor disc. The fatigue life of the different coupons will be compared, as a function of the different surface conditions, machining parameters and the position from where they were extracted in the forging (FIG 1.). The pattern produced by the fatigue life plot resembles the strain pattern (FIG 2.) induced during the forging steps of the component.
The main interests of this study will be to determine the role of upstream forging induced texture and downstream surface modification and sub-surface severe plastic deformation induced through machining, on fatigue life.
The data gathered during this research will be used to design new machining processes focused in increasing the material removal rate (and hence productivity), while maintaining or enhancing the quality and fatigue life of the component.