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Cold spray additive manufacturing (CSAM) is a solid-state deposition process well-suited to titanium that has the potential to make large, near-net-shape parts at high productivity. However, further research is required to truly accomplish the freedom of design expected from CSAM and, in particular, to address how to manufacture a specific 3D object with minimal porosity. Therefore, this paper focuses on understanding how tool path planning strategy and robot kinematics affect the geometry and porosity distribution in a 3D object. Square titanium frames were manufactured layer-by-layer using a continuous tool path planning strategy in which the contour spray angle, traverse speed and corner smoothing radius were varied selectively. The sample geometry was analysed by 3D laser scanning, and the capacity to produce straight, vertical walls and square corners were demonstrated. The total porosity in the manufactured objects was measured using the Archimedes’ principle, further investigated by metallographic cross-section analysis, and then validated by X-ray computed tomography on selected samples. Porosity was distributed layer by layer, creating a fishbone structure in the cross-section with higher porosity between the layers and near the edges of the walls and corners. The influence of robot kinematics and toolpath planning on forming underbuilt and overbuilt structures and how they influenced porosity development are also discussed. The knowledge generated from this research can significantly influence the development of tool path planning strategies in CSAM, providing the means to produce improved near-net-shapes with controlled porosity formation.
Alejandro Vargas-Uscategui; Peter C. King; Sam Yang; Clement Chu; Jianli Li. Toolpath planning for cold spray additively manufactured titanium walls and corners: Effect on geometry and porosity. Journal of Materials Processing Technology 2021, 298, 117272 .
AMA StyleAlejandro Vargas-Uscategui, Peter C. King, Sam Yang, Clement Chu, Jianli Li. Toolpath planning for cold spray additively manufactured titanium walls and corners: Effect on geometry and porosity. Journal of Materials Processing Technology. 2021; 298 ():117272.
Chicago/Turabian StyleAlejandro Vargas-Uscategui; Peter C. King; Sam Yang; Clement Chu; Jianli Li. 2021. "Toolpath planning for cold spray additively manufactured titanium walls and corners: Effect on geometry and porosity." Journal of Materials Processing Technology 298, no. : 117272.
Cold spray is emerging as an additive manufacturing technique, particularly advantageous when high production rate and large build sizes are in demand. To further accelerate technology’s industrial maturity, the problem of geometric control must be improved, and a neural network model has emerged to predict additively manufactured geometry. However, limited data on the effect of deposition conditions on geometry growth is often problematic. Therefore, this study presents data-efficient neural network modelling of a single-track profile in cold spray additive manufacturing. Two modelling techniques harnessing prior knowledge or existing model were proposed, and both were found to be effective in achieving the data-efficient development of a neural network model. We also showed that the proposed data-efficient neural network model provided better predictive performance than the previously proposed Gaussian function model and purely data-driven neural network. The results indicate that a neural network model can outperform a widely used mathematical model with data-efficient modelling techniques and be better suited to improving geometric control in cold spray additive manufacturing.
Daiki Ikeuchi; Alejandro Vargas-Uscategui; Xiaofeng Wu; Peter King. Data-Efficient Neural Network for Track Profile Modelling in Cold Spray Additive Manufacturing. Applied Sciences 2021, 11, 1654 .
AMA StyleDaiki Ikeuchi, Alejandro Vargas-Uscategui, Xiaofeng Wu, Peter King. Data-Efficient Neural Network for Track Profile Modelling in Cold Spray Additive Manufacturing. Applied Sciences. 2021; 11 (4):1654.
Chicago/Turabian StyleDaiki Ikeuchi; Alejandro Vargas-Uscategui; Xiaofeng Wu; Peter King. 2021. "Data-Efficient Neural Network for Track Profile Modelling in Cold Spray Additive Manufacturing." Applied Sciences 11, no. 4: 1654.
