scholarly journals Structural Transformation and Mechanical Properties of Cold Sprayed Nickel Coatings after Annealing

2008 ◽  
Vol 1151 ◽  
Author(s):  
Yu Zou ◽  
Ahmad Rezaeian ◽  
Jerzy Szpunar ◽  
Eric Irissou ◽  
Stephen Yue
Keyword(s):  
Cold Spray ◽  
Structural Transformation ◽  
Large Strain ◽  
Cold Spraying ◽  
Coating Technology ◽  
Spray Process ◽  
Nickel Coatings ◽  
Electron Backscattering Diffraction ◽  
Continuous Recrystallization ◽  
Bond Interface

ABSTRACTCold spray is a relatively new coating technology in which coatings can be produced by powdered particles under large plastic deformation without significant heating. In this paper, nickel coatings were fabricated by cold spray process followed by heat treatment in inert gas. Structural transformation of both as-sprayed and annealed coatings was investigated by Electron Backscattering Diffraction (EBSD) in a FEG-SEM. The results show that after cold spraying sub-micron grains and subgrains with high crystal strain appear in the particle bond interface, but not shown in the center of particles. Microstructure was transformed to be uniform and stresses were released after annealing in 400°C for one hour. And ductility and formability were significantly improved due to recovery and recrystallization. Continuous recrystallization after large strain deformation could occur after cold spraying followed by annealing.

Structures and Properties of Laser-Assisted Cold-Sprayed Aluminum Coatings

2016 ◽  
Vol 879 ◽  
pp. 984-989 ◽  
Author(s):  
Heli Koivuluoto ◽  
Andrea Milanti ◽  
Giovanni Bolelli ◽  
Jyrki Latokartano ◽  
Francesco Marra ◽  
...  
Keyword(s):  
Cold Spray ◽  
Cold Spraying ◽  
Cost Effective ◽  
Deposition Efficiency ◽  
Solid Particles ◽  
Aluminum Coatings ◽  
Spray Process ◽  
Structures And Properties ◽  
High Kinetic Energy ◽  
Laser Heated

In the cold spray process, solid particles impact on a surface with high kinetic energy, deform plastically and form a coating. This enables the formation of pure and dense coating structures. Even more, coating performance and deposition efficiency can be improved by assisting the process with a laser. Laser-assisted cold spraying (LACS) has shown its potential to improve coating properties compared with traditional cold spraying. In this study, coating quality improvement was obtained by using a co-axial laser spray (COLA) process which offers a new, cost-effective laser-assisted cold spray technique, for high-quality deposition and repair. In the COLA process, the sprayed surface is laser heated while particles hit the surface. This assists the better bonding between particles and substrate and leads to the formation of tight coating structures. This study focuses on the evaluation of the microstructural characteristics and mechanical properties (e.g., hardness and bond strength) of LACS metallic coatings.

Investigation of Cold Sprayed NiCoCrAlY Bond Coating

2009 ◽  
Vol 79-82 ◽  
pp. 863-866 ◽  
Author(s):  
Xiang Bo Li
Keyword(s):  
Cold Spray ◽  
High Speed ◽  
Cold Spraying ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Bond Coating ◽  
Spray Process ◽  
High Speed Impact ◽  
Helium Gas

In this paper, NiCoCrAlY coating was deposited by cold spraying with helium gas under the temperature of 500°C and pressure of 2.6 MPa. The microstructure of the coating was characterized through surface morphology and cross-sectional microstructure by scanning electron microscopy and X-ray diffraction analysis. The results showed that the coating is deposited through intensive plastic deformation of the spray particles by high-speed impact, and no oxygen phenomena discovered in the cold spray process. We also detected the micro-hardness using the Digital Vickers Microhardness Tester. Result revealed that a compact texture and high micro-hardness NiCoCrAlY coating can be obtained by cold spray.

