Spatially resolved X-Ray analysis of machining induced white layers
| Reference number | |
| Coordinator | Lunds universitet - Institutionen för maskinteknologi - Lunds universitet |
| Funding from Vinnova | SEK 392 000 |
| Project duration | November 2020 - April 2022 |
| Status | Completed |
| Venture | Research infrastructure - utilisation and collaboration |
| Call | Industrial pilot projects for utilisation of large-scale infrastructures for neutron and photon based techniques – 2020 |
| End-of-project report | 2020-03784__SecoTools.pdf (pdf, 408 kB) |
Important results from the project
The overall goal is to give Seco Tools AB the opportunity to access a large-scale research infrastructure (eg MaxIV) to perform advanced material characterization and assess the effect of cutting tool material design on the surface integrity of machined metallic alloys. With special focus on identifying the impact of tool wear on the microstructure changes during the formation of a so-called machining-induced white layer (WL). We have successfully achieved this objective because as we were able to perform X-ray diffraction (nano-XRD) of the WL at two synchrotron beam lines.
Expected long term effects
The results obtained in this study give us a better understanding of some characteristic features of machining induced WL. The analysis of individual grains of WL with Bragg Coherent Diffraction Imaging (BCDI) suggests that it is possible to use this method for reconstruction of individual grains and map their elastic elongation. Replicating such measurement over multiple grains would allow us in the future to obtain relevant information about local strain gradients in the WL.
Approach and implementation
FIB Lamella specimens of about 1 micrometer thickness were extracted from machined IN718 samples. Synchrotron diffraction experiments were performed at both the P10 beam (Petra III - Hamburg) and the NanoMAX beam (MAX IV - Lund). Both beam lines have similar capabilities and the latter offers a much better resolution for Nano-XRD and XRF analysis. The thin lamella were studied in transmission geometry and the strain distribution was examined by tracking (111) Bragg reflection of the -phase while the sample was scanned with the beam.