In cold spray additive manufacturing (CSAM), the severe plastic deformation of the input powder particles leads to an accumulation of residual stresses, the magnitude of which is affected by process conditions. In the current study, the effects of traverse speed and powder feed rate on the residual stress state were investigated in commercially pure titanium cylinders produced by CSAM. Residual stress measurements were made in a grid pattern covering the 2D cross section using the KOWARI neutron diffractometer at ANSTO, Australia, and selected results were validated using the contour method. It was found that the thermal effect was dominant on the residual stress state generating a tensile state near the inner and outer surfaces of the cylinder walls while compressive residual stresses tend to accumulate in the center of the wall. The residual stresses were dominated by thermal stresses at low traverse speed, while peening becomes more critical at high traverse speeds. Increasing the powder feed rate increased the magnitude of the residual stresses. High traverse speeds and low feed rates are beneficial for producing 3D parts by CSAM. However, slow traverse speeds are more detrimental than high feed rates for a given layer thickness.
Alejandro Vargas-Uscategui; Peter King; Mark J. Styles; Michael Saleh; Vladimir Luzin; Kevin Thorogood. Residual Stresses in Cold Spray Additively Manufactured Hollow Titanium Cylinders. Journal of Thermal Spray Technology 2020, 29, 1508 -1524.
AMA StyleAlejandro Vargas-Uscategui, Peter King, Mark J. Styles, Michael Saleh, Vladimir Luzin, Kevin Thorogood. Residual Stresses in Cold Spray Additively Manufactured Hollow Titanium Cylinders. Journal of Thermal Spray Technology. 2020; 29 (6):1508-1524.
Chicago/Turabian StyleAlejandro Vargas-Uscategui; Peter King; Mark J. Styles; Michael Saleh; Vladimir Luzin; Kevin Thorogood. 2020. "Residual Stresses in Cold Spray Additively Manufactured Hollow Titanium Cylinders." Journal of Thermal Spray Technology 29, no. 6: 1508-1524.
Cold spray additive manufacturing is an emerging technology that offers the ability to deposit oxygen-sensitive materials and to manufacture large components in the solid state. For further development of the technology, the geometric control of cold sprayed components is fundamental but not yet fully matured. This study presents a neural network predictive modelling of a single-track profile in cold spray additive manufacturing to address the problem. In contrast to previous studies focusing only on key geometric feature predictions, the neural network model was employed to demonstrate its capability of predicting complete track profiles at both normal and off-normal spray angles, resulting in a mean absolute error of 8.3%. We also compared the track profile modelling results against the previously proposed Gaussian model and showed that the neural network model provided comparable predictive accuracy, even outperforming in the predictions at cold spray profile edges. The results indicate that a neural network modelling approach is well suited to cold spray profile prediction and may be used to improve geometric control during additive manufacturing with an appropriate process planning algorithm.
Daiki Ikeuchi; Alejandro Vargas-Uscategui; Xiaofeng Wu; Peter C. King. Neural Network Modelling of Track Profile in Cold Spray Additive Manufacturing. Materials 2019, 12, 2827 .
AMA StyleDaiki Ikeuchi, Alejandro Vargas-Uscategui, Xiaofeng Wu, Peter C. King. Neural Network Modelling of Track Profile in Cold Spray Additive Manufacturing. Materials. 2019; 12 (17):2827.
Chicago/Turabian StyleDaiki Ikeuchi; Alejandro Vargas-Uscategui; Xiaofeng Wu; Peter C. King. 2019. "Neural Network Modelling of Track Profile in Cold Spray Additive Manufacturing." Materials 12, no. 17: 2827.
Cold spray is a solid-state rapid deposition technology in which metal powder is accelerated to supersonic speeds within a de Laval nozzle and then impacts onto the surface of a substrate. It is possible for cold spray to build thick structures, thus providing an opportunity for melt-less additive manufacturing. Image analysis of particle impact location and focused ion beam dissection of individual particles were utilized to validate a 3D multicomponent model of cold spray. Impact locations obtained using the 3D model were found to be in close agreement with the empirical data. Moreover, the 3D model revealed the particles’ velocity and temperature just before impact—parameters which are paramount for developing a full understanding of the deposition process. Further, it was found that the temperature and velocity variations in large-size particles before impact were far less than for the small-size particles. Therefore, an optimal particle temperature and velocity were identified, which gave the highest deformation after impact. The trajectory of the particles from the injection point to the moment of deposition in relation to propellant gas is visualized. This detailed information is expected to assist with the optimization of the deposition process, contributing to improved mechanical properties for additively manufactured cold spray titanium parts.
