Electroplating on Composite Material

Plating Onto Composite Material

A composite material is made of two or more distinct constituent materials. Though the constituent ingredients remain distinct within the composite, the final product material has new properties — such as greater strength or heat resistance — as a result of the combination.

Generally, composite materials are formed by adding a reinforcement component to a matrix material, like mixing gravel with cement to create the stronger material concrete. Indeed, building materials such as concrete and plywood are familiar examples of composites.

Some composites are more carefully structured than concrete, however. Engineers often weave small reinforcement fibers into a matrix, using intentional patterns to increase the material's performance in various capacities. The matrix holds the reinforcement fibers in place, and the reinforcement provides improved properties to the matrix, preventing breaking or bending, for example.

Composites are popular for industrial applications because the wide variety of available components make composites easily customized to fit an industry or product's unique physical requirements. A composite material can be lighter, stronger, more durable or even less expensive than a single homogeneous material.

Which Composites Can You Use for Plating?

Given the many industrial applications for composite materials, it's no wonder that metal-plated composites are popular as well. It's possible to plate onto metal composites in much the same way that you plate onto a pure metal base. In addition, experts like SPC can plate onto non-metal composites. Let's take a look at the three main types of composite materials people frequently coat with metal:

1. Metal matrix composites (MMCs): Metal matrix composites are composed of a metal matrix and another metal or other reinforcement material. It's possible to plate onto MMCs using a standard electroplating process, as long the composite conducts an adequate electrical charge within the bath to instigate the plating process.
2. Ceramic matrix composites (CMCs): CMCs are composed of a ceramic matrix reinforced with ceramic fibers. The components can be any ceramic materials, including carbon and carbon fibers, though these are technically not "ceramics." For someone to plate onto ceramics, the base first needs to undergo an electroless plating process in order to conduct electricity. Usually, the ceramic base will receive a thin coating of electroless nickel before it's ready for normal electroplating.
3. Fiber-reinforced plastic (FRP): FRP is a composite made by using fibers to reinforce a plastic matrix. The reinforcing fibers commonly found in FRP include carbon or glass, as in fiberglass. Like ceramics, plastic composites can be plated by adding a thin layer of metal before submersion for electroplating, though some research suggests that carbon-reinforced plastics may partially respond to electroplating without this step.

In addition to metal, ceramic and plastic composites, some industries, including the aerospace and military sectors, may use advanced composite materials. They tend to have comparatively strong reinforcement fibers and weaker matrices. The specific material will determine the method necessary for metal finishing.

Benefits of Plating onto Composite Material

People choose to plate onto composite materials for a number of reasons. Sometimes a composite material is substituted for a solid metal base in order to save money. After all, it's a lot less expensive to give a strong plastic a silver coating than to use solid silver. For consumer products, a metal finish on plastic serves a similar aesthetic function at a much lower cost.

Many industries also employ composite materials due to their high-performance properties. Ceramic composites are stronger than normal ceramics and can withstand high temperatures, making them ideal for components that must endure heat, like heat shields on spacecraft or circuit-board components in electronics. With a metal coating, these materials gain other enhanced properties, like electrical conductivity.

Plastic composite materials are used to ensure efficiency as well as performance. In the 1970s, the American automotive industry used metal-coated plastic materials to reduce the weight of their cars and improve gas mileage. Plating on plastic composites helps companies gain the benefits of metal without adding unnecessary weight.

Engineers also benefit from the ability to design their own ideal composite. By combining reinforcements and matrices with different properties, a clever designer can create a material that serves its purpose better than any other existing material. Sometimes, all that's needed to complete this product is a smooth metal surface.

At SPC, we have experience working with all kinds of materials. We can plate onto metal, plastic and ceramic composite materials for a wide range of industries, including automotive and electronics. We apply our nine decades of metal finishing experience to every project we take on, whether they involve common base materials or specialized composites. Contact SPC today to learn more about our process.

Additional Resources:

• Challenges of Plating Onto Ceramics
• Benefits of Ceramic Plating
• Plating on Exotic Refractory Metals
• Applications of Plating Glass Biotechnology