Al-Limestone and Al-Granite Composites Prepared by Cold Spraying

2017 ◽  
Vol 891 ◽  
pp. 537-541
Author(s):  
Andrea Kollarovičová ◽  
Naďa Beronská ◽  
Pavol Štefánik ◽  
Karol Iždinský
Keyword(s):  
Cold Spray ◽  
Cold Spraying ◽  
Particle Sizes ◽  
Matrix Composites ◽  
High Velocity Impact ◽  
Spray Process ◽  
Porous Microstructure ◽  
Al Powder ◽  
Limestone Rock ◽  
Aluminium Metal

Two types of aluminium metal matrix composites (Al-MMCs) were prepared by cold spray process. The first Al-MMC was reinforced with granite rock and the second was reinforced with limestone rock particles. Al powder and rock powders (granite or limestone) were mixed to homogeneous mixtures and sprayed onto the Al substrate. The microstructure of as-sprayed composites was compared with microstructure of MMCs reinforced with commercially available Al2O3. The microstructures of Al-MMCs reinforced with granite and limestone were affected by hardness of rocks, particle sizes and compositions of the mixture. The coating is formed through high velocity impact of solid powders. The diameter of Al powder was about 30 μm and diameters of rock powders were from 5 to100 μm. Rock particles are distributed uniformly through the coating, maintaining their irregular morphologies. However, some large sized particles cracked and fragmented. The powder porosity was approximately 2.3 % for both types of Al-MMCs. Porous microstructure leads to lower critical velocity. The results indicate that, introducing irregular morphologies and/or pores into the feedstock. High quality metallic coatings can be more easily deposited by cold spray.

Investigation of the Splat Deposition Behavior onto a Composite Coating in Cold Spray

2018 ◽  
Vol 941 ◽  
pp. 1639-1644
Author(s):  
Xin Chu ◽  
Phuong Vo ◽  
Stephen Yue
Keyword(s):  
Electron Microscope ◽  
Composite Coating ◽  
Cold Spray ◽  
Spray Deposition ◽  
Cold Spraying ◽  
Single Component ◽  
Optical Profilometry ◽  
Deposition Behavior ◽  
Polished Substrate ◽  
Scanning Electron

The splat test is usually generated by low feed rate cold spraying of particles onto an as-polished substrate and it can be considered as a monolayer coating deposition. In this study, in order to investigate cold spray deposition mechanisms, Fe splats were sprayed onto the cold-sprayed single component 316L, Fe, and a composite 90Fe coatings. Results showed that although there is only 3.6 vol.% of 316L in the composite 90Fe coating, Fe splats exhibit a much better deposition behavior onto the 90Fe as compared with the single component Fe coating. To explain this observation, Fe splat samples were characterized using the scanning electron microscope (SEM), optical profilometry, splat adhesion tests, and splat nanoindentation. Finally, a preliminary explanation towards the Fe splat deposition behavior onto the composite coating was drawn.

scholarly journals SPH modeling of adhesion in fast dynamics: Application to the Cold Spray process

2016 ◽  
Vol 344 (4-5) ◽  
pp. 211-224 ◽  
Author(s):  
Paul Profizi ◽  
Alain Combescure ◽  
Kahuziro Ogawa
Keyword(s):  
Cold Spray ◽  
Cold Spray Process ◽  
Spray Process

Significant influence of carrier gas temperature during the cold spray process

2014 ◽  
Vol 30 (6) ◽  
pp. 443-450 ◽  
Author(s):  
S. Yin ◽  
X. Suo ◽  
H. Liao ◽  
Z. Guo ◽  
X. Wang
Keyword(s):  
Cold Spray ◽  
Significant Influence ◽  
Gas Temperature ◽  
Cold Spray Process ◽  
Carrier Gas ◽  
Spray Process

scholarly journals Deposition of Copper Fine Particle by Cold Spray Process

2009 ◽  
Vol 50 (6) ◽  
pp. 1482-1488 ◽  
Author(s):  
Masahiro Fukumoto ◽  
Hiroki Terada ◽  
Masahiro Mashiko ◽  
Kazunori Sato ◽  
Motohiro Yamada ◽  
...  
Keyword(s):  
Cold Spray ◽  
Fine Particle ◽  
Cold Spray Process ◽  
Spray Process