M. Faizan-Ur-Rab; S. H. Zahiri; Peter King; C. Busch; Syed Masood; M. Jahedi; Romesh Nagarajah; Stefan Gulizia. Utilization of Titanium Particle Impact Location to Validate a 3D Multicomponent Model for Cold Spray Additive Manufacturing. Journal of Thermal Spray Technology 2017, 26, 1874 -1887.
AMA StyleM. Faizan-Ur-Rab, S. H. Zahiri, Peter King, C. Busch, Syed Masood, M. Jahedi, Romesh Nagarajah, Stefan Gulizia. Utilization of Titanium Particle Impact Location to Validate a 3D Multicomponent Model for Cold Spray Additive Manufacturing. Journal of Thermal Spray Technology. 2017; 26 (8):1874-1887.
Chicago/Turabian StyleM. Faizan-Ur-Rab; S. H. Zahiri; Peter King; C. Busch; Syed Masood; M. Jahedi; Romesh Nagarajah; Stefan Gulizia. 2017. "Utilization of Titanium Particle Impact Location to Validate a 3D Multicomponent Model for Cold Spray Additive Manufacturing." Journal of Thermal Spray Technology 26, no. 8: 1874-1887.
Two X-ray computed tomography (CT) datasets have been acquired for a cold-sprayed titanium sample before and after heat treatment. The datasets were collected with a beam energy of 30 keV at the Australian Synchrotron. Three-dimensional (3D) distributions of porosity in the Ti sample were reconstructed using a data-constrained modelling (DCM) technique. Quantitative analysis indicated that the heat treatment caused morphological changes to the pores and a small decrease in the overall porosity. After heat treatment, some fine porosity disappeared while the large porosity regions were essentially unaffected except for a change towards a more rounded pore shape. Interconnectivity between pores was reduced, which has implications for sealing and trapping of contaminant gases in cold-sprayed parts. The characterization technique and the workflow presented in the paper are applicable to non-destructive 3D characterization of other materials.
Y.Q. Ren; Peter King; Y.S. Yang; T.Q. Xiao; C. Chu; Stefan Gulizia; Anthony Murphy. Characterization of heat treatment-induced pore structure changes in cold-sprayed titanium. Materials Characterization 2017, 132, 69 -75.
AMA StyleY.Q. Ren, Peter King, Y.S. Yang, T.Q. Xiao, C. Chu, Stefan Gulizia, Anthony Murphy. Characterization of heat treatment-induced pore structure changes in cold-sprayed titanium. Materials Characterization. 2017; 132 ():69-75.
Chicago/Turabian StyleY.Q. Ren; Peter King; Y.S. Yang; T.Q. Xiao; C. Chu; Stefan Gulizia; Anthony Murphy. 2017. "Characterization of heat treatment-induced pore structure changes in cold-sprayed titanium." Materials Characterization 132, no. : 69-75.
Zinc (Zn) and copper (Cu) are strong inhibitors of bacterial biofilms in aqueous solutions, but are known toxins of crustaceans. A new metal application method; cold-sprayed metal embedment, known to modulate metal release, was tested for its applications in crustacean larval culture systems. Cold-spray technology allows metal particles to bond to plastics, while modulating metal ion release and biocide activity to the substrate boundary. In this study, Eastern spiny lobster (Sagmariasus verreauxi) larvae (phyllosoma) were cultured in the presence of cold-sprayed Zn and Cu metal surfaces. Metal loss was monitored gravimetrically on embedded surfaces, assessment of water ion concentrations and analysis of phyllosoma body content were undertaken. Phyllosoma moulting, deformity and mortality patterns were monitored. Cold-sprayed Zn- and Cu-embedded surfaces were depleted with losses of 0.69% and 31.2% noted respectively. Culture water concentrations of these metals were elevated and accumulation by phyllosoma occurred. Water Zn concentrations of 18.5 μg L−1 were associated with chronic eyestalk moult deformities; the first report of Zn causing a non-lethal moult deformity in crustacean larvae. The Cu surface lost a third of its metal mass with a water concentration of 40 μg L−1 causing acute toxicity and localization of composite granules in the midgut gland. Cu associated mortality was noted by Day 2 of culture with a LD 50 experienced by Day 9. Future work on the use of bioactive metals in aquaculture systems will focus on a range of different metal alloys, and improved modulation of ion release mechanisms through increased particle embedment depth and separation.
