COLD SPRAY - Cold Gas Dynamic Spray
COLD SPRAY is a thermal spray process operating at low temperatures: solid metal powders are accelerated to very high speeds on new or repairing parts by a pressurized carrier gas (up to 50 bar and 1100°C). During impact with the substrate, powder particles undergo plastic deformation and adhere to the surface, ensuring the quality of the deposit.
A converging - diverging nozzle enables the expansion of the gas up to ambient pressure, allowing the gas acceleration to a supersonic velocity and its cooling to a temperature below 100°C. The powders, injected into the convergent part of the nozzle, are accelerated up to 1200 m/s, allowing a strong adhesion at the point of impact and thus a high quality coating without oxidation.
Courtesy of impact innovations
With this new technology, MALLARD has increased the know-how in one of its key area: the Metallizing. This specificity is enhanced by our ability to prepare surfaces before coating and, of course, to machine/grind after coating. We consider that the perfect knowledge of a thermal spray process is inseparable from the global expertise of our company.
The COLD SPRAY process has many advantages over the other thermal spray coating deposition methods:
- Thick coating (several mm)
- High density coatings - no porosity (close to theoretical density of material)
- Microstructural integrity of the substrate and the coating material
- No oxidation due to the process low temperature
- High mechanical properties (adhesion/cohesion strength)
- High deposition efficiency - recycling of residual powders
- Simplified preparation and masking.
The COLD SPRAY process is a versatile process allowing the deposition of usual and unconventional powder:
- Copper and alloys
- Aluminum and alloys
- Titanium and alloys
- Ferromagnetic and Stainless steels
- Cermet (mixture ceramic-metal)
And the deposition can be made on wide panel of metallic, ceramic and polymer substrates.
By its benefits, Cold Spray method is mainly used to solve the problems such as, but not limited to:
- High corrosion
- Heat transfer
- Electrical conductivity
- Repair on sensitive materials
Moreover, Cold Spray is very efficient to repair on either new parts or maintenance parts, especially on sensitive material components, with cutting edge technology applications.
MALLARD is already present and has proven its skills and expertise in many high technology areas: Energy, Aeronautic (Refer to our new Hamilton Sundstrand qualification for alu-alumine coatings by Cold Spray), Mechanics, Chemistry, Petrochemicals...
The COLD SPRAY offers a good alternative to the deposition under controlled atmosphere, with a less expensive and less complex process.
Metallographic cross-section view of Aluminum coating deposited on steel substrate by Cold Spray
Characteristics of copper coating on steel substrate:
COLD SPRAY is by definition an additive manufacturing process, since it involves building a coating by successive stacking of micrometric particles. Beyond the field of thermal spraying, the COLD SPRAY process is a good candidate for the production of complex parts by additive manufacturing (ie 3D Printing). Indeed, technological advances in the field of CAM and robotics offer new perspectives to the COLD SPRAY process.
ADDITIVE MANUFACTURING by cold spray process:
Source: impact innovations
With the mastery of this powerful and innovative technology, MALLARD is the first French company that offers its customers all industrial thermal spray processes known to date.
MALLARD guarantees the use of the best suited technical means in line with the desired coating, as the adequacy between materials and process is essential for us.
With the COLD SPRAY process, MALLARD is stepping ahead and enriches its know-how, performance, reliability and long experience of the metallization (+ 40 years).
Since its establishment in 2012, our Cold Spray is increasingly requested by our industrial partners in diverse and unexpected areas.
MALLARD is at the heart of innovation in high-tech fields such as aerospace, energy, nuclear, with a constant work in partnership to research and development of specific applications in Cold Spray. Indeed, MALLARD has already deposited patents for design and construction of equipment in aeronautics, fulfilling the very strict specifications of this field.
We are strong in our ability to respond to requests / ambitious issues, involving unusual substrates/coatings materials.
MALLARD sees far away where the COLD SPRAY pushes the limits...