All Outputs (41)

Laser cladding: A high-speed-imaging examination of powder catchment efficiency as a function of the melt pool geometry and its position under the powder stream (2023)
Journal Article
Koti, D., Powell, J., Naesstroem, H., Spaccapaniccia, C., & Voisey, K. T. (2023). Laser cladding: A high-speed-imaging examination of powder catchment efficiency as a function of the melt pool geometry and its position under the powder stream. Journal of Laser Applications, 35(4), Article 042065. https://doi.org/10.2351/7.0001199

This paper provides quantitative information about the paths taken by blown powder particles during laser cladding. A proportion of the powder is "wasted" by bouncing off the solid areas surrounding the melt pool. This wastage reduces the productivit... Read More about Laser cladding: A high-speed-imaging examination of powder catchment efficiency as a function of the melt pool geometry and its position under the powder stream.

Lifetime of MoS2 based DFL systems in fretting with and without a Cu-Ni-In under-layer: the dependence on the topography of the surface onto which the DFL is deposited (2023)
Journal Article
Laolu-Balogun, E., Owen, S., Booth, T., Pattinson, G., Shipway, P., & Voisey, K. (2023). Lifetime of MoS2 based DFL systems in fretting with and without a Cu-Ni-In under-layer: the dependence on the topography of the surface onto which the DFL is deposited. Tribology International, 188, Article 108863. https://doi.org/10.1016/j.triboint.2023.108863

The superior fretting performance of polymer-bonded MoS2-based dry film lubricant (DFL) coating on a plasma-sprayed Cu-Ni-In under-layer is well known. The Cu-Ni-In under-layer changes both the material and the topography of the sur... Read More about Lifetime of MoS2 based DFL systems in fretting with and without a Cu-Ni-In under-layer: the dependence on the topography of the surface onto which the DFL is deposited.

Powder catchment efficiency in laser cladding (directed energy deposition). An investigation into standard laser cladding and the ABA cladding technique (2023)
Journal Article
Koti, D., Powell, J., Naesstroem, H., & Voisey, K. T. (2023). Powder catchment efficiency in laser cladding (directed energy deposition). An investigation into standard laser cladding and the ABA cladding technique. Journal of Laser Applications, 35, Article 012025. https://doi.org/10.2351/7.0000904

This paper investigates the efficiency of powder catchment in blown powder laser cladding (a directed energy deposition technique). A comparison is made between standard “track by overlapping track” cladding (“AAA” cladding) and “ABA” cladding, where... Read More about Powder catchment efficiency in laser cladding (directed energy deposition). An investigation into standard laser cladding and the ABA cladding technique.

Assessing the quality and productivity of laser cladding and direct energy deposition: Guidelines for researchers (2023)
Journal Article
Powell, J., Koti, D., Garmendia, X., & Voisey, K. T. (2023). Assessing the quality and productivity of laser cladding and direct energy deposition: Guidelines for researchers. Journal of Laser Applications, 35(1), Article 012024. https://doi.org/10.2351/7.0000897

This paper provides guidelines and advice to researchers and engineers in the field of laser cladding and related direct energy deposition techniques to help establish a standardized approach to quality assessment and productivity metrics. Factors co... Read More about Assessing the quality and productivity of laser cladding and direct energy deposition: Guidelines for researchers.

Improving laser cladding productivity with ‘ABA’ cladding (2022)
Journal Article
Koti, D., Powell, J., & Voisey, K. (2022). Improving laser cladding productivity with ‘ABA’ cladding. Procedia CIRP, 111, 205-209. https://doi.org/10.1016/j.procir.2022.08.048

Laser Cladding is one of several processes within Additive Manufacturing and usually involves the production of a clad surface by adding parallel, overlapping lines of clad material to the surface of a substrate. In this work a new laser cladding tec... Read More about Improving laser cladding productivity with ‘ABA’ cladding.

