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| Buffing |
Instead of using 'elbow grease' you will be using the power and speed of an electric motor. The edge, or face, of the wheel is the 'sanding block', which carries a thin layer of 'compound' which is the sandpaper. Varying types of wheel are available, and the different grades of compound are scaled similar to sandpaper. The compounds are made from a wax substance which has the different abrasive powders added to it. When this hard block is applied to the edge of a spinning buffing wheel, the heat from the friction melts the wax, and both wax and abrasive are applied in a thin slick to the face of the wheel.
Purpose Of Buffing
Polishing and buffing are finishing processes for smoothing a work piece's surface using an abrasive and a work wheel. Technically polishing refers to processes that use an abrasive that is glued to the work wheel, while buffing uses a loose abrasive applied to the work wheel. Polishing is a more aggressive process while buffing is less harsh, which leads to a smoother, brighter finish. A common misconception is that a polished surface has a mirror bright finish, however most mirror bright finishes are actually buffed.
The removal of oxidization (tarnish) from metal objects is accomplished using a metal polish or tarnish remover; this is also called polishing. To prevent further unwanted oxidization, polished metal surfaces may be coated with wax, oil, or lacquer. This is of particular concern for copper alloy products such as brass and bronze.
The term chem-mechanical was coined to describe action of corrosive slurry on silicon in a polishing process. Multiple rotating heads, each studded with silicon wafers, get forced against a large rotating buffing pad, which is bathed in corrosive slurry. Material removal at elevated temperature progresses first through oxidation, then through oxide removal by abrasion. This cycle repeats with each rotation of a head. Potassium Hydroxide and Silox (white paint-base) can be combined with deionized water to form such a slurry.
When To Use Buffing
Polishing is often used to enhance the looks of an item, prevent contamination of instruments, remove oxidation, create a reflective surface, or prevent corrosion in pipes Inmetallography and metallurgy, polishing is used to create a flat, defect-free surface for examination of a metal's microstructure under a microscope. Silicon-based polishing pads or a diamond solution can be used in thepolishing process.
Process
The condition of the "metal" at hand determines what type of abrasive will be applied. The first stage, if the material is unfinished, starts with a rough abrasive (perhaps 60 or 80 grit) and each subsequent stage uses a finer abrasive, such as 120, 180, 220/240, 320, 400 and higher grit abrasives, until the desired finish is achieved. The rough (i.e. large grit) passes remove imperfections within the metal surface like pits, nicks, lines and scratches. The finer abrasives leave progressively finer lines that are not visible to the naked eye. To achieve a #8 Finish (Mirror) it requires polishing and buffingcompounds, polishing wheels and high speed polishing machines or other machine tools that can be used for polishing, like an electrical drill. Lubricants like wax and kerosene may be used as lubricating and cooling media during these operations, although some polishing materials are specifically designed to be used "dry." Buffing may be done by hand with a stationary polisher or die grinder, or it may be automated using specialized equipment
When buffing there are two types of buffing motions: the cut motion and the color motion. The cut motion is designed to give a uniform, smooth, semi-bright surface finish. This is achieved by moving the workpiece against the rotation of the buffing wheel, while using medium to hard pressure. The color motion gives a clean, bright, shiny surface finish. This is achieved by moving the workpiece with the rotation of the buffing wheel, while using medium to light pressure.
When polishing brass,(A softer metal) there are often minute marks in the metal caused by impurities. To smooth out the finer marks, the surface is polished with a very fine (600) grit, copper plated, then buffed to a mirror finish with an airflow mop.
Polishing operations for items such as chisels, hammers, screwdrivers, wrenches, etc., are given a fine finish but not plated. In order to achieve this finish four operations are required: roughing, dry fining, greasing, and coloring. Note that roughing is usually done on a solid grinding wheel and for an extra fine polish the greasing operation may be broken up into two operations: rough greasing and fine greasing. However, for inexpensive items money is saved by only performing the first two operations.
Polishing knives and cutlery is known as fine glazing or blue glazing. Sand buffing, when used on German silver, white metal, etc., is technically a buffing operation because it uses a loose abrasive, but removes a significant amount of material, like polishing.
Equipment
Aluminium oxide abrasives are used on high tensile strength metals, such as carbon and alloy steel, tough iron, and nonferrous alloys. Silicon carbide abrasives are used on hard and brittle substances, such as grey iron and cemented carbide, and low tensile strength metals, such as brass, aluminium, and copper.
Polishing wheels come in a wide variety of types to fulfill a wide range of needs. The most common materials used for polishing wheels are wood, leather, canvas, cotton cloth, plastic, felt, paper, sheepskin, impregnated rubber, canvas composition, and wool; leather and canvas are the most common. Wooden wheels have emery or other abrasives glued onto them and are used to polish flat surfaces and maintained good edges. There are many types of cloth wheels. Cloth wheels that are cemented together are very hard and used for rough work, whereas other cloth wheels that are sewn and glued together are not as aggressive. There are cloth wheels that are not glued or cemented, instead these are sewed and have metal side plates for support. Solid felt wheels are popular for fine finishes. Hard roughing wheels can be made by cementing together strawboard paper disks. Softer paper wheels are made from felt paper. Most wheels are run at approximately 7500 surface feet per minute (SFM), however muslin, felt and leather wheels are usually run at 4000 SFM.
