Titanium polishing is an important aspect of the surface finish of titanium parts and involves several techniques. This mainly involves removing material from the surface of the titanium part to smooth it. Polishing the titanium metal part improves intrinsic properties such as biocompatibility, strength, corrosion resistance, wear resistance and high temperature resistance.
Although there are benefits, polishing titanium must be done gradually to avoid mistakes and unwanted results. Therefore, this article introduces titanium polishing to help you understand how titanium is polished and how the process is applied in titanium-using industries.
What is titanium polishing?
Titanium polishing involves using buffing wheels and polishing wax to reduce roughness while improving the surface appearance of a titanium part. After machining the titanium, the titanium part is polished to provide additional protection and a better surface finish (leaving a Ra value of 0.1-0.05 microns).
Furthermore, the polishing process offers a high level of control as it allows you to polish small and complex titanium parts with great precision. However, the final color and texture of the finished piece may vary depending on the condition of the unpolished titanium and the type of sandpaper used.
How do you polish titanium to a mirror finish?
Like most surface finishing techniques, polishing a titanium part is a simple process. Follow the steps below to complete the process:
Step 1: Degreasing and cleaning process
During the manufacture of titanium, residues of dirt, oil and grease can remain on titanium parts. Therefore, it is important to prepare the surface before any finishing process with the following sub-steps:
- Remove oil residues with degreasing agents, e.g.
- Fill a bowl with enough clean water;
- Immerse the titanium part in clean water;
- Add a small amount of your favorite cleaning product (e.g. mild soap, ammonia or window cleaner).
- Leave for a few minutes;
- Rinse with warm water and dry with a clean towel.
Note: Do not use chlorine, bleach or other chemicals that may affect the properties and aesthetic quality of the titanium piece.
Step 2: Grinding Process
Smooth the surface with sandpaper. The grinding process is similar to fine grinding. When sanding you remove the oxidized layer and a very thin layer of titanium. Sanding also improves the adhesion of the metal polish. To do this, proceed as follows:
- Apply a lubricant to the surface of the titanium part.
- Place the sandpaper on a hook attached to a drill.
You can use different grit sandpaper. Typically, you start with coarse grain and then work your way up to smooth grain. For example, you might start with 200-grit sandpaper, then move up to 800-grit sandpaper and go up to 2000-grit sandpaper, depending on how you want the surface to look. - Then, apply a lubricant to the sandpaper.
- Place it on one edge of the titanium plate and move it horizontally until it reaches the other edge.
Do this until you cover the entire surface of the piece. Repeat the process for the different sandpaper grains.
Note: It is important to apply gentle, even pressure to all areas of this part of the titanium marking to maintain consistent surface patterns.
Step 3: Polishing Process
The polishing process gives the object the desired shiny, glassy appearance. How to proceed:
- Clean the titanium surface with an alcohol-based cleaner.
- Polish the titanium surface with a metal polisher and buffing wheel. Apply water occasionally to reduce the heat generated.
Step 4 Final Finish
Even after polishing, marks may remain on the piece. To hide these tracks,
- Apply lacquer polish to a clean towel;
- Rub the area with the cleaner, exerting even pressure over the surface until it becomes visibly darker;
- Spray the surface with water and let it dry;
- Apply the sealant to another towel;
- Rub the towel on the titanium surface;
- Let it dry;
- Wipe off excess liquid with a clean towel.
Different types of surface processing when polishing titanium
Depending on the polishing force, speed and polishing disc used, different surface qualities result when polishing titanium in parts production:
Rough polishing
To roughly polish titanium parts, use a grinding wheel made of silicon oxide and titanium polishing wax. Polishing force is minimal. In rough polishing, it is better to round the corners of the titanium part.
Medium polish
Rough polishing can result in visible lines and a dull surface. Matte aluminum oxide grinding wheels and polishing wax can solve this. This increases the shine and smoothness of the surface.
Fine polishing
Fine polishing gives the titanium part a more reflective, i.e. thinner, surface. To do this, use a soft combed cotton buffing pad and mirror wax to apply more pressure to the surface of the piece.
Mirror polishing
Highly polished titanium parts have a mirror-like surface. You can achieve this with a soft, combed buffing wheel made of cotton and polishing wax. Typically, a buffing wheel is ideal because it allows you to polish hard-to-reach areas on your piece.
The benefits of polishing titanium parts
For many manufacturers, a good finishing process is as important as the manufacturing process itself. The titanium finish offers many benefits, including the following.
Improved aesthetics
The appearance of a product is as important as its function. Polished titanium is more usable and offers enhanced functionality. This is because a good surface polish improves the texture of a titanium part and gives the surface a professional shine.
Stronger electrical conductivity
Titanium is normally a poor conductor of electricity. However, electrical conductivity is one of the most important properties of a good metal part. If the surface polishing is good, electrical current can flow through the titanium part with little resistance. This makes polished titanium particularly useful in the automotive industry.