Laser drilling of micro-holes in single crystal silicon, indium phosphide and indium antimonide using a continuous wave (CW) 1070 nm fibre laser with millisecond pulse widths (2018)
Journal Article
Maclean, J. O., Tangkijcharoenchai, C., Coomber, S., & Voisey, K. T. (2018). Laser drilling of micro-holes in single crystal silicon, indium phosphide and indium antimonide using a continuous wave (CW) 1070 nm fibre laser with millisecond pulse widths. Procedia CIRP, 74, 407-412. https://doi.org/10.1016/j.procir.2018.08.158

The laser micro-drilling of “thru” holes, also known as via holes, in Si, InP and InSb semiconductor wafers was studied using millisecond pulse lengths from an IPG Laser Model YLR-2000 CW multimode 2 kW Ytterbium Fibre Laser and a JK400 (400 W) fibre... Read More about Laser drilling of micro-holes in single crystal silicon, indium phosphide and indium antimonide using a continuous wave (CW) 1070 nm fibre laser with millisecond pulse widths.

Fibre laser cutting: the use of carbon-filled acrylic as a qualitative and quantitative analysis tool (2018)
Journal Article
Atiyah, H., Powell, J., Petring, D., Stoyanov, S., & Voisey, K. (2018). Fibre laser cutting: the use of carbon-filled acrylic as a qualitative and quantitative analysis tool. Journal of Laser Applications, 30(3), Article 032009. https://doi.org/10.2351/1.5045349

The use of carbon filled black acrylic (CFBA) as a quantitative and qualitative analytical tool for fibre laser cutting is investigated. In the qualitative work CFBA targets placed below the laser cutting zone when cutting stainless steel showed a d... Read More about Fibre laser cutting: the use of carbon-filled acrylic as a qualitative and quantitative analysis tool.

The role of a thermally sprayed CuNiIn underlayer in the durability of a dry-film lubricant system in fretting: a phenomenological model (2018)
Journal Article
Barman, K., Shipway, P., Voisey, K., & Pattinson, G. (2018). The role of a thermally sprayed CuNiIn underlayer in the durability of a dry-film lubricant system in fretting: a phenomenological model. Tribology International, 123, https://doi.org/10.1016/j.triboint.2018.03.018

Dry film lubricant coatings (DFL) are employed to reduce friction and damage in highly loaded contacts. Metallic underlayers, e.g. CuNiIn, can be beneficial however, there is no detailed explanation of the mechanism. This work investigates the effect... Read More about The role of a thermally sprayed CuNiIn underlayer in the durability of a dry-film lubricant system in fretting: a phenomenological model.

An investigation into whether the laser drilling capabilities of a 2kW fibre laser can be enhanced using pulse train shaping (2018)
Journal Article
Markcoons, D., & Voisey, K. (2018). An investigation into whether the laser drilling capabilities of a 2kW fibre laser can be enhanced using pulse train shaping. Lasers in Engineering, 39(1-2),

In long, ms, pulsed melt ejected based laser drilling of metals pulse train shaping has previously improved drilling efficiency. This work investigates if pulse train shaping can be exploited in the laser drilling of 0.8-2 mm mild steel with a 1070 n... Read More about An investigation into whether the laser drilling capabilities of a 2kW fibre laser can be enhanced using pulse train shaping.

Laser drilling of microholes in single crystal silicon using continuous wave (CW) 1070 nm fiber lasers with millisecond pulse widths (2018)
Journal Article
Maclean, J. O., Hodson, J., Tangkijcharoenchai, C., Al-Ojaili, S., Rodsavas, S., Coomber, S., & Voisey, K. (2018). Laser drilling of microholes in single crystal silicon using continuous wave (CW) 1070 nm fiber lasers with millisecond pulse widths. Lasers in Engineering, 39(1-2),

The laser microdrilling of via holes in Si semiconductor wafers was studied using 1 ms pulses from an Yb fibre laser with 1070 nm wavelength. Optical microscopy and cross‑sectional analysis were used to quantify hole dimensions, the distribution of r... Read More about Laser drilling of microholes in single crystal silicon using continuous wave (CW) 1070 nm fiber lasers with millisecond pulse widths.

