scholarly journals Pre-heat treatment of gas atomized Al 2024 powder and its effects on the properties of cold spray coatings

2019 ◽  
Author(s):  
Lauren Elizabeth Randaccio
Keyword(s):  
Heat Treatment ◽  
Cold Spray ◽  
Spray Coatings ◽  
Al 2024

Effects of Post-spray Heat Treatment on Hardness and Wear Properties of Ti-WC High-Pressure Cold Spray Coatings

2018 ◽  
Vol 27 (7) ◽  
pp. 1153-1164 ◽  
Author(s):  
Jonathan Tang ◽  
Gobinda C. Saha ◽  
Peter Richter ◽  
Ján Kondás ◽  
Alberto Colella ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
Cold Spray ◽  
Wear Properties ◽  
Spray Coatings ◽  
Post Spray Heat Treatment

Metallurgical Approach for the Development of Heat Treatment Applied to 316L Stainless Steel Cold Spray Coatings

2021 ◽  
Author(s):  
Laury-Hann Brassart ◽  
Anne-Françoise Gourgues-Lorenzon ◽  
Jacques Besson ◽  
Francesco Delloro ◽  
David Haboussa ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cold Spray ◽  
Heat Treatments ◽  
Recrystallization Temperature ◽  
Scanning Calorimetry ◽  
Spray Coatings ◽  
Treatment Conditions ◽  
Long Time ◽  
Temperature Ranges ◽  
Sprayed Coatings

Abstract Industries developing cold-spray processes aim at producing dense and resistant coatings. Controlling microstructure and inter-particular fracture characteristics of sprayed coatings is essential to improve their properties. To do so; post-spraying heat treatment is a promising approach. This work addresses the development of such heat treatments and focuses on the analysis of recovery and recrystallization. Different heat treatment parameters were explored; namely; holding temperature and time; heating rate; and heating method. This approach revealed a competition between recrystallization and other microstructural evolution mechanisms; such as precipitation and porosity coalescence. An optimized heat treatment; allowing microstructural softening and adequate mechanical properties; was sought after. First; differential scanning calorimetry measurements applied to as-sprayed coatings enabled to identify recovery and recrystallization temperature ranges. Then; a variety of heat treatments was applied; involving long-time isothermal holdings as well as shorter cycles. Microstructure analysis and hardness measurements allowed making a first selection of treatment conditions.

Cold Spray of Al-MMC Coatings on Magnesium Alloys for Improved Corrosion and Wear Resistance

2009 ◽  
Vol 618-619 ◽  
pp. 377-380 ◽  
Author(s):  
Kevin Spencer ◽  
Daniel Fabijanic ◽  
Ming Xing Zhang
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Cold Spray ◽  
Spray Deposition ◽  
Salt Spray ◽  
Mg Alloys ◽  
Al Alloy ◽  
Artificial Ageing ◽  
Spray Coatings ◽  
Wear And Corrosion

Cold spray coatings are considered promising for surface protection of Mg alloys from wear and corrosion since the process temperature is low enough to avoid oxidation of the Mg or any adverse affects on artificial ageing heat treatments. A special version of cold spray known as Kinetic Metallization has been used to produce pure Al and Al alloy metal matrix composite (MMC) coatings on AZ91 Mg alloy substrates in the present work. This surface treatment produces dense coatings with high adhesive and cohesive strength, which have substantially higher hardness and wear resistance than the AZ91 substrate material. The influence of coating composition and subsequent heat treatment on wear and corrosion performance have been investigated, using pin-on-disc wear tests, salt spray testing and electrochemical polarisation techniques. The heat treatment of the cold spray coatings is compatible with the solutionising and T6 ageing heat treatment of AZ91Mg. The results show that cold spray deposition of MMC coatings is a simple and effective technique for improving the surface properties of Mg alloys, both in the as-cast and in the heat treated condition

Novel Powder Modification Method for the Cold Spray of Hard Steels

2021 ◽  
Author(s):  
D. Poirier ◽  
Y. Thomas ◽  
B. Guerreiro ◽  
M. Martin ◽  
M. Aghasibeig ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cold Spray ◽  
Steel Powder ◽  
Deposition Efficiency ◽  
Maximum Temperature ◽  
Powder Size ◽  
H13 Tool Steel ◽  
Treatment Conditions ◽  
Dense Deposits ◽  
Modification Method

Abstract A novel powder modification method based on the simultaneous softening and agglomeration of steel powders via heat treatment in a rotary tube furnace has been investigated as a means to improve the cold sprayability of H13 tool steel powder. By adjusting starting powder size and shape as well as heat treatment conditions (maximum temperature, cooling rate, and atmosphere), cold spray of H13 powder went from virtually no deposition to the production of thick dense deposits with a deposition efficiency of 70%. Powder agglomeration, surface state, microstructure evolution, and softening are identified as key factors determining powder deposition efficiency and resulting deposit microstructure.

Investigation into the Effects of High Temperature on Mechanical Properties of Thermal Spray Coatings Applied by Plasma Spraying

2018 ◽  
Vol 284 ◽  
pp. 1151-1156
Author(s):  
Lenar N. Shafigullin ◽  
A.R. Ibragimov ◽  
A.I. Saifutdinov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Thermal Spray ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Thermal Spray Coatings ◽  
Spray Coatings ◽  
Heat Treatment Of Coatings ◽  
Double Heat Treatment

C. C. Berndt advanced investigations of mechanical properties of thermal spray coatings under 4-point bending. He found that this investigation method is sensitive to the mechanical properties of thermal spray coatings.This paper contains the detailed investigation results for thermal spray coatings of zirconium dioxide under 4-point bending, i.e. tests of the specimens subjected to spraying at varying conditions and pre-test soaking with the various duration at 1100 °С.It was established how the mechanical properties of thermal spray coatings changed depending on the spraying mode and high temperature soaking. The test results show that the double heat treatment of coatings is more preferable than one-time heat treatment as it make the properties change linearly. It is more easily controllable during operation of the components with thermal spray coating.

Optimization of laser cladding of cold spray coatings with B4C and Ni powders

2017 ◽  
Author(s):  
V. M. Fomin ◽  
A. A. Golyshev ◽  
A. G. Malikov ◽  
A. M. Orishich ◽  
A. A. Filippov ◽  
...  
Keyword(s):  
Cold Spray ◽  
Laser Cladding ◽  
Spray Coatings

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.

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