Optimize resistance
Corrosion not only renders a part unusable, but can also lead to the ultimate destruction of the metal. Although titanium metal is resistant to many chemical solutions, polishing improves its corrosion resistance.
Furthermore, a titanium part wears out easily, leading to the gradual deterioration of its surface and function. A well-finished titanium surface reduces frictional force when it comes into contact with another surface, thus preventing wear.
Improved longevity
A long service life during use is one of the many important characteristics that manufacturers pay attention to. In general, a metal part with a good surface finish is more durable and lasts longer. Polished titanium parts are more resistant to many harmful environmental influences. This ensures that the finished piece will last for many years.
Applications of polished titanium parts
Polished titanium parts are used in many manufacturing industries due to its advantages such as longer service life, corrosion resistance, etc.
aerospace industry
The aerospace industry is the main buyer of polished titanium parts because they are lightweight and have excellent strength and corrosion resistance properties.
The material is suitable for the production of aircraft engine components due to its excellent heat transfer. Examples of polished parts include fans, compressor blades, and more.
Medical industry
Dental and orthopedic manufacturers use polished titanium to create parts such as dental implants, hips, and knees. Titanium is of great importance here due to its high resistance to the effects of chemicals in food. Furthermore, it has high resistance to flexion, which reduces the risk of the dental implant breaking under strong impacts.
Additionally, titanium is very biocompatible compared to aluminum and other metals. The human body does not reject it and does not trigger an immunological reaction. Therefore, doctors use it as artificial joints for hips, knees and other joints.
Auto Industry
Polished titanium has a high strength-to-weight ratio. Its light weight helps improve fuel efficiency and reduce vehicle operating costs.
Manufacturers in the automotive industry mainly use titanium parts for the production of car exhaust systems. This is because it is a good conductor of heat, which reduces the risk of overheating. Furthermore, its rust and corrosion resistant properties increase the lifespan of the exhaust system.
Furthermore, they are used by manufacturers to produce valves, brake calipers, electric vehicle batteries and some other mechanical parts.
Naval Engineering
Titanium is the first choice for marine applications as the various titanium alloys are suitable for marine use. These alloys are robust and extremely resistant to corrosion, especially in seawater.
They can also be used in seawater desalination because they can withstand the harsh effects of chlorine. Therefore, they replace traditional copper alloy tubes in this process. Titanium parts are the basic components of many deep-sea equipment.
jewelry industry
Polished titanium parts have a unique high-gloss finish. For this reason, they are popular jewelry materials. Furthermore, its light weight and non-toxicity have contributed to its use in rings, wristwatches, etc. Additionally, they are good for sensitive skin and do not wear out easily even with frequent use.
Other titanium finish options
In addition to polishing titanium, manufacturers use the following processes to give the part the necessary surface finish.
Anodizing
Anodizing is an electrochemical process in which titanium is immersed in an electrolyte solution. The operator then directs an electrical current into the solution.
This converts the surface layer of the titanium part into titanium oxide. Furthermore, the process thickens the natural oxide layer, making it highly resistant to corrosion and long-lasting.
Note: The anodizing process may affect the thermal conductivity properties of the titanium part.
Electroplating
Electroplating involves coating the surface of the titanium part with other metals, such as nickel. This improves surface qualities and increases resistance to wear and corrosion. However, this is time-consuming and the resulting waste can pose a risk to individual health and the environment.
to brush
Various abrasive brushes are used to remove defects and process uneven titanium surfaces. The brushing process leaves a dull surface that may not be as shiny as a glass-like surface. Although brushing improves a part's appearance, it can affect its corrosion resistance. High operating costs are another disadvantage.
Powder coating
Plastics in dry powder form are applied to the titanium surface. Powder coating produces a stronger surface finish than the traditional painting process. A big advantage is that this coating does not fade easily and can withstand harsh environmental conditions. However, this powder coating process is expensive and is destroyed when it comes into contact with UV rays.
Concluding
A good surface finish is as important as the piece itself. Both the manufacturer and the end user benefit from the benefits of titanium polishing. For this reason, the process must be carried out with caution. We explain the titanium polishing process and its use in various industries. Contact us today to take advantage of our world-class parts machining services.
Common questions
Can you polish old titanium parts?
Yes, old titanium parts become new again through polishing. However, it is important to clean the piece with detergent. This will remove grease deposits that could interfere with the polishing process. However, deeper scratches may need to be touched up by a professional before polishing.
What type of sandpaper is suitable for titanium?
Generally, you can use aluminum oxide or silicon carbide sandpaper to polish. However, since titanium is a hard metal, professionals recommend aluminum oxide sandpaper of any grit.
How do I choose a buffing wheel to polish titanium?
There are different types of polishing discs, from soft to very thick. As they all have different hardness and polishing rigidity, the desired surface finish determines the polishing disc used.
