Intermethod Comparison and Evaluation of Measured Near Surface Residual Stress in Milled Aluminum

Abstract Background While near surface residual stress (NSRS) from milling is a driver for distortion in aluminum parts there are few studies that directly compare available techniques NSRS measurement. Objective We report application and assessment of four different evaluating versus depth milled parts. Methods The are: hole-drilling, slotting, cos(?) x-ray diffraction (XRD), sin 2 (?) XRD, all including incremental material removal to produce profile. cut stress-relieved plate, AA7050-T7451, with range table tool speeds used mill large flat several samples. measurements made at specified locations on each sample. Results Resulting data show three general agreement: XRD. At shallow depths (< 0.03 mm), XRD have the best repeatability 15 MPa), but larger (> 0.04 mm) hole-drilling slotting 10 MPa). differ provided by other less repeatable. parameters increases feed per tooth unaffected cutting speed. Conclusion Hole-drilling, comparable results when assessing milling-induced aluminum. Combining simple test, comprising 1 mm thick wafer surface, companion analysis showed most consistent distortion.