The effect of coating architecture and defects on the corrosion behaviour of a PVD multilayer Inconel 625/Cr coating (2017)
Journal Article
Daure, J., Voisey, K., Shipway, P., & Stewart, D. (2017). The effect of coating architecture and defects on the corrosion behaviour of a PVD multilayer Inconel 625/Cr coating. Surface and Coatings Technology, 324, https://doi.org/10.1016/j.surfcoat.2017.06.009

This paper investigates the effect of substrate surface finish and deposition conditions of PVD multilayer Inconel 625/Cr coatings on their ability to act as a corrosion-barrier. The corrosion-barrier performance of the coatings was characterized by... Read More about The effect of coating architecture and defects on the corrosion behaviour of a PVD multilayer Inconel 625/Cr coating.

Application of high speed filming techniques to the study of rearwards melt ejection in laser drilling (2017)
Journal Article
Jones, C., Hann, D. B., Voisey, K., & Aitken, S. (in press). Application of high speed filming techniques to the study of rearwards melt ejection in laser drilling. Journal of Laser Applications, 29(2), Article 022204. https://doi.org/10.2351/1.4983269

Melt ejection is the dominant material removal mechanism in long, ms, pulse laser drilling of metals, a process with applications such as the drilling of cooling holes in turbine blades. Droplets of molten material are ejected through the entrance ho... Read More about Application of high speed filming techniques to the study of rearwards melt ejection in laser drilling.

Application of ray-tracing to interpreting beam prints from fibre laser cutting (2017)
Journal Article
Alotaibi, M., Atiyah, H., MacKenzie, R., & Voisey, K. (2017). Application of ray-tracing to interpreting beam prints from fibre laser cutting. Lasers in Engineering, 39(1-2),

2D ray-tracing has been used to investigate the influence of inclined cutting front and the cutting edge on the exiting, surplus, laser beam while cutting 6 mm mild steel with a fibre laser, wavelength = 1070 nm. The ray-tracing model, which assumed... Read More about Application of ray-tracing to interpreting beam prints from fibre laser cutting.

Role of oxides and porosity on high temperature oxidation of liquid fuelled HVOF thermal sprayed Ni50Cr coatings (2017)
Journal Article
Song, B., Bai, M., Voisey, K. T., & Hussain, T. (2017). Role of oxides and porosity on high temperature oxidation of liquid fuelled HVOF thermal sprayed Ni50Cr coatings. Journal of Thermal Spray Technology, 26(3), 554-568. https://doi.org/10.1007/s11666-017-0531-z

High chromium content in Ni50Cr thermally sprayed coatings can generate a dense and protective scale at the surface of coating. Thus, the Ni50Cr coating is widely used in high temperature oxidation and corrosion applications. A commercially available... Read More about Role of oxides and porosity on high temperature oxidation of liquid fuelled HVOF thermal sprayed Ni50Cr coatings.

Evolution of damage in MoS2-based dry film lubricants (DFLs) in fretting wear – the effect of DFL thickness and contact geometry (2017)
Journal Article
Barman, K., Shipway, P., Voisey, K., & Pattinson, G. (2017). Evolution of damage in MoS2-based dry film lubricants (DFLs) in fretting wear – the effect of DFL thickness and contact geometry. Progress in Organic Coatings, 105, https://doi.org/10.1016/j.porgcoat.2016.12.022

Dry film lubricant (DFL) coatings are widely used to reduce coefficients of friction and damage in highly loaded contacts. This work investigates the behaviour of a commercially available MoS2-based DFL in a cylinder-on-flat contact geometry with a f... Read More about Evolution of damage in MoS2-based dry film lubricants (DFLs) in fretting wear – the effect of DFL thickness and contact geometry.