Gregory G Smith; Andrew J Poole; Peter C King; Stephen Battaglene; Quinn FitzGibbon; Rocky De Nys. The release and uptake of metals from potential biofilm inhibition products during spiny lobster (Sagmariasus verreauxi,H. Milne Edwards 1851) culture. Aquaculture Research 2015, 48, 608 -617.
AMA StyleGregory G Smith, Andrew J Poole, Peter C King, Stephen Battaglene, Quinn FitzGibbon, Rocky De Nys. The release and uptake of metals from potential biofilm inhibition products during spiny lobster (Sagmariasus verreauxi,H. Milne Edwards 1851) culture. Aquaculture Research. 2015; 48 (2):608-617.
Chicago/Turabian StyleGregory G Smith; Andrew J Poole; Peter C King; Stephen Battaglene; Quinn FitzGibbon; Rocky De Nys. 2015. "The release and uptake of metals from potential biofilm inhibition products during spiny lobster (Sagmariasus verreauxi,H. Milne Edwards 1851) culture." Aquaculture Research 48, no. 2: 608-617.
In this chapter, the physics involved in cold spray is presented in order to get an understanding of the fundamentals that govern this complex spray process. After an overview of the process basics, the process parameters that influence the process outcome, namely the coating quality through the particle impact velocity, are introduced as well as an overview of materials that are known to be sprayable by cold spray. This is followed by a detailed description of compressible fluid dynamics theory, which is at the heart of the cold spray process, allowing to better understand why the nozzle geometry, gas pressure and gas temperature are the most crucial parameters in cold spray amongst all the spray parameters. This is followed by a complete description of the bonding physics involved in cold spray that includes a comprehensive review of the critical velocity concept and its prediction for various materials. It also includes a detailed description of the adiabatic shear instability phenomena that is present in cold spray when particles impact the substrate as well as a thorough review of the numerical models and results used to gain a better understanding of this complex process of particle deformation and bonding, including localized nanosize features.
P. King; M. Yandouzi; B. Jodoin. The Physics of Cold Spray. Modern Cold Spray 2015, 31 -72.
AMA StyleP. King, M. Yandouzi, B. Jodoin. The Physics of Cold Spray. Modern Cold Spray. 2015; ():31-72.
Chicago/Turabian StyleP. King; M. Yandouzi; B. Jodoin. 2015. "The Physics of Cold Spray." Modern Cold Spray , no. : 31-72.
Biofilm formation on membranes during water desalination operation and pre-treatments limits performance and causes premature membrane degradation. Here, we apply a novel surface modification technique to incorporate anti-microbial metal particles into the outer layer of four types of commercial polymeric membranes by cold spray. The particles are anchored on the membrane surface by partial embedment within the polymer matrix. Although clear differences in particle surface loadings and response to the cold spray were shown by SEM, the hybrid micro-filtration and ultra-filtration membranes were found to exhibit excellent anti-bacterial properties. Poly(sulfone) ultra-filtration membranes were used as for cross-flow filtration of Escherichia coli bacteria solutions to investigate the impact of the cold spray on the material׳s integrity. The membranes were characterized by SEM–EDS, FT-IR and TGA and challenged in filtration tests. No bacteria passed through the membrane and filtrate water quality was good, indicating the membranes remained intact. No intact bacteria were found on hybrid membranes, loaded with up to 15 wt% silver, indicating the treatment was lysing bacteria on contact. However, permeation of the hybrid membranes was found to be reduced compared to control non-modified poly(sulfone) membranes due to the presence of the particles across the membrane material. The implementation of cold spray technology for the modification of commercial membrane products could lead to significant operational savings in the field of desalination and water pre-treatments.
