Plating Services Information
Plating services apply a thin coating of metal to the surface of a substrate in order to improve conductivity, prevent rust and corrosion, and facilitate soldering. There are two basic plating techniques: electroplating and electroless plating. Electroplating applies DC power to the plating particles so that they adhere to the substrate. Electroless plating deposits plated metal from a specialized salt solution. Some plating services perform processes that produce layers with a high hardness or abrasion resistance relative to the substrate, or compared to other coatings or finishes. Others specialize in plating layers with a soft or high purity. For example, soft gold or silver coatings are used to provide lower electrical contact resistance, an important consideration in some electrical and electronic applications. Plating services are located across the United States and around the world. Many meet International Standards Organization (ISO) requirements or automotive, aerospace, military, or OEM specifications.
Plating services often perform secondary, cleaning or parts washing activities. Burn-off or thermal cleaning systems use heat to remove grease, oil, paint or other organic compounds from the surfaces of parts. Degreasing uses a solvent or vapor to clean and remove organic compounds, as well as aqueous systems and greases that are insoluble in water. Spray washers use pressure washing or rinsing capabilities to direct a stream of water or a water/detergent mixture at high pressure to clean or remove surface debris such as scale, rust, paint, dirt, grease, or abrasive dust. In immersion tank cleaning systems or scrub tanks, parts are immersed in a tank where the cleaning bath is agitated with impellers or paddles, or the parts are scrubbed manually. Stripping and coating removal processes remove paint, coatings, or plated layers using a solvent, chemical or mechanical process. Ultrasonic cleaning processes use immersion tanks in which the cleaning solution is vibrated at ultrasonic frequencies.
Plating services often perform secondary, finishing or surface treatment activities. Blasting uses a power sprayer or tumble chamber to remove all of a metal's visible rust, mill scale, paint and contaminants. Buffing and polishing are smoothing operations that change a metal's surface appearance. Deburring rounds sharp edges or corners. Deflashing removes lines from forging, casting or molding operations. Electropolishing uses a combination of rectified current and a blended chemical electrolyte bath to remove flaws from the surface of a metal part. Honing and superfinishing are precision finishing process that generate very flat, smooth or low Ra surface finishes. Mass finishing processes are used for bulk processing. Oxygen cleaning removes combustible oils, greases or other materials that could cause an accidental fire or explosion when in contact with oxygen. Passivation removes "free iron" contamination left behind on the surface of stainless steel during machining and fabricating. Many companies perform processes that use etchants, acids, or acid pickles to chemically remove a layer of surface material or sharp edges. Sanding and grinding processes are used for rough to fine surface finishing.
Material Processing Capabilities, Certification or Quality Requirements
Plating services vary in terms of material processing capabilities and certification or quality requirements. Some companies process parts made from aluminum, copper, nickel, iron, cast iron, steel, stainless steel, and precious metals. Others process ceramics, metallized ceramics, composites, carbides, glass, plastics and polymers. Certification and quality requirements include ISO 9001:2000, ISO TS16949, AS 9100, and QS 9000. AS 9100 is a set of quality guidelines and requirements published by the Society of Automotive Engineers (SAE) in cooperation with major aerospace manufacturers. QS 9000 is a quality standard for suppliers of DaimlerChrysler Corporation, Ford Motor Company, and General Motors Corporation. Companies that meet U.S. military specifications (MIL-SPEC) and comply with OEM-specific requirements also provide plating services.