What is Dezincification
Dezincification is a corrosive process that occurs in copper-zinc alloys, commonly known as brass, where zinc is selectively removed from the alloy, leaving behind a porous structure that is rich in copper but lacks mechanical strength. This phenomenon is a form of dealloying, where one of the constituents of an alloy, in this case, zinc, is preferentially corroded and leached out.
Dezincification typically takes place when copper-zinc alloys containing more than 15% zinc are exposed to specific water compositions and service conditions. Factors that contribute to dezincification include slightly acidic or alkaline water, low rates of flow, high tube-wall temperatures, and the presence of permeable deposits or coatings on the surface.
The effects of dezincification can manifest in various ways. One common indication is the appearance of dull red spots on the surface of brass, which are a result of the zinc being leached out, leaving behind a copper-rich surface. Another manifestation is the seepage of water through fittings or leakage at valves. In severe cases, dezincification can lead to actual breakage, with the fractured surface exhibiting a dull coppery appearance.
Note that not all copper alloys are susceptible to dezincification. Copper alloys with less than 15% zinc content, as well as alpha brasses inhibited by arsenic or antimony, are generally resistant to dezincification when exposed to water or soil environments during service.
To prevent dezincification, it is recommended to specify brass alloys with low zinc content or proven dezincification-resistant yellow brass alloys. Manufacturers should provide alloy compositions or chemistry for the materials used in valves and fittings to ensure their resistance to dezincification. By considering these factors, the risk of dezincification can be minimized, ensuring the integrity and longevity of copper-zinc alloy components in PCB applications.
Frequently Asked Questions
What Is the Process of Dezincification
1988). The process of Dezincification involves the dissolution of zinc from brass, resulting in the deposition of copper on the metal surface and the formation of copper crystals. This rearrangement occurs due to the attraction between the copper on the surface and negative ions in the solution.
What Are Types of Dezincification
There are two types of dezincification: plug-type or uniform. Plug-type dezincification is a localized form that has minimal or no impact on the surrounding area. It is important to be cautious of plug-type dezincification when dealing with neutral or alkaline water that has a high salt content and is above room temperature.
What Is Dezincification Resistant
DZR (Dezincification Resistant) or DR Brass is a specific type of brass that is utilized in manufacturing processes due to its ability to resist dezincification corrosion. Products that possess Dezincification Resistant properties are typically labeled with the “DR” mark. Brass, a commonly used metal alloy composed of copper and zinc, is the primary material used in the production of DZR or DR Brass.
What Is the Difference Between Brass and DZR
DZR, also known as dezincification-resistant brass, is a unique copper alloy that has been specifically engineered to have superior corrosion resistance compared to regular brass. It has a higher zinc content than standard brass and is capable of withstanding more severe environments without experiencing corrosion or developing pinholes on its surface.
What Is Meant by Dezincification and How Do You Avoid It
Dezincification refers to the selective removal of zinc from an alloy, resulting in a porous structure that is rich in copper and lacks mechanical strength. The manifestation of dezincification can vary depending on the composition of the water and the conditions it is exposed to. To prevent dezincification, certain measures can be taken.
Which Metal Alloy Can Be Attacked by a Type of Corrosion Called Dezincification
A specific type of corrosion known as Dezincification can attack a metal alloy. This corrosion process involves the preferential attack and replacement of the less noble metal in the alloy’s matrix by cathodic products. Dezincification commonly occurs with brass, where the zinc in the alloy is attacked, leaving copper behind.
What Is the Process of Coating of Zn
The process of applying a layer of zinc onto iron is referred to as Galvanization.