Kermetico HVAF industrial equipment provides a cost-effective way to deposit 50+ µm (0.002” +) thick conductive coatings of copper and aluminum onto electronic components.
Our HVAF copper coatings are characterized by less than 1% porosity, low (0.30-0.40 wt.%) oxygen level, high (>75 MPa | 10,000 PSI) adhesion and electrical resistivity of 0.03 micro-Ohm*m. They could be used as a heat conductive coating in electronic packaging devices, brazing layers over aluminum heat sinks and high electrical conductivity layers.
Preventing Galvanic, Bimetallic or Contact Corrosion with Coatings
Bimetallic corrosion is also referred to as a galvanic corrosion, dissimilar metal corrosion or contact corrosion.
Bimetallic corrosion occurs when two metals with different potentials, are in electrical contact while immersed in an electrically conducting corrosive liquid. Because the metals have different natural potentials in the liquid, a current will flow from the anode (more electronegative) metal to the cathode (more electropositive), which will increase the corrosion on the anode.
In general, the reactions which occur are similar to those that would occur on single, uncoupled metal, but the rate of attack is increased, sometimes dramatically.
Preventing liquid from an appearance at the point of contact mitigates galvanic corrosion. HVAF sprayed Cu on Al surfaces provide this result.
OOur HVAF equipment deposits bulk-like Al, Cu, brass and bronze coatings up to several millimeters thick. They exhibit excellent machinability (turning, grinding, finishing) and are as engravable as electroplated copper.
Kermetico HVAF equipment deposits up to 10 kg (22 lbs.) of copper coating per hour, offering the shortest production time.
Good solderability and heat conductivity of our coatings allow their use for heat sinks in power electronic applications.
HVAF High Velocity Thermal Spraying of Low Oxidation Coatings of Copper, Bronze and Brass Alloys
A Micrograph of a Kermetico HVAF Copper Conductive Coating
We have a time-proven approach for the high velocity thermal spray application of copper coatings with the Kermetico HVAF SL thermal spray system.
Our systems allow the deposition of copper and its alloys, including brass, bronze and some individual grades like Cu-In-Ga.
High heat conductivity copper application onto balls and other spherical parts with thicknesses of 6-mm (0.240”) and more is an easy task for the Kermetico HVAF SL system.
A customer requested the application of a high electrical conductivity copper layer with a particular pattern, 0.2 mm (0.008”) thick and the width of each band was about 2.5 mm (0.100”).
The first approach used machining and milling the copper coating to achieve the required pattern.
The Kermetico HVAF Copper coating behaves as a “solid” metal during machining. And milling through the coating down to the substrate was performed without the remaining copper layer delaminating. (This should give you some idea about the bonding and cohesive strength of the copper coating.)
Bond strength measurements report over 11,000 PSI (over 75 MPa) on carbon steel, the majority related to breaking the glue used for ASTM 633C testing.
Spraying of brass and bronze thermal spray coatings is even simpler than the pure copper.
The Kermetico HVAF SL Specialized System for High Velocity Thermal Spraying Low Melting Point Materials: Al, Cu and Alloys
Our HVAF SL is a unique system, specially developed for depositing non-oxidized, dense aluminum, copper and alloyed low melting point metal coatings.
Kermetico HVAF SL for Low Melting Point Metals
Key features:
- Axial powder injection
- Protection against feedstock oxidation
- No material evaporation in the coating process
- No nozzle clogging
- Uniform, dense, high-bond aluminum, tin, copper and copper alloys coatings
- High spray rate:
- 6 kg/hour (13 lbs./hour) for Al coating
- 10 kg/hour (22 lbs./hour) for Cu, bronze and brass coatings
- Blast & spray operation capable
- Industrial-grade, automated, portable air-cooled system
HVAF Thermal Spray of Dense Non-Oxidized Aluminum Coatings
Our HVAF temperatures melt aluminum. But an oxygen depleted flame and inert gas prevent Al from oxidizing, both in the jet and on the surface, and the high-speed jet creates a high bond and low porosity coating, so our HVAF SL system deposits excellent quality Al coatings.
And we make Al coatings with no nozzle clogging and no oxides in the coating structure.
Blast and spray with the Kermetico High Velocity Guns
Each Kermetico gun can operate in the blast and spray operations.
You can eliminate blasting and masking for blasting in a blast booth or cabinet
Just prepare a part for coating, blast it with the Kermetico HVAF gun (it is extremely fast and uniform) and spray with the same gun after switching the powder feed hose and perhaps changing the nozzle.
It is much faster and more accurate than a compressed air blasting.
With HVAF blasting you spend one tenth the time and one hundredth the grit for blasting in comparison with conventional compressed air blasting.
Our customers and we have been successfully doing this with thousands of parts.
The Kermetico HVAF Low Melting Point Process Description
The HVAF SL Gun sprays powders, heated and accelerated by the air-fuel gas combustion products.
The mixture of compressed air and the chosen fuel gas flows into the combustion chamber through the orifices of a catalytic ceramic insert.
The initial ignition results in the heating of the insert above the mixture’s auto-ignition temperature, and then the hot insert continuously ignites the mixture.
When entering the gun, the compressed air cools the chamber and the nozzle assembly.
Then part of the preheated air is mixed with the chosen fuel gas and combusted.
The spray powder is injected axially into a wide combustion chamber.
The powder exiting the chamber is propelled into the nozzle of chosen length and configuration, where the gas flow accelerates it to a velocity that may be over 1,000 m/s.
When impacting a substrate, the spray powder particles form a coating.
Kermetico HVAF Equipment
Kermetico designs and manufactures three families of HVAF thermal spray equipment.
- Convertible HVOF and HVAF equipment:
- Multi-purpose HVAF AK systems, with a range of spray guns:
- AK7 – a high-power gun for the thermal spray of large parts
- AK6 – a universal gun to spray a balanced mix of parts in a job shop
- AK5 – a compact gun to spray smaller parts, thin walls and complex surfaces
- AK-ID – an 80 mm (3.15”) and larger internal diameter spray gun
- AK-IDR – a rotating ID gun to spray 4” (100 mm) and larger bores
- AK-HH – a handheld gun for on-site coating
- Specialized HVAF S equipment:
- Additional equipment:
- An HVAF grit feeder for the grit blast preparation of parts to reduce coating costs
- A Gas Permeability Tester for an instant check of a coating’s through porosity
Kermetico Inc. – HVAF Material Science Excellence, Equipment Manufacturing and Thermal Spray Coating Services Since 2006
We create equipment that helps material scientists, engineers, and business managers achieve their goals.
We have installed more than 60 Kermetico HVAF systems in the USA, Europe, Japan, and China.
Some of the systems are at work in Universities and National Labs, but most of them are used in production thermal spray shops.
We proudly design and produce our HVAF thermal spray equipment in California and install it all over the world.
You can visit our R&D center in Benicia to meet our designers and to see our HVAF equipment in action.
We also provide HVAF and HVOF thermal spray coating services – ourselves and through our network of partners.
