Bimetal Composite

AlCunnect enables

MATERIAL-LOCKED JOIN

Realization of a material-locked join of aluminium and copper

EXCELLENT MECHANICAL ADHESION

Excellent mechanical adhesion through metallurgical bond of the aluminium and copper world

CUSTOMIZABLE PROPORTIONS

Customizable proportions at buyer’s choice

CORROSION PROTECTION

Optional corrosion protection can help to prevent the corrosive effects of water or salts.

Benefits of AlCunnect

COST REDUCTION POTENTIAL

Cost reduction potential by replacing the expensive copper with aluminium

WEIGHT REDUCTION

Achieving a weight reduction through use of aluminium instead of copper

ELECTRICAL CONDUCTIVITY

Attainment of a good electrical conductivity

TEMPERATURE STABILITY

Attainment of a good temperature stability up to 200°C

Bimetal Composite Material Alcunnet

Innovative clad metal made of aluminium and copper

Current market trends and the ongoing weight reduction efforts in the automotive industry, as well as increased requirements on heat dissipation in power electronics leads to innovative approaches in companies participating as solution providers for these industries.

DODUCO has responded to these trends early and worked on joining the metals copper and aluminium together using cold roll bonding. The combination of these metals can yield to cost savings, through the replacement of expensive copper with aluminium. Additionally, it is possible to obtain a significant reduction in weight through the use of the light metal aluminium. AlCunnect provides a reliable connection of the copper and aluminium world.

DODUCO has already reached an advanced stage of development with the copper/aluminium bonding and is looking for partners to successfully establish the bimetal AlCunnect in the market.

Benefits and properties of the Metal Composite AlCunnect

Now that it is possible to combine aluminium and copper numerous new opportunities arise with our metal composite AlCunnect.

Copper is well-known for its high electrical conductivity but has become a very costly raw material due to price increases over the past years.

The aluminium copper bimetal enables cost benefits as a result of partially replacing copper with aluminium.

Aluminium has the fourth best electrical and thermal conductivity of all metals. Only silver, copper and gold are better. Although copper outperforms aluminium in both disciplines, it is still heavier and more expensive. For the same conductance the cross-section of aluminium is 1.6 times larger than the cross-section of copper, even though it weighs only half as much.

Another positive aspect of using the clad metal AlCunnect, beside the cost benefits, is the resulting significant weight reduction, which is important in the automotive sector. At the same time the plated bimetal of aluminium and copper provides temperature stability up to 200°C and an excellent mechanical adhesion.

Three different kinds of the Bimetal AlCunnect

AlCunnect is a composite material prepared by cold roll plating of Aluminium and Copper. Subsequent heat treatment ensures a strong metallurgical bond between the metals. AlCunnect is offered in three different variants to meet customers’ individual needs. First, the overlap composite, where copper and aluminium strips are joined together along one side. Second, the overlay composite, where aluminium and copper are clad together. Third, the inlay composite, where a strip of copper is plated onto an aluminium carrier strip. Optional corrosion protection can help to prevent the corrosive effects of water or salts.

Overlap composite

In the so-called overlap composite AlCunnect is composed of copper- and aluminium-strips joined together.

The overlapped plated strip material can be produced with a total maximum width of 4.7” (120mm) and a thickness of up to 0.08” (2mm). At the same time the width of the overlapping section of aluminium and copper strips is approximately 0.2” (5mm). The width ratio of the aluminium and copper strips is individually selectable. The overlap composite is available in coil form.

Applications for the Overlap Composite AlCunnect

Overlap Composite proportions

Overlap Composite
Total width	Up to approx. 4.72“ (120mm)
Thickness	Up to approx. 0.08“ (2mm)
Width of overlap zone	Approx. 0.2” (5mm)’
Width ratio Al/Cu	Different combinations possible

Overlay composite

The overlay plated alternative of the bimetal AlCunnect is produced by cladding the entire surfaces of aluminium and copper together.

These aluminium-copper slugs are available with a width of up to 8” (200mm) and total thickness up to 0.4” (10 mm). The thickness ratio of aluminium and copper is freely selectable.

Applications for the overlay composite AlCunnect

Overlay composite proportions

Overlay composite
Width	Up to approx. 7.9” (200mm)
Thickness ratio Al/Cu	Different combinations possible
Total thickness	Up to approx. 0.4“ (10mm)

Copper inlay composite

For this variant, a copper strip is plated onto an aluminium carrier strip. DODUCO has decades of experience and high levels of process expertise in strip plating. The inlay composite reduces materials cost by limiting the use of copper to essential points. This process provides extensive cost savings alongside improved material properties, including better mechanical connectivity than flowing movement aluminium.

Applications of the inlay composite:

Overview of Dimensions

Inlay composite
Width	up to 120 mm / 4.72“
Thickenesses	up to 2 mm / 0.08“
Inlay width	up to 5 mm to 100% / 0.2“
Copper Inlay thickness	min. 20µm max. up to 25%

Corrosion protection

If copper and aluminium are in close proximity to each other, just a little bit of moisture can be enough to set a corrosion process in motion. Specifically for such circumstances DODUCO has already developed methods for corrosion protection. There are two different possibilities, the inorganic and organic coating processes to protect AlCunnect against the environmental influences.

The electroplated and isolating coatings have been qualified in cooperation with leading suppliers of the automotive industry by DIN salt spray tests.

Organic corrosion protection

Coating with an isolating lacquer is one possible method for corrosion protection of bimetal AlCunnect. The specifically developed lacquer can be applied fully or selectively in a continuous reel-to-reel plating process onto the clad material AlCunnect. The short curing time and wide temperature range for applications are special features for this type of corrosion protection.

Inorganic corrosion protection

Electroplating is a further method used to counter corrosion. In this process the aluminium-copper metal composite is fully or selectively plated on a reel-to-reel plating line. For the inorganic corrosion protection tin has proved to be effective.

Al-Si-plated strips

Especially in power electronics and the automotive industry, bondable surfaces are needed for the connection of carrier materials with electronic components. DODUCO has many years of experience in the field of roll-bonded strips with aluminum-silicon inserts and looks forward to your inquiries.

Bimetal Comp­osite