Micro-Porous Coatings and Enhanced CHF for Downward Facing Boiling During Passive Emergency Reactor Cooling

2016 ◽  
Author(s):  
Albert E. Segall ◽  
Faruk A. Sohag ◽  
Faith R. Beck ◽  
Lokanath Mohanta ◽  
Fan-Bill Cheung ◽  
...  
Keyword(s):  
Cold Spray ◽  
Heat Removal ◽  
Porous Coating ◽  
Porous Coatings ◽  
Spray Coatings ◽  
Spray Process ◽  
External Cooling ◽  
Loss Of Coolant Accident ◽  
Lower Head ◽  
Viable Approach

During a Reaction Initiated Accident (RIA) or Loss of Coolant Accident (LOCA), passive external-cooling of the reactor lower head is a viable approach for the in-vessel retention of Corium; while this concept can certainly be applied to new constructions, it may also be viable for operational systems with existing cavities below the reactor. However, a boiling crisis will inevitably develop on the reactor lower head owing to the occurrence of Critical Heat Flux or CHF that could reduce the decay heat removal capability as the vapor phase impedes continuous boiling. Fortunately, this effect can be minimized for both new and existing reactors through the use of a Cold-Spray delivered, micro-porous coating that facilitates the formation of vapor micro-jets from the reactor surface. The micro-porous coatings were created by first spraying a binary mixture with the sacrificial material then removed via etching. Subsequent quenching experiments on uncoated and coated hemispherical surfaces showed that local CHF values for the coated vessel were consistently higher relative to the bare surface. Moreover, it was observed for both coated and uncoated surfaces that the local rate of boiling and local CHF limit varied appreciably along the outer surface. Nevertheless, the results of this intriguing study clearly show that the use of Cold Spray coatings could enhance the local CHF limit for downward facing boiling by more than 88%. Moreover, the Cold-Spray process is amenable to coating the lower heads of operating reactors.

Multi-walled carbon nanotube-reinforced copper nanocomposite coating fabricated by low-pressure cold spray process

2012 ◽  
Vol 206 (16) ◽  
pp. 3488-3494 ◽  
Author(s):  
Seungchan Cho ◽  
Kenta Takagi ◽  
Hansang Kwon ◽  
Dowon Seo ◽  
Kazuhiro Ogawa ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Cold Spray ◽  
Low Pressure ◽  
Nanocomposite Coating ◽  
Cold Spray Process ◽  
Spray Process ◽  
Multi Walled Carbon Nanotube

scholarly journals Microstructure, Mechanical Properties and Corrosion Behavior of the Aluminum Alloy Components Repaired by Cold Spray with Al-Based Powders

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1633
Author(s):  
Zhiyi Zhang ◽  
Xiaoguang Sun ◽  
Shiming Huang ◽  
Xiaohui Han ◽  
Ping Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Cold Spray ◽  
Corrosion Behavior ◽  
High Speed ◽  
Neutral Salt ◽  
Cold Spray Process ◽  
Spray Process ◽  
High Speed Trains ◽  
Mechanical Properties And Corrosion

Aluminum alloy components of high-speed trains have a great risk of being corroded by various corrosive medium due to extremely complex atmospheric environments. This will bring out huge losses and reduce the safety and stability of trains. In order to solve the problem, cold spray process was used for repairing the damage of the aluminum alloy components with Al-based powders. Microstructure, mechanical properties and corrosion behavior were studied. The results indicated that there were very few pores and cracks in the repaired areas after repairing. The average microhardness of the repaired areas was 54.5 HV ± 3.4 HV, and the tensile strength of the repaired samples was 160.4 MPa. After neutral salt spray tests for 1000 h, the rate of mass loss of the samples repaired by cold spray was lower than that of 6A01 aluminum alloy. The electrochemical test results showed that the repaired areas had a higher open circuit potential than 6A01 aluminum alloy. As a result, the repaired areas such as the anode protected its nearby substrate. The samples repaired by cold spray exhibited better corrosion than 6A01 aluminum alloy. Cold spray process and Al-based powders are applicable for repairing the aluminum alloy components of high-speed trains.

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