Since its initial development in the 1980s, 3D printing has been gaining momentum in the manufacturing industry. Instead of subtracting from a block of raw material or injecting into a mold, a part is created by building the structure layer by layer using a computer file as the “recipe” and raw material typically in the form of a powder, resin, or synthetic filament.
While 3D printing is praised for its ability to create geometric shapes and accommodate design changes with greater ease than traditional manufacturing, there are material restraints that must be considered. The lightweight plastics and resins used are susceptible to damage or delamination under certain stresses and do not conduct electricity.
Electroplating and Metalizing 3D-Printed Parts
Parts can be 3D printed using metal coatings to avoid some of the above-mentioned pitfalls. However, this option is relatively expensive and not yet considered practical for large scale production. Continuing to 3D print with plastic material keeps the part lighter than the metal equivalents. Maintaining a lightweight product is notably important in the aerospace and automotive industries as they strive to maintain fuel-efficiency in a time when fuel costs and usage are on many minds. How can these 3D-printed parts be utilized on a larger scale unless they maintain a crucial strength and corrosion resistance?
Plating on 3D plastic couples additive manufacturing and metal plating; resulting in a final product that is lightweight and functional. The layer of metal deposited onto the 3D print provides the corrosion resistance, strength, and electrical conductivity necessary to allow the part to be treated like a traditionally manufactured part without the material waste or extra weight.
What 3D-Printed Materials can be Metalized and Electroplated?
With so many options for print material, it wouldn’t be practical to list them. There are a few properties that can improve your ability to metalize the polymer.
- Chemical Resistance: Plating processes use acids and salts that can cause chemical reactions with some materials. This can contaminate the plating solutions requiring costly repairs.
- Porosity: The more you can fill your 3D print, the better chance you have in plating the material. The part will travel through several plating baths and a variety of chemistry. Each one needs to be effectively cleaned off the part before traveling to the next step. If the material traps solution, it will leach out in a subsequent step while decreasing the integrity of the deposit.
- Heat Resistance: Some chemical plating baths are heated. This requires the material to be able withstand a minimum of 200F without deformation.
- Glass or Mineral Reinforcement: Although not required, a 10% to 40% reinforcement has been proven to increase adhesion.
Learn More about plating on plastics and composites.
Properties Added by Electroplating 3D-Printed Parts
Most subtractive or injection molding parts require a final coating or treatment of some kind to protect the substrate from corrosion and improve longevity within the final application. By applying this necessity to 3D prints, manufacturers have more flexibility in creating large and small batches of a variety of designs without the need to invest in new, expensive equipment and hours of calibration. Applying plating on plastic parts increases the mechanical properties by protecting the substrate, adding conductivity, and strengthening the part overall.
- Strength: Resin used in 3D printers tend to be brittle and break easily. Adding a layer of metal to a 3D printed part will increase the ultimate tensile strength of the part.
- Conductivity: Plastics are insulators and metals are conductors. Adding metal plating to plastic, even selectively, allows the part to become electrically conductive. This added conductivity to plastic is very useful in the electric vehicle market and can be utilized in plating plastic connectors.
- Wear Protection: Depending on the thickness, a metal coating on 3D printed parts can have long-term wearability and corrosion resistance against external elements. Metals like gold and electroless nickel have very good abrasion resistance. Keep in mind that the thicker the plating, the heavier the part will become.
- Cosmetics: This is typically not what we focus on here at INCERTEC, but plating can be used to improve the appearance or be used as an identifier to a printed part.
- Electromagnetic Shielding: Plating is used to reduce or eliminate electromagnetic interference (EMI) or radio frequency interference (RFI) in the electronics industry.
Types of Metal Best Used With 3D Prints
Virtually any finish can be applied to a plastic substrate once it has been metalized.
- Gold – A noble metal when under normal conditions, does not oxidize or react chemically. Gold plating is frequently used in electronic and connector applications due to its oxidation resistance and durability.
- Electroless Copper – Typically used as a base layer on plastic substrates, electroless copper is conductive, ductile and deposits in a uniform layer over the substrate.
- Electroless Nickel – A co-deposit of nickel and phosphorus that mirrors the surface finish of the substrate with a Rockwell C hardness ranging from 41-51 when plated at a high or mid phosphorus co-deposit. Electroless nickel plating for 3D printed parts creates a uniform deposit onto the substrate since it is not dependent on an external DC current.
- Silver – A white luster semi-precious metal that boasts the highest thermal and electrical conductivity of all metals available in matte, bright, and semi-bright. Silver also has excellent solderability and lubricity.
When electroplating 3D prints, tin, cadmium and zinc-nickel are also suitable finishes to add to a plastic substrate. Contact us for a quote or to learn more.
INCERTEC Plastic Plating Services
INCERTEC handles a wide variety of plating on plastic as well as plating on other unique substrates like composites, magnets, and ceramics. Contact us to discuss your plastic plating needs.