Ludovic F. Dumée; Li He; Peter C. King; Maëlle Le Moing; Isabelle Güller; Mikel Duke; Peter D. Hodgson; Stephen Gray; Andrew J. Poole; Lingxue Kong. Towards integrated anti-microbial capabilities: Novel bio-fouling resistant membranes by high velocity embedment of silver particles. Journal of Membrane Science 2014, 475, 552 -561.
AMA StyleLudovic F. Dumée, Li He, Peter C. King, Maëlle Le Moing, Isabelle Güller, Mikel Duke, Peter D. Hodgson, Stephen Gray, Andrew J. Poole, Lingxue Kong. Towards integrated anti-microbial capabilities: Novel bio-fouling resistant membranes by high velocity embedment of silver particles. Journal of Membrane Science. 2014; 475 ():552-561.
Chicago/Turabian StyleLudovic F. Dumée; Li He; Peter C. King; Maëlle Le Moing; Isabelle Güller; Mikel Duke; Peter D. Hodgson; Stephen Gray; Andrew J. Poole; Lingxue Kong. 2014. "Towards integrated anti-microbial capabilities: Novel bio-fouling resistant membranes by high velocity embedment of silver particles." Journal of Membrane Science 475, no. : 552-561.
V. Lemiale; Peter King; Murray Rudman; M. Prakash; Paul Cleary; M.Z. Jahedi; Stefan Gulizia. Temperature and strain rate effects in cold spray investigated by smoothed particle hydrodynamics. Surface and Coatings Technology 2014, 254, 121 -130.
AMA StyleV. Lemiale, Peter King, Murray Rudman, M. Prakash, Paul Cleary, M.Z. Jahedi, Stefan Gulizia. Temperature and strain rate effects in cold spray investigated by smoothed particle hydrodynamics. Surface and Coatings Technology. 2014; 254 ():121-130.
Chicago/Turabian StyleV. Lemiale; Peter King; Murray Rudman; M. Prakash; Paul Cleary; M.Z. Jahedi; Stefan Gulizia. 2014. "Temperature and strain rate effects in cold spray investigated by smoothed particle hydrodynamics." Surface and Coatings Technology 254, no. : 121-130.
Particles of copper, bronze and zinc were embedded into a polymer using cold-spray technology to produce loading density gradients of metal particles. The gradients were used to identify the species with the highest tolerance to the release of copper and zinc ions. The gradients also established the minimum effective release rates (MERRs) of copper and zinc ions needed to prevent the recruitment of fouling under field conditions. Watersipora sp. and Simplaria pseudomilitaris had the highest tolerances to the release of metal ions. Copper and bronze gradient tubes were similar in their MERRs of copper ions against Watersipora sp. (0.058 g m−2 h−1 and 0.054 g m−2 h−1, respectively) and against S. pseudomilitaris (0.030 g m−2 h−1 and 0.025 g m−2 h−1, respectively). Zinc was not an effective antifoulant, with failure within two weeks. In conclusion, cold-spray gradients were effective in determining MERRs and these outcomes provide the basis for the development of cold-spray surfaces with pre-determined life-spans using controlled MERRs.
M.J. Vucko; P.C. King; A.J. Poole; Y. Hu; M.Z. Jahedi; R. De Nys. Assessing the antifouling properties of cold-spray metal embedment using loading density gradients of metal particles. Biofouling 2014, 30, 651 -666.
AMA StyleM.J. Vucko, P.C. King, A.J. Poole, Y. Hu, M.Z. Jahedi, R. De Nys. Assessing the antifouling properties of cold-spray metal embedment using loading density gradients of metal particles. Biofouling. 2014; 30 (6):651-666.
