Additive manufacturing (AM) has the capability to build complex parts with internal features, which have many advantages over conventionally manufactured parts. This makes AM an alternative for advanced sectors. components suffer from defects due lack of understanding in process. adaptation safety-critical industries, such as aerospace, problematic. The current work flow calls costly off-line inspections qualify defect-free. layer by nature provides opportunity on-line inspection take place....

In this work we employ additive manufacturing to print a circular array of micropillars on an aluminium slab turning its top surface into graded index metasurface for acoustic waves (SAW). The reproduces Luneburg lens capable focusing plane SAWs point. profile is obtained by exploiting the dispersion properties arising from well-known resonant coupling between (0.5 mm diameter and variable length ∼3 mm) propagating in substrate. From analytical formulation metasurface's curves, slow phase...

Additive manufacturing (AM) is a production technology where material accumulated to create structure, often through added shaped layers. The major advantage of additive in creating unique and complex parts for use areas conventional reaches its limitations. However, the current class AM systems produce that contain structural defects (e.g., cracks pores) which not compatible with certification high value industries. probable complexity an design increases difficulty using many...

Orientation affects application-defining properties of crystalline materials. Hence, information in this regard is highly-prized. We show that electrochemical jet processing (EJP), when coupled with accurate metrological appraisal, can characterise crystallographic texture. Implementation technique allows localised dissolution to be anisotropic and dependent on etch-rate selectivity, defined by the crystallography. EJP therefore, generates complex, but characteristic topographies. Through...

Elastic waves guided along surfaces dominate applications in geophysics, ultrasonic inspection, mechanical vibration, and surface acoustic wave devices; precise manipulation of Rayleigh their coupling with polarized body presents a challenge that offers to unlock the flexibility transport required for efficient energy harvesting vibration mitigation devices. We design elastic metasurfaces, consisting graded array rod resonators attached an substrate that, together critical insight from...

Detection of machining-induced white layers is currently a destructive inspection process with form cross-sectional microscopy required. This paper, therefore, reports on the development novel non-destructive method for detecting using grain size-sensitive and crystallographic texture-sensitive techniques. It shown that x-ray diffraction can be used to detect as thin 5 μm in Ti-6Al-4 V through measurement peak breadths intensities, due influence sub 100 nm size high lattice strain layer,...

The microstructure of a material defines many its mechanical properties. Tracking the parts during their manufacturing is needed to ensure designed performance can be obtained, especially for additively manufactured parts. Measuring non-destructively on real challenging optical techniques such as laser ultrasound, optically rough surface impacts ability generate and detect acoustic waves. Spatially resolved spectroscopy used measure microstructure, this paper presents capability range...

In-process inspection of the additive manufacturing process requires a technique that can provide reliable measurements given extreme operating environments, small size defects and cyclic melting heating material, caused by subsequently deposited layers. A remote couplant-free ultrasonic using bulk waves image near-surface could address these in-process requirements. Laser induced phased arrays (LIPA) generate detect ultrasound based on laser ultrasonics principles, while array is...

Wire–arc additive manufacturing (WAAM) is an emergent method for the production and repair of high value components. Introduction plastic strain by inter-pass rolling has been shown to produce grain refinement improve mechanical properties, however suitable quality control techniques are required demonstrate non-destructively. This work proposes a rapid microstructural assessment Ti–6Al–4V, with limited intervention, measuring acoustic wave generated on surface specimens. Specifically,...

Spatially resolved acoustic spectroscopy towards online inspection of additive manufacturingHigh-integrity engineering applications such as aerospace will not permit the incorporation components containing any structural defects.The current generation manufacturing (AM) platforms yield with relatively high levels in-line built using AM can provide closed-loop feedback and vary build parameters during fabrication to minimise defects.This article reviews capability spatially (SRAS) be used an...

There is a clear industrial pull to fabricate high value components using premium temperature aerospace materials by additive manufacturing. Inconveniently, the same material properties which allow them perform well in service render difficult process via powder bed fusion. Current build systems are charac-terised defect rates and erratic microstructure, leading with inferior mechanical properties. The work presents microstructural texture imaging of powder-bed fusion non-contact laser...

Laser Induced Phased Array (LIPA) is a non-contact, couplant-free inspection technique providing high quality ultrasonic imaging. LIPAs use lasers for ultrasound generation and detection: beam forming performed in post processing, using delay-and-sum algorithms, while the data acquisition done by scanning two lasers, offering unique flexibility array designs that are currently impossible to achieve with conventional transducer based phased arrays. When synthesizing 2D LIPA, 3D imaging can be...

Spatially resolved acoustic spectroscopy (SRAS) is an microscopy technique that can image the microstructure and measure crystallographic orientation of grains or crystals in material.It works by measuring velocity surface waves (SAWs) via spectrum. In usual configuration, SAWs are generated laser using a pattern lines detected at point close to this grating-like source. The use spectrum as means has number practical advantages which makes robust fast gives good spatial resolution. This...

Abstract Three-dimensional (3D) ultrasonic imaging enables the viewing of internal features in a more accurate way than cross-sectional imaging. 3D requires two-dimensional (2D) phased arrays to resolve all three spatial dimensions through beamforming along azimuthal and elevation angles. 2D pose manufacturing control challenge due requirement large number elements satisfy Nyquist sampling limit. This problem can be alleviated use sparse array designs. The optimization process is critical,...

Laser Induced Phased Arrays (LIPAs) use lasers to generate and detect ultrasound, synthesizing the array in post processing. Data acquisition is done remotely, without couplant, addressing NDE challenges of inspection on complex structures under extreme environments. Previously high-resolution ultrasonic imaging components using LIPAs have been demonstrated by capturing Full Matrix employing Total Focusing Method (TFM) as algorithm. However, Capture data method requires long time due...

Laser Induced Phased Arrays (LIPAs) are based on the principles of laser ultrasonics where ultrasound is generated and detected by lasers. The beams scanned inspected component, collecting data from various array element positions. In this way, an synthesized in post processing applying a variety ultrasonic imaging algorithms. Unlike transducer phased arrays, which have fixed geometry instrumentation, number elements pitch as well operational frequency, LIPAs present flexibility design...

The recently proposed selective matrix capture approach used in inspections with laser induced phased-arrays has made this technology faster and more accurate. process consists of two stages, one for rapid defect detection another high fidelity characterisation. phased-array configuration is optimally adapted to the current inspection scenario each stage. This paper proposes a rigorous optimisation stage case large component where array scanned along length component. requires an that...

In-process inspection of the additive manufacturing process requires a technique that can provide reliable measurements given extreme operating environments, small size defects and cyclic melting heating material, caused by subsequently deposited layers. A remote couplant-free ultrasonic using bulk waves image near-surface could address these in-process requirements. Laser induced phased arrays (LIPA) generate detect ultrasound based on laser ultrasonics principles, while array is...

Abstract Laser induced phased arrays (LIPAs) offer fast and efficient remote ultrasonic imaging for processes operating in extreme environments restricted access such as additive manufacturing welding. In this work, LIPAs are synthesized the non-destructive thermoelastic regime using an 8 ns pulsed 1064 nm generation laser a 532 continuous wave detection laser. The acquired Full Matrix data is post-processed Total Focusing Method (TFM) to image near-surface side-drilled holes inside...