All Outputs (120)

On tilt and curvature dependent errors and the calibration of coherence scanning interferometry (2017)
Journal Article

Although coherence scanning interferometry (CSI) is capable of measuring surface topography with sub-nanometre precision, it is well known that the performance of measuring instruments depends strongly on the local tilt and curvature of the sample su... Read More about On tilt and curvature dependent errors and the calibration of coherence scanning interferometry.

Combined inkjet printing and infrared sintering of silver nanoparticles using a swathe-by-swathe and layer-by-layer approach for 3-dimensional structures (2017)
Journal Article

Despite the advancement of additive manufacturing (AM)/3-dimensional (3D) printing, single-step fabrication of multifunctional parts using AM is limited. With the view of enabling multifunctional AM (MFAM), in this study, sintering of metal nanoparti... Read More about Combined inkjet printing and infrared sintering of silver nanoparticles using a swathe-by-swathe and layer-by-layer approach for 3-dimensional structures.

Aerial wetting contact angle measurement using confocal microscopy (2016)
Journal Article

A method is presented in which the wetting contact angle of a sessile drop is acquired aerially using confocal techniques to measure the radius and the height of a droplet deposited on a planar surface. The repeatability of this method is typically l... Read More about Aerial wetting contact angle measurement using confocal microscopy.

Assessing the capability of in-situ nondestructive analysis during layer based additive manufacture (2016)
Journal Article

Unlike more established subtractive or constant volume manufacturing technologies, additive manufacturing methods suffer from a lack of in-situ monitoring methodologies which can provide informationrelating to process performance and the formation of... Read More about Assessing the capability of in-situ nondestructive analysis during layer based additive manufacture.

Shape descriptors and statistical classification on areal topography data for tile inspection in tessellated surfaces (2016)
Journal Article

Verification of conformance to design specifications in production, and identification of defects related to wear or other damage during maintenance, are key metrological aspects that must be addressed for micro-scale tessellated surfaces. A new algo... Read More about Shape descriptors and statistical classification on areal topography data for tile inspection in tessellated surfaces.

Study of weighted fusion methods for the measurement of surface geometry (2016)
Journal Article

© 2016 Elsevier Inc. Four types of weighted fusion methods, including pixel-level, least-squares, parametrical and non-parametrical, have been classified and theoretically analysed in this study. In particular, the uncertainty propagation of the weig... Read More about Study of weighted fusion methods for the measurement of surface geometry.

Quadrature wavelength scanning interferometry (2016)
Journal Article

A novel method to double the measurement range of wavelength scanning interferometry (WSI) is described. In WSI the measured optical path difference (OPD) is affected by a sign ambiguity, i.e. from an interference signal it is not possible to disting... Read More about Quadrature wavelength scanning interferometry.

Loose powder detection and surface characterization in selective laser sintering via optical coherence tomography (2016)
Journal Article

Defects produced during selective laser sintering (SLS) are difficult to non-destructively detect after build completion without the use of X-ray-based methods. Overcoming this issue by assessing integrity on a layer-by-layer basis has become an area... Read More about Loose powder detection and surface characterization in selective laser sintering via optical coherence tomography.

Metrology for additive manufacturing (2016)
Journal Article

Phase and fringe order determination in wavelength scanning interferometry (2016)
Journal Article

A method to obtain unambiguous surface height measurements using wavelength scanning interferometry with an improved repeatability, comparable to that obtainable using phase shifting interferometry, is reported. Rather than determining the conventio... Read More about Phase and fringe order determination in wavelength scanning interferometry.

Performance assessment of a new variable stiffness probing system for micro-CMMs (2016)
Journal Article

When designing micro-scale tactile probes, a design trade-off must be made between the stiffness and flexibility of the probing element. The probe must be flexible enough to ensure sensitive parts are not damaged during contact, but it must be stiff... Read More about Performance assessment of a new variable stiffness probing system for micro-CMMs.

Review of post-process optical form metrology for industrial-grade metal additive manufactured parts (2016)
Journal Article

The scope of this review is to investigate the main post-process optical form measurement technologies available in industry today and to determine whether they are applicable to industrial-grade metal additive manufactured parts. An in-depth review... Read More about Review of post-process optical form metrology for industrial-grade metal additive manufactured parts.

Review of in-situ process monitoring and in-situ metrology for metal additive manufacturing (2016)
Journal Article

Lack of assurance of quality with additively manufactured (AM) parts is a key technological barrier that prevents manufacturers from adopting AM technologies, especially for high-value applications where component failure cannot be tolerated. Develop... Read More about Review of in-situ process monitoring and in-situ metrology for metal additive manufacturing.

Study of manufacturing and measurement reproducibility on a laser textured structured surface (2016)
Journal Article

In recent years there has been increasing interest in the use of structured surfaces to provide specific functional performance. Such surfaces often consist of localised micro-scale surface features with predetermined geometries. The performance of t... Read More about Study of manufacturing and measurement reproducibility on a laser textured structured surface.

An international comparison of surface texture parameters quantification on polymer artefacts using optical instruments (2016)
Journal Article

An international comparison of optical instruments measuring polymer surfaces with arithmetic mean height values in the sub-micrometre range has been carried out. The comparison involved sixteen optical surface texture instruments (focus variation in... Read More about An international comparison of surface texture parameters quantification on polymer artefacts using optical instruments.

Quantification and characterisation of porosity in selectively laser melted Al–Si10–Mg using x-ray computed tomography (2016)
Journal Article

We used X-ray computed tomography (CT), microscopy and hardness measurements to study Al–Si10–Mg produced by selective laser melting (SLM). Specimens were subject to a series of heat treatments including annealing and precipitation hardening. The spe... Read More about Quantification and characterisation of porosity in selectively laser melted Al–Si10–Mg using x-ray computed tomography.

Model-based defect detection on structured surfaces having optically unresolved features (2015)
Journal Article

In this paper, we demonstrate, both numerically and experimentally, a method for the detection of defects on structured surfaces having optically unresolved features. The method makes use of synthetic reference data generated by an observational mode... Read More about Model-based defect detection on structured surfaces having optically unresolved features.

Texture-based segmentation with Gabor filters, wavelet and pyramid decompositions forextracting individual surface features from areal surface topography maps (2015)
Journal Article

Surface texture measurement for additive manufacturing (2015)
Journal Article

The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder's particle size distribution, the effect of the heat source, the thickness of the printed layers, the... Read More about Surface texture measurement for additive manufacturing.

Laser ultrasound measurement of diaphragm thickness, Young’s modulus and Poisson’s ratio in a MEMS device
Journal Article

Laser-generated Lamb waves, coupled with a large bandwidth Michelson interferometer, have been demonstrated to accurately measure the thickness of a MEMS pressure sensor diaphragm in the [110] direction of a silicon wafer. Using the reassigned Gabor... Read More about Laser ultrasound measurement of diaphragm thickness, Young’s modulus and Poisson’s ratio in a MEMS device.