Chicago/Turabian StyleM.J. Vucko; P.C. King; A.J. Poole; Y. Hu; M.Z. Jahedi; R. De Nys. 2014. "Assessing the antifouling properties of cold-spray metal embedment using loading density gradients of metal particles." Biofouling 30, no. 6: 651-666.
Peter King; Christian Busch; Teresa Kittel-Sherri; Mahnaz Jahedi; Stefan Gulizia. Interface melding in cold spray titanium particle impact. Surface and Coatings Technology 2014, 239, 191 -199.
AMA StylePeter King, Christian Busch, Teresa Kittel-Sherri, Mahnaz Jahedi, Stefan Gulizia. Interface melding in cold spray titanium particle impact. Surface and Coatings Technology. 2014; 239 ():191-199.
Chicago/Turabian StylePeter King; Christian Busch; Teresa Kittel-Sherri; Mahnaz Jahedi; Stefan Gulizia. 2014. "Interface melding in cold spray titanium particle impact." Surface and Coatings Technology 239, no. : 191-199.
Cold spray metal embedment is an innovative antifouling (AF) technology that delivers metal particles with AF properties into many thermoplastic polymers. AF efficacy was quantified for low (22.1 ± 4.8 g m−2) and high (101.1 ± 10.8 g m−2) densities of copper particles embedded into polyurethane (PU) seismic streamer skins, which are used in geophysical exploration. Failure of each Cu-embedded treatment was defined as settlement of hard foulers. Low-density streamers failed after 42 days while high-density streamers failed after 210 days. Most importantly, the high-density streamers were completely free of hard foulers including the barnacle Amphibalanus reticulatus during this time period. In conclusion, cold-spray metal embedment is an effective AF technology for PU seismic streamer skins, under intense fouling conditions. Higher copper particle densities enhance AF longevity and the effect of density provides a tool to extend efficacy and enhance AF performance for specific polymers.
M.J. Vucko; Peter King; Andrew Poole; M.Z. Jahedi; Rocky de Nys. Polyurethane seismic streamer skins: an application of cold spray metal embedment. Biofouling 2012, 29, 1 -9.
AMA StyleM.J. Vucko, Peter King, Andrew Poole, M.Z. Jahedi, Rocky de Nys. Polyurethane seismic streamer skins: an application of cold spray metal embedment. Biofouling. 2012; 29 (1):1-9.
Chicago/Turabian StyleM.J. Vucko; Peter King; Andrew Poole; M.Z. Jahedi; Rocky de Nys. 2012. "Polyurethane seismic streamer skins: an application of cold spray metal embedment." Biofouling 29, no. 1: 1-9.
Cold spray was used to embed copper particles into 6 different polymers – polyurethane, high density polyethylene, polypropylene, nylon 6, polytetrafluoroethylene and polycarbonate – without coating buildup. During impact, penetration of the particles and polymer flow around them resulted in their capture by the surface. The effects of spray temperature and traverse speed on particle penetration, sample weight gain and polymer deformation were investigated. Average embedment depths were determined from cross-sections, and over 50 μm was measured in high density polyethylene and polyurethane. Tribological properties (roughness and self-friction coefficients) and electrical sheet resistance of the Cu-embedded surfaces were studied. The embedding technique may find utility in functionalizing polymer surfaces that do not withstand high temperature coating methods, which provide poor adhesion for paint films, or where flexibility of the polymer needs to be maintained.
Peter C. King; Andrew J. Poole; Susan Horne; Rocky de Nys; Stefan Gulizia; Mahnaz Z. Jahedi. Embedment of copper particles into polymers by cold spray. Surface and Coatings Technology 2012, 216, 60 -67.
AMA StylePeter C. King, Andrew J. Poole, Susan Horne, Rocky de Nys, Stefan Gulizia, Mahnaz Z. Jahedi. Embedment of copper particles into polymers by cold spray. Surface and Coatings Technology. 2012; 216 ():60-67.
Chicago/Turabian StylePeter C. King; Andrew J. Poole; Susan Horne; Rocky de Nys; Stefan Gulizia; Mahnaz Z. Jahedi. 2012. "Embedment of copper particles into polymers by cold spray." Surface and Coatings Technology 216, no. : 60-67.
