Anodized, Plated And Galvanized Surfaces; Cordless Right Angle Drill - Thermo Scientific XL2 User Manual

Anodized, Plated and Galvanized Surfaces

Cordless Right Angle Drill

Thermo Scientific
Remember to follow safe techniques for handling and disposing of solvents and cleaning rags
Anodizing is the process of polarizing the metal surface into a passive state which protects it
against corrosion. This process is most often applied to aluminum alloys.
Galvanized steel is one of the most common of the coated surfaces. In this process, steel is
passed through a molten bath of a zinc alloy. Zinc reacts with the steel metal to form a
bonding layer on the steel surface. The zinc layer does not separate from the steel and forms a
protective layer that protects the steel from oxidation.
Galvanized layers are relatively thick compared to other plating elements and methods. When
grinding to remove the zinc coating, you will find increased zinc values even when you can see
the steel surface. Grind a little further and zinc values will disappear. Zinc clings to the surface
of the sanding disc, so you will need to frequently change discs.
Electroplating is another common practice of applying a coating which not only protects the
surface from oxidation, but also improves the base material's wear resistance, lubricity and
improves the overall aesthetics of the product. The electroplated coating is generally thinner
and more evenly applied than galvanizing. Electroplating has a wide range of elements and in
some situations there may be two or more different coatings on the same part.
The following is a partial list of elements that are used to plate the surface of base metals:
Ni, Cr, Cadmium (Cd), Tin (Sn), Zn, Al
This style of drill is recommended for most surface preparation in the field because it gives the
operator the greatest amount of control, and thus safety, when grinding samples. When
moving a sanding disc on a conventional drill over a sample, forces tend to produce
movement the operator may find difficult to control. Control and stability are important in
grinding from effectiveness and safety perspectives.
A cordless right angle drill similar to the one pictured below is recommended for light to
medium surface removal. For materials with heavy oxidation such as carbon and low alloy
steel, an angle grinder, explained in the next section, is recommended. A kit with the drill,
batteries and charging units, can be purchased from ThermoFisher, or companies such as
DeWalt, Hitachi, Makita, Milwaukee or Ryobi.
5
Common Operations
Metal Sample Prep
Niton XL2 Analyzer User's Guide 51