Production of Ferrous PM-Parts for Calibration and Demonstration of Typical Defect Detection Performance of In-Line X-Ray Digital Radiography Equipment

摘要

Non destructive testing (NDT) of ferrous PM-parts is a very demanding task, due to the various structural features (e.g. porosity, density variations, inhomogeneous microstructures) that are typical for these products, undesired features (cracks, voids) are much harder to detect. Digital radiography opens the possibility to perform testing online within the production process, since the detection is fast enough for the typical output of PM production lines. For calibration of the system, reference PM-parts are needed to investigate and validate the performance of the system. Therefore laboratory parts with different compositions have been produced in a wide range of density and thickness and characterised in green and sintered state for having reference properties for the X-ray investigation. Special samples were created to demonstrate of the detection abilities of the system: e.g. samples with defined holes and cracks, stepped samples with cracks or parts with hidden cracks. Selected results acquired with a new developed X-ray digital radiography system based on TDI (Time Delay Integration) detector will be presented and discussed.