Metal finishing is the last step in the deep draw process and often essential. Production doesn’t always end after stamping. Most metal forming manufacturers offer some type of metal finishing, also known as secondary operations.
Through a dedicated supply chain we can provide you with many valuable post-deep draw stamping solutions for your part. We select our supply chain based on ISO 9001:2015 certification along with other essential criteria.
Advantages of metal finishing treatments include:
- Corrosion resistance, chemical change, and wear
- Enhanced strength
- Greater durability
- Improved appearance
- Electrical conductivity
7 Types of Metal Finishing Used Frequently after Deep Draw Stamping
1. Cleaning
- Ultrasonic precision cleaning uses high frequency, high intensity sound waves transmitted through a liquid to scrub the surface clean of submersed parts. Contaminants such as dust, dirt, fibers, grease, oil and other microscopic impurities are removed to achieve a high level of cleanliness.
- Aqueous cleaning is a process that uses water-based solutions to remove lube oil, water-soluble oil, silicone grease, dust, fingerprints, and loose burrs. Aqueous cleaning has replaced other cleaning methods using solvents as it is more environmentally safe.
- Vapor Degreasing is a surface cleaning process that uses solvent vapors to wash oils and other contaminants off metal and plastic parts. It involves solvents in vapor form to cleanse the parts and those containing deep recesses that are difficult to reach.
- Passivation improves the corrosion resistance properties of stainless steels. A solution of nitric or citric acid is used to dissolve iron and other contaminants embedded in the surface during the metal forming process that can cause corrosion. Advantages include improved corrosion resistance, uniform, smooth appearance and finish and cleanliness.
- Other metal cleaning methods include de-scaling, rust removal, and rust prevention.
2. Mass Finishing
- Vibratory deburring is a process used to deburr, descale, burnish, clean and brighten small parts in batches. Specifically paired pellets of media combined with the batch of parts are paced into the tub of a vibratory tumbler. The tub of parts mixed with the media then vibrates which causes the media to rub against the parts until a desired surface finish is achieved. This can be a wet or dry process.
- The tumbling process, also known as barrel finishing or barrel tumbling, improves the surface of a part by rotating a batch of parts combined with media and compounds in a specially designed barrel, creating friction as the parts tumble against each other and the media.
- Ball Burnishing is a method of metal finishing like vibratory finishing where steel media balls scour against the parts to achieve a high luster finish.
3. Superfinishing
Superfinishing is a metal working process that improves the surface finish of a workpiece. Like other metal finishing processes, it involves the removal of material. Superfinishing is typically performed after other metal finishing processes have been completed. Superfinishing is achieved through a multi-step, chemically accelerated vibratory process. The technology removes microscopic peaks that remain after the manufacturing process creating a uniform, high luster finish.
4. Electropolishing
Electropolishing is an electrochemical and reverse plating process that removes the outer layer on a metal part to address microscopic imperfections within it’s finish. The electropolishing process serves to polish, passivate, or deburr metal parts. Electropolishing is essentially the opposite of electroplating; through the application of an electrical current to the surface, a thin layer is removed and along with it, any impurities that may have contaminated the surface.
5. Plating
Plating is the process of coating and protecting metals by layering a thin metal over another parent metal. It is an essential post metal forming process as the plating can protect against corrosion, improve solderability, harden the component, reduce friction, and alter conductivity. Materials used for plating include gold, silver, copper, tin, zinc and nickel.
Selecting the best metal plating process depends on the material and the type of stamped metal and such processes include:
- Reel to reel plating
- Barrel plating
- Rack plating
- Zinc/ zinc-nickel electroplating
- Aluminum chromating
- E-coat
6. Black Oxide
Black oxide is chemical conversion process used to blacken the surface of a part without adding a thick coating. A chemical conversion process uses a chemical solution to force a reaction on the surface of the part rather than a plating or a coating process which ads a thick layer on top of the base material. Black oxide is typically done on ferrous metals (metal containing iron).
7. Heat Treating
Heat treating is a general term for many different thermal processes used on various metals. These processes are used to enhance or modify the properties of the metal to meet the requirements of the intended application.
The most common methods for heat treating include:
- Annealing
- Case hardening
- Precipitation hardening
- Stress relieving
- Quenching and tempering
Read more in our recent blog: “Heat Treating Benefits for Your Manufactured Part.”
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