The study demonstrates that embedment of copper particles into thermoplastic polymers (polymers) using cold spray technology is an effective deterrent against fouling organisms. Two polymers, high-density polyethylene (HDPE) and nylon were metallised with copper powder using cold spray technology. After 250 days in the field, Cu-embedded HDPE and copper plate controls were completely free of hard foulers compared to Cu-embedded nylon and polymer controls which were heavily fouled with both soft and hard fouling. Antifouling (AF) success is related to the interaction between the properties of the polymers (elastic modulus and hardness) and the cold spray process which affect particle embedment depth, and subsequently, the release of copper ions as determined by analytical techniques. Embedding metal using cold spray equipment is shown to be an effective AF technology for polymers, in particular those that are difficult to treat with standard AF coatings, with efficacy being a function of the interaction between the cold spray metal and the polymer recipient.
M.J. Vucko; Peter King; Andrew Poole; C. Carl; M.Z. Jahedi; Rocky de Nys. Cold spray metal embedment: an innovative antifouling technology. Biofouling 2012, 28, 239 -248.
AMA StyleM.J. Vucko, Peter King, Andrew Poole, C. Carl, M.Z. Jahedi, Rocky de Nys. Cold spray metal embedment: an innovative antifouling technology. Biofouling. 2012; 28 (3):239-248.
Chicago/Turabian StyleM.J. Vucko; Peter King; Andrew Poole; C. Carl; M.Z. Jahedi; Rocky de Nys. 2012. "Cold spray metal embedment: an innovative antifouling technology." Biofouling 28, no. 3: 239-248.
The dissolution of S-phase clusters in aluminium alloy 2024 (AA2024) exposed to a 0.5 μl seawater droplet is presented. Foils for transmission electron microscopy (TEM) were made from local attack sites using a focussed ion beam/scanning electron microscope (FIB/SEM). The sections showed that clusters of S-phase particles underwent dealloying. The resulting copper sponge morphology, banding, preferred orientation and crystal defect structure as a result of plastic deformation have been characterised. With build-up of amorphous corrosion product, physical and electrical isolation of parts of the clusters developed, with the result of copper dissolution from the S-phase remnants.
Peter C. King; Ivan S. Cole; Penny A. Corrigan; Anthony E. Hughes; Tim H. Muster; Sebastian Thomas. FIB/SEM study of AA2024 corrosion under a seawater drop, part II. Corrosion Science 2012, 55, 116 -125.
AMA StylePeter C. King, Ivan S. Cole, Penny A. Corrigan, Anthony E. Hughes, Tim H. Muster, Sebastian Thomas. FIB/SEM study of AA2024 corrosion under a seawater drop, part II. Corrosion Science. 2012; 55 ():116-125.
Chicago/Turabian StylePeter C. King; Ivan S. Cole; Penny A. Corrigan; Anthony E. Hughes; Tim H. Muster; Sebastian Thomas. 2012. "FIB/SEM study of AA2024 corrosion under a seawater drop, part II." Corrosion Science 55, no. : 116-125.
The role of metallic microstructure in 0.5 μl seawater droplet corrosion of aluminium alloy 2024 (AA2024) has been investigated. Focussed ion beam/scanning electron microscopy (FIB/SEM) was used to determine the relationships between the corrosion products formed at specific sites at the surface and the underlying attack mechanisms. Dealloying of S-phase particles, matrix/particle interfacial attack and grain boundary attack were the predominant attack modes. Cooperative behaviour between IM particles was made possible by networks of etched grain boundaries, which provided a connecting path.
Peter C. King; Ivan Cole; Penny A. Corrigan; Anthony E. Hughes; Tim Muster. FIB/SEM study of AA2024 corrosion under a seawater drop: Part I. Corrosion Science 2011, 53, 1086 -1096.