Buffing wheels, also known as mops, are either made from cotton or wool cloth and come bleached or unbleached. Specific types include: sisal, spiral sewn, loose cotton, canton flannel, domet flannel, denim, treated spiral sewn, cushion, treated vented, untreated vented, string buff, finger buff, sisal rope, mushroom, facer, tampered, scrubbing mushroom, hourglass buff, rag, "B", climax, swansdown, airflow, coolair, and bullet
The following chart will help in deciding which wheels and compounds to use when polishing different materials. This chart is a starting point and experienced polishers may vary the materials used to suit different applications.
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| Nickel Chrome Plating |
Nickel-Chrome plating is used in applications where corrosion resistance is desirable and when plating intricate surfaces or small or deep bores, for a uniform thickness and medium to high hardness. The process is limited to certain types of metals and it requires a strict, high level of quality control.
Purpose Of Plating
Perhaps the most common decorative metal plating technique is nickel-chrome plating. Master Finish Company specializes in this finishing process, in which a thin layer of chrome is applied over a layer or multiple layers of nickel plating.
For most exterior components requiring corrosion protection and wear, a bright nickel layer is plated over semi-bright nickel plating, and then covered with a thin application of chrome plating. This provides a hard, decorative chrome finish that can withstand the elements, and is very popular for parts that are exposed to the elements, such as in automobiles and motorcycles.
When To Use Nickel Chrome Plating
Nickel-chrome plating can be used in the as-deposited condition or may be hardened, depending on the intended service conditions.
- Corrosion-Resistant : Specifically, the nickel plating process deposits a 12-15 percent nickel coating on the metals. This nickel plate resists corrosion, even at prolonged temperatures of 250 degrees Fahrenheit. nickel plate is reliable and uniform for use in electrical circuits. When sprayed with saltwater, nickel plate lasts 360 hours before the surface is corroded to a white appearance and 1,000+ hours before it rusts red.
- Durable, Scratch-Resistant
- Malleable and Polishes Well : Nickel is a shiny silver-white metal with a slightly gold tint. It is malleable and polishes well. Malleable nickel makes the surface of metal flexible for the creation of decorations, sculptures, and craft projects. it is not flammable and deposits do not easily form on its surface. Nickel-Chrome plated metal makes pipes for use in industrial and household plumbing.
- Conducts Heat and Electricity : Nickel-Chrome conducts heat and electricity When bound to metal, nickel-chrome plated is used by all the major automobile anufacturers to produce sturdy, scratch-resistant, heat-resistant cars and trucks. Nickel-chrome plated iron is used to create batteries with a long shelf-life and that conduct and store electricity longer and do not degrade after long hours of use. Nickel-chrome plated is also less expensive than other alloys.
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| Hard Chrome Plating |
Hard-Chrome plating is used in applications where corrosion resistance is desirable and when plating intricate surfaces or small or deep bores, for a uniform thickness and medium to high hardness. The process is limited to certain types of metals and it requires a strict, high level of quality control.
Purpose Of Plating
Chrome plating is the process by which chromium ions dissolved in water are electrochemically transformed into chromium metal atoms and deposited uniformly across a conductive metal surface. There are two general types of chrome plating: hard and decorative. Hard chrome plating applies a thicker, dull layer of chromium metal on top of industrial parts such as hydraulic cylinders, gun bores and rollers. These parts are made of hardened steel which, despite its strength, is poor at oil retention and other wear-resistant properties. Adding a layer of oil-retaining chromium solves these problems.
Decorative chrome plating is the type consumers are probably more familiar with: brilliant, smooth and highly-reflective
Why Hard Chrome Plating ?
Chromium is a hard metal with a fine grain structure. This makes it ideal for protecting the engraved copper deposits applied to metals During press runs of any length hard chromium protects the metals from wear caused by paper and grit abrasion and, under normal conditions, enables the metals to print in clearer, sharper lines for the entire run.
Chromium plated metals also have greater corrosion resistance which protects the metal during storage and permits it to be put back into service quickly with minimum of preparation. Without the abrasion protection of hard chromium, metals wear quickly and the printing soon becomes distorted. Properly applied chromium deposits protect the engraving and extend its reproduction fidelity through several press runs.
This is possible because the normally poor micro throwing power of chromium plating baths enables them to reproduce the copper substrate surface exactly. Thus the engraving lines and patterns remain sharp and clear. This differs from plating solutions with good micro throwing power, such as bright nickel, which would tend to fill in the engraved lines. For this reason, special care must be taken to polish metals before hard chromium plating since the chromium bath will also reproduce any undesirable surface imperfections in the copper plating such as nicks and scratches.
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| Electroless Nickel Plating |
Electroless nickel plating is used in applications where corrosion resistance is desirable and when plating intricate surfaces or small or deep bores, for a uniform thickness and medium to high hardness. The process is limited to certain types of metals and it requires a strict, high level of quality control.
