Functional Coatings / Decorative Coatings / Thin Film / Thick Film
A COATING is a covering that is applied to the surface of an object. Coatings can be in the form of THIN FILM (less than 1 micron thick) or THICK FILM (over 1 micron thick). Based on the purpose of applying the coating we can offer you DECORATIVE COATINGS and/or FUNCTIONAL COATINGS, or both. Sometimes we apply functional coatings to change the surface properties of the substrate, such as adhesion, wettability, corrosion resistance, or wear resistance. In some other cases such as in semiconductor device fabrication, we apply the functional coatings to add a completely new property such as magnetization or electrical conductivity which become an essential part of the finished product.
Our most popular FUNCTIONAL COATINGS are:
Adhesive Coatings: Examples are adhesive tape, iron-on fabric. Other functional adhesive coatings are applied to change the adhesion properties, such as non-stick PTFE coated cooking pans, primers that encourage subsequent coatings to adhere well.
Tribological Coatings: These functional coatings relate to the principles of friction, lubrication and wear. Any product where one material slides or rubs over another is affected by complex tribological interactions. Products like hip implants and other artificial prosthesis are lubricated in certain ways whereas other products are unlubricated as in high temperature sliding components where conventional lubricants can not be used. The formation of compacted oxide layers have been proven to protect against wear of such sliding mechanical parts. Tribological functional coatings have huge benefits in industry, minimizing wear of machine elements, minimizing wear and tolerance deviations in manufacturing tools such as dies and moulds, minimizing power requirements and making machinery and equipment more energy efficient.
Optical Coatings: Examples are Anti-reflective (AR) coatings, reflective coatings for mirrors, UV- absorbent coatings for protection of eyes or for increasing the life of the substrate, tinting used in some colored lighting, tinted glazing and sunglasses.
Catalytic Coatings such as applied on self-cleaning glass.
Light-Sensitive Coatings used to make products such as photographic films
Protective Coatings: Paints can be considered protecting the products besides being decorative in purpose. Hard anti-scratch coatings on plastics and other materials are one of our most widely used functional coatings to reduce scratching, improve wear resistance, …etc. Anti-corrosion coatings such as plating are also very popular. Other protective functional coatings are put on waterproof fabric and paper, antimicrobial surface coatings on surgical tools and implants.
Hydrophilic / Hydrophobic Coatings: Wetting (hydrophilic) and unwetting (hydrophobic) functional thin and thick films are important in applications where water absorption is either desired or undesired. Using advanced technology we can alter your product surfaces, to make them either easily wettable or unwettable. Typical applications are in textiles, dressings, leather boots, pharmaceutical or surgical products. Hydrophilic nature refers to a physical property of a molecule that can transiently bond with water (H2O) through hydrogen bonding. This is thermodynamically favorable, and makes these molecules soluble not only in water, but also in other polar solvents. Hydrophilic and hydrophobic molecules are also known as polar molecules and nonpolar molecules, respectively.
Magnetic Coatings: These functional coatings add magnetic properties such as is the case for magnetic floppy disks, cassettes, magnetic stripes, magnetooptic storage, inductive recording media, magnetoresist sensors, and thin-film heads on products. Magnetic thin films are sheets of magnetic material with thicknesses of a few micrometers or less, used primarily in the electronics industry. Magnetic thin films can be single-crystal, polycrystalline, amorphous, or multilayered functional coatings in the arrangement of their atoms. Both ferro- and ferrimagnetic films are used. The ferromagnetic functional coatings are usually transition-metal-based alloys. For example, permalloy is a nickel-iron alloy. The ferrimagnetic functional coatings, such as garnets or the amorphous films, contain transition metals such as iron or cobalt and rare earths and the ferrimagnetic properties are advantageous in magnetooptic applications where a low overall magnetic moment can be achieved without a significant change in the Curie temperature. Some sensor elements function on the principle of change in electrical properties, such as the electrical resistance, with a magnetic field. In semiconductor technology, the magnetoresist head used in disk storage technology functions with this principle. Very large magnetoresist signals (giant magnetoresistance) are observed in magnetic multilayers and composites containing a magnetic and nonmagnetic material.
Electrical or Electronic Coatings: These functional coatings add electrical or electronic properties such as conductivity to manufacture products such as resistors, insulation properties such as in the case of magnet wire coatings used in transformers.
