COLD SPRAY - Cold Gas Dynamic Spray

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 bars 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.

 

cold spray - projection à froid
 Source: 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.

Mallard implements and masters this technology since 2012, strengthening its innovative leadership position in this field of excellence: Thermal Spray coatings.

COLD SPRAY: Aluminium-Alumina alloy deposit

Technical characteristics of MALLARD Cold Spray:

• Carrier gas : Nitrogen or Helium
• Carrier gas temperature / Pressure: 1100 ° C / 50 bars
• Torch allowing spray into bores: Minimum diameter 84 mm
• Central feed unit
• Cooling system
• Specific nozzles adapted to different cases

All these characteristics allow us to use our Cold Spray under extreme conditions, with optimal results, including for non-ductile materials and / or difficult to project , and this, in particular environments.

We can also implement the Cold Spray in a “portable” version, with very high temperature and pressure levels.

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.  
• Additive Manufacturing  

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)
• Tantalum
• Zirconium 
• Zinc 
• Nickel 
• Cobalt 
• Silver  
• Bronze 
• Brass
• Etc …

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  
• Wear
• 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 (Refer to our Schneider Electric qualification for Cold Spray coatings), Aeronautic (Refer to our COLLINS / UTC Aerospace Systems qualification for Cold Spray coatings), 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: 

2-coldspray-en

Thickness Porosity
1.2 mm < 0.3%

Mallard, in partnership with the most prestigious and demanding clients, is involved in many innovative projects where the Cold spray is the solution allowing:

• Either to find answers to unsolved problems
• Either to bring an unmatched quality level of performance

This in perfect adequacy with our key business sectors:
• Energy / Rotating Machines
• Aerospace
• Chemical / Petrochemical

Who are the most "fond" of this new technology.

Characteristics of copper coating on steel substrate:

3-coldspray-en

Thickness As-sprayed Thickness Machined Hardness
8 mm 7.3 mm 125 HB

Aluminium-Alumina composite coating:

4-coldspray-en

Adhesion Porosity
40 MPa ~ 0.2%

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.

MALLARD, in this field of Additive Manufacturing, is involved in many major projects implementing international collaborations.

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 (almost 50 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...

Our Materials / Metallurgy laboratory is now operational…