Coating Properties

The AlumiPlate coating has been extensively tested and shown to significantly outperform all other cadmium alternatives. Also, it is well proven as a higher performing replacement for IVD aluminum and is the only aluminum coating that can be anodized thus enabling anodization of a wide variety of non-aluminum substrates.  AlumiPlate coatings have no Cr6+, no Ni, no Zn, no Cd, they are pure Al.

Purity – electroplated aluminum is 99.99% pure.  The coating is free of alloying elements, with extremely low levels of contaminants and impurities.  Purity is monitored on a regular basis using high resolution Glow Mass Discharge Spectrometry (GDMS). For representative purity data, see our semiconductor applications page.

Thickness – The AlumiPlate® Al plating process can deposit very thin or thick layers – very uniformly.  Applications requiring thick layers for subsequent machining or material build-up for parts salvage can benefit from the process.  Engineered components are routinely plated with thicknesses of 0.0001″ – 0.015″ (2 – 400 µm), or more.

Coefficient of Thermal Expansion (CTE) & Cryogenic Use – Electroplated aluminum provides protection at cryogenic temperatures for commonly used engineered materials.  Substrates that have significantly different CTE to electroplated Al benefit from the plating’s low internal stress, high ductility and excellent adhesion. Electroplated aluminum parts have been used in scientific devices operating at cryogenic temperatures.

Torque & Tension – With a surface friction modifier, Al electroplated fasteners have consistent, low dispersion and predictable torque/tension properties.  Testing for fasteners in military applications show electroplated Al fasteners match the surface properties of cadmium plated fasteners, while providing improved corrosion protection and minimizing embrittlement concerns.  The surface modifier and resultant tightening torque factor can be engineered to offer a “drop-in” solution for your fastener application.

Internal Stresses – Unlike other plating processes, electroplated aluminum has very low internal stresses.  It is an excellent choice for very thin parts that require corrosion protection but are susceptible to warping from highly stressed coatings.  Electroplated aluminum has been used to plate foils as well.

High Temperature Resistance – The melting point of aluminum is 1,220ºF (660º C).   AlumiPlate aluminum will protect surfaces from corrosion at significantly higher temperatures than virtually any other conventional plated metal.

  • Significant testing by the aerospace industry has shown that AlumiPlate aluminum plating is able to withstand and retain its beneficial high strength steel protection properties up to 350° C.
  • Semiconductor industry extensive testing for their short duration high temperature applications have verified excellent AlumiPlate performance up to 370° C.

Unlike many conventional plating systems which are destroyed or lost at higher temperatures, AlumiPlate aluminum offers excellent protection for base metals in high temperature applications.

Electrical Conductivity – The electrical conductivity of AlumiPlate aluminum is approximately 62% that of copper and is one of the best conductors of all of the non-precious metals.  AlumiPlate aluminum also can offer better materials compatibility than expensive gold and silver coatings for many applications.  It has been well tested in electrical connector environments as a cadmium replacement and has passed all conductivity requirements.

Thermal Conductivity – AlumiPlate aluminum has three times the thermal conductivity of steel and can be used as a thermally conductive, corrosion resistant coating which can offer excellent matching of thermal expansion coefficients and materials compatibility.  High-purity AlumiPlate aluminum has near superconductivity at temperatures approaching Absolute Zero.

Ductility / Formability – Aluminum is a soft and ductile metal.  Elongation of over 50% without fracture has been measured. Depending on the basis metal and the intermediate layers, if any, the AlumiPlate layer can be bent, flexed, stretched, rolled or drawn without cracking or peeling.  This excellent malleability makes AlumiPlate the perfect choice for corrosion protection applications requiring forming and crimping after plating.

Density – The dense non-porous character of AlumiPlate Al is a unique property of the amorphous, pore-free coating structure, and one of several differences between the electrodeposited AlumiPlate layer and ion vapor-deposited aluminum (IVD Al).  A thin 0.0003″ (8 µm) layer ensures a pore-free aluminum coating and acts as a barrier to protect the underlying material, contributing to the plating’s outstanding corrosion resistance.  Unlike IVD Al, shot-peening densification is not necessary.  The plating’s structure and capability for controlled thick layers enable the use of all common Al finishing techniques for non-Al materials.  For example, Al electroplated steel and copper can be anodized or chemically polished, just like Al 6061.

Ductility of electrodeposited aluminum is very high. This layer was deposited on copper foil & bent 180° with no cracks or fissures (ASTM B-489).

Uniformity – As an electrolytic plating process, Al plating follows the same physical rules governing other electroplating processes such as Cd or Zn.  In other words, if a component is currently Cd plated, electroplated Al offers an immediate “drop-in” replacement with similar uniformity and control.  Unlike other “line-of-sight” processes, Al electroplating can be used for complex geometries and inside surfaces (see Throwing Power for more information).  Critical semiconductor and aerospace parts that require tight plating control are excellent candidates for the process.

Throwing Power – Because the AlumiPlate Al plating process is a true electrodeposition process done in a liquid bath, parts with complex geometries and small (~0.25″) inside diameters can be plated with an even layer of aluminum.  The throwing power of AlumiPlate aluminum is equal to, or better than that of electrolytic cadmium.  Through the use of supplemental anode racking, the AlumiPlate process can plate into small holes where the depth exceeds two diameters.

Adhesion – Al electroplated parts have excellent adhesion and can be expected to pass all destructive and non-destructive adhesion tests listed in ASTM B-571 (Standard Practice for Qualitative Adhesion Testing of Metallic Coatings).  Because of its high temperature capability, it is also possible to test the plating adhesion at high temperatures (30 minutes at 300 C for example).  Such a high temperature bake constitutes a severe test of adhesion and typically cannot be done on other platings.

Anodizability – The pore-free coating allows AlumiPlate plated parts to be clear or hard-coat anodized.  AlumiPlate aluminum can be plated onto and anodized on nearly any conductive substrate including but not limited to steels, copper, aluminum alloys, stainless alloys, beryllium and metal matrix composite materials and other various alloys.  Part geometries such as blind holes and/or intricate interior surfaces can typically pose challenges for anodizability applications and, because AlumiPlate has excellent uniformity in tough geometric conditions using its rack plating process, many otherwise difficult or impossible anodizing opportunites have been solved using the AlumiPlate coating.

The aluminum oxide layer formed by anodizing is non-conductive and can be a good electrical insulator, especially in high temperature applications.  The ability to change an electroplated surface from electrically conductive to non-conductive is unique to AlumiPlate aluminum.

Furthermore, the layer obtained from the anodized Al electroplating is purer and more consistent than that of anodized Al alloys. Anodized electroplated aluminum has shown increased corrosion protection (HCl bubble testing), higher breakdown voltage and significantly lower levels of contaminants, for semiconductor use.

The capability to permanently color the surface of anodized aluminum makes the AlumiPlate layer an attractive choice for a wide variety of appearance or performance reasons.  The coloring could be used to color-code different types of components.  Applications abound where aesthetics play an important role such as in the Marine, Recreation, Automotive, Decorative, Sporting Goods, Die Casting, Jewelry and many other industries.

Fatigue -the soft and malleable AlumiPlate aluminum coating has a very low notch sensitivity factor resulting in no significant fatigue debit.  This has been well tested in critical load parts such as aircraft landing gear components.

Contact us for more information or to discuss your application in more detail.