AMA StylePeter C. King, Ivan Cole, Penny A. Corrigan, Anthony E. Hughes, Tim Muster. FIB/SEM study of AA2024 corrosion under a seawater drop: Part I. Corrosion Science. 2011; 53 (3):1086-1096.
Chicago/Turabian StylePeter C. King; Ivan Cole; Penny A. Corrigan; Anthony E. Hughes; Tim Muster. 2011. "FIB/SEM study of AA2024 corrosion under a seawater drop: Part I." Corrosion Science 53, no. 3: 1086-1096.
Cold spray was used to deposit conductive aluminium coatings onto lead zirconate titanate (PZT) piezoceramics. The optimisation of processing parameters was explored. Grain removal from the PZT surface due to the impact of Al particles was reduced by increasing the average particle velocity. Surface domain reorientation was detected by X-ray diffraction (XRD). Substrate temperatures during spraying were maintained at a low level by controlling the upstream, cold spray temperature and robot movement. The electrical resistance of the cold sprayed aluminium was 9.9 ± 0.5 μΩ cm. The impedance characteristics of poled specimens were shown to be unchanged by cold spray.
Peter C. King; Saden Zahiri; Mahnaz Jahedi; James Friend. Aluminium coating of lead zirconate titanate—A study of cold spray variables. Surface and Coatings Technology 2010, 205, 2016 -2022.
AMA StylePeter C. King, Saden Zahiri, Mahnaz Jahedi, James Friend. Aluminium coating of lead zirconate titanate—A study of cold spray variables. Surface and Coatings Technology. 2010; 205 (7):2016-2022.
Chicago/Turabian StylePeter C. King; Saden Zahiri; Mahnaz Jahedi; James Friend. 2010. "Aluminium coating of lead zirconate titanate—A study of cold spray variables." Surface and Coatings Technology 205, no. 7: 2016-2022.
Peter C. King; Mahnaz Jahedi. Relationship between particle size and deformation in the cold spray process. Applied Surface Science 2010, 256, 1735 -1738.
AMA StylePeter C. King, Mahnaz Jahedi. Relationship between particle size and deformation in the cold spray process. Applied Surface Science. 2010; 256 (6):1735-1738.
Chicago/Turabian StylePeter C. King; Mahnaz Jahedi. 2010. "Relationship between particle size and deformation in the cold spray process." Applied Surface Science 256, no. 6: 1735-1738.
The effect of cold spray temperature and substrate hardness on particle deformation and adhesion has been studied, with particular emphasis on adiabatic shearing leading to melting. Copper particles were cold sprayed onto commercial purity (CP) aluminum and alloy 7050-T7451, with stagnation temperatures 200, 400, and 600 °C. Deposition efficiency, assisted by particle embedding, increased with temperature and was higher on the softer CP substrate. Crater surfaces, adhered particles, and interfaces were characterized by scanning electron microscopy, focused ion beam, and transmission electron microscopy. For comparison, the impact of 15 μm Cu particles was simulated using finite element modeling. A thin layer of material on the substrate-side of the interface was predicted to reach melting point on both substrates at higher impact velocities. Formation of a molten layer was found experimentally. At 600 °C, the effect of substrate heating by the gas jet could not be ignored.
Peter C. King; Gyuyeol Bae; Saden H. Zahiri; Mahnaz Jahedi; Changhee Lee. An Experimental and Finite Element Study of Cold Spray Copper Impact onto Two Aluminum Substrates. Journal of Thermal Spray Technology 2009, 19, 620 -634.
AMA StylePeter C. King, Gyuyeol Bae, Saden H. Zahiri, Mahnaz Jahedi, Changhee Lee. An Experimental and Finite Element Study of Cold Spray Copper Impact onto Two Aluminum Substrates. Journal of Thermal Spray Technology. 2009; 19 (3):620-634.
Chicago/Turabian StylePeter C. King; Gyuyeol Bae; Saden H. Zahiri; Mahnaz Jahedi; Changhee Lee. 2009. "An Experimental and Finite Element Study of Cold Spray Copper Impact onto Two Aluminum Substrates." Journal of Thermal Spray Technology 19, no. 3: 620-634.