An EU-funded research project, Intrapid, has developed a series of systems for rapid in-line inspection of laser powder deposited layers. The work, using specially designed non-destructive testing techniques, has important implications for the aerospace and automotive sectors, for example, where validation of components made using additive manufacturing techniques has until now been difficult to achieve.
The team chose to use laser ultrasonics, laser thermography and eddy current testing techniques in its system designs because each of these has a small inspection footprint – necessary to inspect a thin deposited layer. The systems comprised newly built specialist equipment together with a software suite, which included the data acquisition, display and analysis.
To determine inspection performance, the researchers produced a wide range of reference samples in different materials and of varied shape containing machined flaws. They also devised techniques to introduce known flaws in deposited layers of either Inconel 600 or a copper alloy on aluminium substrate. Subsequent testing of these samples enabled the team to produce performance data for each inspection method, as a graph comparing flaw size against its depth below surface.
One of the systems is expected to be used first by the automotive industry in the production of a new generation of laser-additive-manufactured components.
Intrapid was co-ordinated in the UK by TWI, with project partners Bytest (Italy), Tecnitest (Spain), Polkom (Poland), LPW Technology (UK), Toyota (Belgium), Kingston Computer Consultancy (UK), UNIPA (Italy). The work was funded by the EC through the Research Executive Agency.