Incorporation and evolution of ZrO2 nano-particles in Pt-modified aluminide coating for high temperature applications (2016)
Journal Article
Qian, L., Xu, F., Voisey, K., Nekouie, V., Zhou, Z., Silberschmidt, V. V., & Hou, X. (2017). Incorporation and evolution of ZrO2 nano-particles in Pt-modified aluminide coating for high temperature applications. Surface and Coatings Technology, 311, https://doi.org/10.1016/j.surfcoat.2016.12.106

ZrO2 nano-particles were incorporated into electro-deposited PtAl coatings in an attempt to enhance their performance by exploiting the effect of reactive element oxides. PtAl coatings with and without ZrO2 particles were deposited onto three commerc... Read More about Incorporation and evolution of ZrO2 nano-particles in Pt-modified aluminide coating for high temperature applications.

Gas and liquid-fuelled HVOF spraying of Ni50Cr coating: microstructure and high temperature oxidation (2016)
Journal Article
Song, B., Pala, Z., Voisey, K., & Hussain, T. (in press). Gas and liquid-fuelled HVOF spraying of Ni50Cr coating: microstructure and high temperature oxidation. Surface and Coatings Technology, https://doi.org/10.1016/j.surfcoat.2016.07.046

Ni50Cr thermally sprayed coatings are widely used for high temperature oxidation and corrosion in thermal power plants. In this study, a commercially available gas atomised Ni50Cr powder was sprayed onto a power plant alloy (ASME P92) using both gas... Read More about Gas and liquid-fuelled HVOF spraying of Ni50Cr coating: microstructure and high temperature oxidation.

Modelling and experimental study on ?-phase depletion behaviour of HVOF sprayed free-standing CoNiCrAlY coatings during oxidation (2016)
Journal Article
Chen, H., Jackson, G., Voisey, K., & McCartney, D. (2016). Modelling and experimental study on ?-phase depletion behaviour of HVOF sprayed free-standing CoNiCrAlY coatings during oxidation. Surface and Coatings Technology, 291, 34-42. https://doi.org/10.1016/j.surfcoat.2016.02.008

This paper investigates the β-phase depletion behaviour during oxidation of free-standing CoNiCrA1Y (Co-31.7%Ni-20.8%Cr-8.1%A1-0.5%Y, all in wt%) bond coats prepared by high velocity oxy-fuel (HVOF) thermal spraying. The microstructure of the coating... Read More about Modelling and experimental study on ?-phase depletion behaviour of HVOF sprayed free-standing CoNiCrAlY coatings during oxidation.

Effects of pre-cracking on small punch creep testing of a vacuum plasma-sprayed CoNiCrAlY coating (2016)
Journal Article
Chen, H., Hyde, T., Voisey, K., & McCartney, D. (2018). Effects of pre-cracking on small punch creep testing of a vacuum plasma-sprayed CoNiCrAlY coating. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications, 232(3), 242-249. doi:10.1177/1464420715622495

This paper presents the results of small punch creep testing (SPCT) of a vacuum plasma-sprayed (VPS) CoNiCrAlY coating (Co – 31.7%, Ni – 20.8%, Cr – 8.1%, Al – 0.5%, Y, all in wt%) carried out at 750 grad. C. Coating cross-sections, after initial hea... Read More about Effects of pre-cracking on small punch creep testing of a vacuum plasma-sprayed CoNiCrAlY coating.

Laser drilling of via micro-holes in single-crystal semiconductor substrates using a 1070nm fibre laser with millisecond pulse widths (2015)
Journal Article
Maclean, J. O., Hodson, J. R., & Voisey, K. T. (2015). Laser drilling of via micro-holes in single-crystal semiconductor substrates using a 1070nm fibre laser with millisecond pulse widths. Proceedings of SPIE, 9657, Article 965704. https://doi.org/10.1117/12.2175898

© 2015 SPIE. Micro-machining of semiconductors is relevant to fabrication challenges within the semiconductor industry. For via holes for solar cells, laser drilling potentially avoids deep plasma etching which requires sophisticated equipment and co... Read More about Laser drilling of via micro-holes in single-crystal semiconductor substrates using a 1070nm fibre laser with millisecond pulse widths.