Color Titanium Anodizing Applications
Titanium anodizing is widely used for biomedical and medical equipment cleaning. The main benefit of color titanium anodizing is color coding to assist doctors and physicians with identifying differences in size or anatomical shape of surgical implants. Examples of anodizing titanium include: trauma bone fixation plates have different color drill guides to indicate the anatomical difference between left & right plates and bone screws used in spinal fusion surgery are anodized different colors to indicate differences in length.
Titanium Anodizing Equipment & Tanks
Titanium Oxide Layers
The “illusion of color” is the simplest way to explain color titanium anodizing. More specifically, color titanium anodization is a manipulation of the oxide layer on the surface of titanium. An oxide layer naturally forms on the surface of titanium upon exposure to the atmospheric conditions and oxygen reacts with the surface of titanium.
This process of oxidation naturally occurs with many elements and the small protective oxide layer helps protect it from further reactions to air or water. When the oxide layer first forms, it is about 1-2 nanometers thick or 10-20 angstroms, but it will continue to grow to 25 nanometers (250 angstroms) thick in open air.
Titanium Oxide Layer Thickness Controlled with Electrochemical Processing
This thickness of the oxide layer is the fundamental premise of “illusion of color”. The thickness of the oxide layer can be varied by cleaning & prepping the titanium in various chemistries and using electrical current to it build the oxide layer. This electrolytic electro-chemical process varies the oxide layer thickness resulting in different wavelengths of visible light reflected / refracted off the surface of titanium part. Various wavelengths of light determines which visible color is reflected to the viewer hence the “illusion of color”. For example, the color bronze can be achieved by building the oxide layer thickness to about 300 to 350 angstroms and color green can be achieved with and oxide layer of 500 to 550 angstroms thick.
Ti Anodize Color Samples
Titanium Anodizing Equipment – Process Stability
Since the titanium anodize process manipulates the oxide layer, there are various factors that can have a large impact on the formation & uniformity of the oxide layer and subsequently the consistency of the appearance of color. Properly processing the parts in titanium anodizing equipment specifically made for color titanium anodizing drastically helps control the process to achieve consistent titanium colors.
Surface finish is one of the biggest factors that can affect the appearance of color. If the part is machined poorly, some of the surface areas can become work harden or smeared and in this case the color not to be consistent. This results in like a magenta coloration with gold spots. Surface preparation is also very important to achieving consistent color. It is important to prep the surface in a way that the oxide layer will be created evenly.
Titanium Anodizing Chemistry Blends Cleaning and Electrochemical Electrolytes
Various chemistries are used in titanium anodizing equipment to properly prepare a part for consistent surface finish and thus consistent oxide layer formation. Best Technology and its partners have developed custom chemical blends of solutions and electrolytes that greatly increase the manufacturing yield of this process which are not offered by anyone else in industry.
Medical device manufacturers have enlisted Best Technology’s expertise for process design and development with anodizing equipment that is safely design for use with the required chemistries.
Best Technology has the experience and the resources to build Ti anodize tanks, equipment and develop processes for Ti anodizing equipment for processes large and small. Colored titanium anodizing is an “illusion of color” achieved by insuring consistent surface finish, building and manipulating the oxide layer. Let our application engineers design a titanium anodizing line for your products today!