title: Inspection of additive-manufactured layered components.
abstract: Laser powder deposition (LPD) is a rapid additive manufacturing process to produce, layer upon layer, 3D geometries or to repair high-value components. Currently there is no nondestructive technique that can guarantee absence of flaws in LPD products during manufacturing. In this paper a laser ultrasonic technique for in-line inspection of LPD components is proposed. Reference samples were manufactured from Inconel and machined flaws were created to establish the sensitivity of the technique. Numerical models of laser-generated ultrasonic waves have been created to gain a deeper understanding of physics, to optimize the set-up and to verify the experimental measurements. Results obtained on two sets of reference samples are shown. A proof-of-concept prototype has been demonstrated on some specific deposition samples with induced flaws, that were confirmed by an ultra-high sensitivity X-ray technique. Experimental outcomes prove that typical micro-defects due to the layer-by-layer deposition process, such as near-surface and surface flaws in a single layer deposit, can be detected.
authors.affiliation: Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica (DICGIM), Università di Palermo, viale delle Scienze, 90128 Palermo, Italy. Electronic address: donatella.cerniglia@unipa.it.
authors.forename: D
authors.initials: D
authors.lastname: Cerniglia
authors.affiliation: Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica (DICGIM), Università di Palermo, viale delle Scienze, 90128 Palermo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Scafidi
authors.affiliation: Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica (DICGIM), Università di Palermo, viale delle Scienze, 90128 Palermo, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Pantano
authors.affiliation: TWI Ltd., Granta Park, Abington, Cambridge CB21 6AL, UK.
authors.forename: J
authors.initials: J
authors.lastname: Rudlin
keywords: Additive manufacturing; FEM; Laser powder deposition; Laser ultrasound; NDT inspection