What Is Manganese Phosphate and What Is It Used For?

Metal finishing is important for a variety of reasons, notably as it pertains to enhancing part performance. This may include minimizing the wear and tear of metallic products, improving electric conductivity, providing enhanced resistance, and more. One of the most popular types of metal finishes is manganese phosphate, particularly for steel parts that operate in demanding applications.

Read on for a closer look at manganese phosphate, its benefits, and how coated parts are utilized throughout various industries.

Manganese Phosphate 101

So, what is manganese phosphate, and how and why is it used? Simply put, manganese iron phosphate is a type of conversion coating. This coating is produced by subjecting the part to a chemical process that changes the surface of the part. When applied to a steel part, it creates a heavy crystalline finish on the surface. This coating is insoluble, meaning that it can't be dissolved by another material, thus increasing the part's strength and wear resistance.

• Automotive and aerospace
• Defense and weapons
• Marine equipment
• Electronics and commercial

This type of metal finishing is most commonly used within engines, transmission systems, and gears to provide smoother overall operation while increasing the service life of treated components. However, it can also be applied to various other metal products for added performance, such as washers, magnet cores, nuts and bolts, and more.

The Coating Process

Wondering how to apply a manganese phosphate solution? One option is to clean the part followed by immersion in a mineral acid with thorough rinsing after each step. A second option, and what we do at Light Metals Coloring, is to clean and then sandblast the surface as a preparation for coating. The manganese iron phosphate coating is then applied to exposed surfaces.

During the finishing process, the part will be immersed in the manganese phosphate solution for up to 15 minutes at a high temperature of over 200 degrees Fahrenheit. The crystalline structure formed can be modified based for your performance requirements.

Benefits of Manganese Iron Phosphate

Compared to other phosphate coatings, manganese phosphate offers a variety of valuable benefits that can improve the overall performance and reliability of metal parts. These include:

• Maximum Hardness – Manganese phosphate is the hardest type of phosphate coating available, providing unbeatable durability and protection.
• Increased Corrosion Resistance – Because manganese phosphate is insoluble, it can't be broken down by water, acids, or other liquids.
• Improved Lubrication – The crystalline finish absorbs oil and other lubricants, making it ideal for metal parts designed to come in contact with other metal parts, like engines and transmissions. The wear of phosphated parts in friction is dramatically reduced.
• Excellent Adhesion – Manganese phosphate provides a crystalline structure that is an effective base for secondary coatings and paint.

Light Metals Coloring: Leaders in Manganese Phosphating and More

Light Metals Coloring is an industry-leading provider of metal finishing solutions throughout a variety of end markets and industries. If you have a project that requires a phosphate coating, we'll carefully assess your part to help determine the best option for the performance you require.

For more information about the different types of metal finishing services or more on the Manganese Phosphate coatings we provide, contact the Light Metals Coloring team today!

Manganese Phosphating FAQ

What are the benefits of manganese phosphate coatings?

Manganese phosphate coatings offer several benefits, including:

• Enhanced wear resistance
• Improved corrosion protection
• Better lubricant retention, which reduces friction
• Increased surface hardness
• Reduced galling and seizing during assembly processes

What metals can be treated with manganese phosphate?

Manganese phosphate can be applied to various ferrous metals, including steel and cast iron. It is not suitable for non-ferrous metals like aluminum, copper, or their alloys.

How should manganese phosphate-coated parts be maintained?

To maintain the effectiveness of manganese phosphate-coated parts, it is essential to:

• Regularly apply and replenish lubricants as needed
• Store parts in a dry environment to prevent moisture-related corrosion
• Inspect and clean parts periodically to remove any debris or contaminants