DECORATIVE COATINGS: When we speak of decorative coatings the options are only limited by your imagination. Both thick and thin film type coatings have been successfully engineered and applied in the past to our customers products. Regardless of the difficulty in the geometric shape and material of the substrate and application conditions, we are always capable to formulate the chemistry, physical aspects such as exact Pantone code of color and application method for your desired decorative coatings. Complex patterns involving shapes or different colors are also possible. We can make your plastic polymer parts look metallic. We can color anodize extrusions with various patterns and it won’t even look anodized. We can mirror coat an oddly-shaped part. Furthermore decorative coatings can be formulated that will also act as functional coatings at the same time. Any of the below mentioned thin and thick film deposition techniques used for functional coatings can be deployed for decorative coatings. Here are some of our popular decorative coatings:
- PVD Thin Film Decorative Coatings
- Electroplated Decorative Coatings
- CVD and PECVD Thin Film Decorative Coatings
- Thermal Evaporation Decorative Coatings
- Roll-to-Roll Decorative Coating
- E-Beam Oxide Interference Decorative Coatings
- Ion Plating
- Cathodic Arc Evaporation for Decorative Coatings
- PVD + Photolithography, Heavy Gold Plating on PVD
- Aerosol Coatings for Glass Coloring
- Anti-tarnish Coating
- Decorative Copper-Nickel-Chrome Systems
- Decorative Powder Coating
- Decorative Painting, Custom Tailored Paint Formulations using Pigments, Fillers, Colloidal Silica Dispersant...etc.
If you contact us with your requirements for decorative coatings, we can provide you our expert opinion. We have advanced tools such as color readers, color comparators….etc. to guarantee consistent quality of your coatings.
THIN and THICK FILM COATING PROCESSES: Here are the most widely used of our techniques.
Electro-Plating / Chemical Plating (hard chromium, chemical nickel)
Electroplating is the process of plating one metal onto another by hydrolysis, for decorative purposes, corrosion prevention of a metal or other purposes. Electroplating lets us use inexpensive metals such as steel or zinc or plastics for the bulk of the product and then apply different metals on the outside in the form of a film for better appearance, protection, and for other properties desired for the product. Electroless plating, also known as chemical plating, is a non-galvanic plating method that involves several simultaneous reactions in an aqueous solution, which occur without the use of external electrical power. The reaction is accomplished when hydrogen is released by a reducing agent and oxidized, thus producing a negative charge on the surface of the part. Advantages of these thin and thick films are good corrosion resistance, low processing temperature, possibility to deposit in bore holes, slots… etc. Disadvantages are the limited selection of coating materials, relatively soft nature of the coatings, environmentally polluting treatment baths that are needed including chemicals such as cyanide, heavy metals, fluorides, oils, limited accuracy of surface replication.
Diffusion Processes (Nitriding, nitrocarburization, boronizing, phosphating, etc.)
In heat treatment furnaces, the diffused elements usually originate from gases reacting at high temperatures with the metal surfaces. This can be a pure thermal and chemical reaction as a consequence of the thermal dissociation of the gases. In some cases, diffused elements originate from solids. The advantages of these thermochemical coating processes are good corrosion resistance, good reproducibility. The disadvantages of these are being relatively soft coatings, limited selection of base material (which must be suitable for nitriding), long processing times, environmental and health hazards involved, requirement of post-treatment.
CVD (Chemical Vapor Deposition)
CVD is a chemical process used to produce high quality, high-performance, solid coatings. The process produces thin films too. In a typical CVD, the substrates are exposed to one or more volatile precursors, that react and/or decompose on the substrate surface to produce the desired thin film. Advantages of these thin & thick films are their high wear resistance, potential to economically produce thicker coatings, suitability for bore holes, slots ….etc. Disadvantages of CVD processes are their high processing temperatures, difficulty or impossibility of coatings with multiple metals (such as TiAlN), rounding of edges, use of environmentally hazardous chemicals.
PACVD / PECVD (Plasma-Assisted Chemical Vapor Deposition)
PACVD is also called PECVD standing for Plasma Enhanced CVD. Whereas in a PVD coating process the thin & thick film materials are evaporated from a solid form, in PECVD the coating results from a gas phase. Precursor gasses are cracked in the plasma to become available for the coating. Advantages of this thin and thick film deposition technique is that significantly lower process temperatures are possible as compared to CVD, precise coatings are deposited. Disadvantages of PACVD are that it has only limited suitability for bore holes, slots etc.
PVD (Physical Vapor Deposition)
PVD processes are a variety of purely physical vacuum deposition methods used to deposit thin films by the condensation of a vaporized form of the desired film material onto workpiece surfaces. Sputtering and evaporative coatings are examples of PVD. Advantages are that no environmentally damaging materials and emissions are produced, a large variety of coatings can be produced, coating temperatures are below the final heat treatment temperature of most steels, precisely reproducible thin coatings, high wear resistance, low frictional coefficient. Disadvantages are bore holes, slots ...etc. can only be coated down to a depth equal to the diameter or width of the opening, corrosion resistant only under certain conditions, and for obtaining uniform film thicknesses, parts must be rotated during deposition.
The adhesion of functional and decorative coatings are substrate dependent. Furthermore, the lifetime of thin and thick film coatings depends on environmental parameters such as humidity, temperature...etc. Therefore, before considering a functional or decorative coating, contact us for our opinion. We can choose the most suitable coating materials and coating technique that fits your substrates and application and deposit them under the strictest quality standards. Contact AGS-TECH Inc. for details of thin and thick film deposition capabilities. Do you need design assistance ? Do you need prototypes ? Do you need mass manufacturing ? We are here to help you.