Hardcoat anodizing (sometimes called hardcoating or hard anodizing) is an electro-chemical process of converting aluminum to aluminum oxide. This process allows the production of a thicker wear and corrosion resistant coating on a variety of aluminum alloys.
      These hard coatings allow the use of aluminum in many design applications formerly restricted to steel. Hardcoat anodizing offers a variety of beneficial properties:

Key Benefits

1. The Hardcoat surface is harder than file-hard (62 RC and varies with alloy)
      Coating hardness is usually determined by a point loading indention test. This test is not an accurate measurement of hardcoat hardness because the coating tends to crush under concentrated point loading due to the softer under-metal(aluminum). A more viable andfrequently used test to evaluate hardness is the Vickers Micro Hardness Test, which can be converted to a Rockwell equivalency reading.

2. Hardcoat resists corrosion
      Our test results on 6061 aluminum indicated that the Hardcoat treated surface withstood corrosion in a five percent salt spray test for 336 hours.
We recommend that you submit a sample of the alloy and a description of the finish you intend to use. it will be processed and returned to you for evaluation.

3. Hardcoat can be colored
      Applied at thinner coating thickness (.0005 - .001), Hardcoat anodize can be color dyed with any colors currently in stock (red, blue, gold, green and black).

4. Hardcoat will extend the working life of your product
      Commonly used on rollers, guides, trays and anything that requires a hard, damage resistant surface.

Capacities

Tank Sizes
      Our current size limits for Hardcoat processing is 11.5' x 5' x 4'.

Materials
      Hardcoat processing can only be applied to aluminum alloys. Although most aluminum alloys can be processed, those with a low copper content (less than 3.5%) and a low silicon content (less than 5%) are recommended. We've found the best results occur on 6061, 6262 and 7075 wrought alloys; 355, 356 cast alloys and 319 die cast alloys.

Dissimilar Materials
      Aluminum parts which have dissimilar materials installed in them such as steel helicoils, bushings, dowel pins, ect. should not be installed prior to processing. However these material can be masked using the best available techniques, but this type of processing can only be done at the customers risk.

Coating thickness and specification guideliunes

      Hardcoat anodizing may be provided in thicknesses ranging from a few ten-thousandths of an inch upto .0025", depending on the alloy and the application. Like coatings, hardcoat anodizing changes the dimensions of the basic part; although, unlike plating, only half of the hardcoat is buildup (the other half is penetration). For example, .002" hardcoat consists of .001" penetration and .001" added to the original dimension. Therefore, in machining the part, it is essential to allow for the change and to request a specific oxide thickness on blueprints and/or purchase orders.

      When developing a hardcoat-anodizing specification, it is important to consult with your anodizer to ensure receipt of a satisfactory product. Consider the following:

The application of the component

Environment of use

The aluminum alloy and temper

Corrosion and hardness requirements

Thickness range of the film

Final dimensional tolerances

Optimum location for contact points (i.e., racking)

Approval requirements and/or other standards.