Electroless nickel plating is an auto-catalytic reaction used to deposit a coating of nickel on a substrate. Unlike electroplating, it is not necessary to pass an electric current through the solution to form a deposit. This plating technique is to prevent corrosion and wear. EN techniques can also be used to manufacture composite coatings by suspending powder in the bath. Electroless nickel plating has several advantages versus electroplating. Free from flux-density and power supply issues, it provides an even deposit regardless of workpiece geometry, and with the proper pre-plate catalyst, can deposit on non-conductive surfaces.
Electroless coating (also known as autocatalytic coating) is defined as the deposition of a metallic coating by a controlled chemical reduction that is catalyzed by the metal or alloy being deposited.
By far the most common form of electroless coating is nickel plating, which is actually a nickel-phosphorus alloy (2-10% P). Electroless nickel has the unusual quality of being amorphous and not crystalline in structure. These coatings possess high hardness, natural lubricity, and good wear and abrasion resistance.
Electroless nickel plating (EN) is an auto-catalytic chemical technique used to deposit a layer of nickel-phosphorus or nickel-boron alloy on a solid workpiece, such as metal or plastic. The process relies on the presence of a reducing agent, for example hydrated sodium hypophosphite (NaPO2H2•H2O) which reacts with the metal ions to deposit metal. The alloys with different percentage of phosphorus, ranging from 2-5 (low phosphorus) to up to 11-14 (high phosphorus) are possible. The metallurgical properties of alloys depend on the percentage of phosphorus.
Electroless nickel is sometimes an economical treatment to improve the performance of carbon steel in mildly corrosive environments (such as chlorides, trace acids, caustic solutions) and in situations where light wear may occur in service. It is, however, difficult to deposit electroless nickel on chromium-containing steels. Electroless nickel can be deposited on the internal diameter of tubular components and other difficult to access surfaces.
There are variants of electroless nickel plating, the most common of which include:
- composite electroless nickel, in which SiC (silicon carbide) particles are co-deposited with the nickel to enhance its strength and wear resistance
- duplex electroless nickel where an undercoat containing 14% phosphorus is used with a top coat of 5% phosphorus.
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| Silver Plating |
Advanced Plating Technologies offers functional silver plating services to QQ-S-365 ASTM B700 and AMS 2410, AMS 2411 & AMS 2412. Our expertise in providing precision barrel, rack and vibratorysilver plating services is currently employed in numerous industries including the medical, telecommunications, aerospace and electronics industries. Heavy build silver plating services up to 0.025” per side have been successfully provided by APT within the petrochemical and bearing industries.
APT offers a wide range of silver plating services including matte, semi-bright and bright silver deposits. Purities up to 99.9% pure are available with Type I, matte, 99.9% pure silver plating services available for wire bonding or defense applications. APT has the ability to underplate with variousnickel plating services including both bright electrolytic nickel, sulfamate electrolytic nickel and electroless nickel deposits as well as copper plating if required.
Inhibiting of silver plating services with RoHS compliant post plate chromates and triazoles are available. In addition, nitrogen backfilled and sealed packaging is available to eliminate the potential for tarnishing of uninhibited deposits. Nitrogen bagging can extend the shelf life of silver plated products indefinitely ensuring low contact resistance and solderability at time of assembly when the packaging is opened.
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| Copper Plating |
Our company is engaged in manufacturing and exporting of a wide range of Copper Plating Services, which adds durability and strength to the materials. These are catering to the requirements of diverse industries such as architectural, auto, camping and hunting and collars/coupling industry. Our services are renowned for fine finishing, non-uniformity and extra shine.
Copper plating is the process of coating of a material with copper by an electrolytic process, to reduce corrosion. There are three types of processes: acid, alkaline non-cyanide, and cyanide.Copper plating is the process in which a layer of copper is deposited on the item to be plated by using an electric current.
Three basic types of processes are commercially available based upon the complexing system utilized:
- alkaline-(several modifications of cyanide and non-cyanide) complexed bath
- acid-(sulfate and fluoborate) complexed bath
- mildly alkaline-(pyro phosphate) complexed bath
With a higher current, hydrogen bubbles will form on the item to be plated, leaving surface imperfections. Often various other chemicals are added to improve plating uniformity and brightness. Without some form of additive, it is almost impossible to obtain a smooth plated surface. These additives can be anything from dish soap to proprietary compounds.
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| Electropolishing |
Our company is offering a wide range of Electropolishing Services, which is a process in which, metal is uniformly removed from the surface, resulting the development of flat as well as bright surface finish. High quality acids and appropriate electrical current are applied on the surface to ensure the enhancement of the surface of components. In order to meet the different requirements of our clients, we offer electropolishing solution in various finishes.
Electropolishing is a process by which metal is removed from a work piece by passage of electric current while the work is submerged in a specially-designed solution. The process is essentially the reverse of electroplating. In a plating system, metal ions are deposited from the solution onto the work piece; in an electropolishing system, the work piece itself is dissolved, adding metal ions to the solution.
Advantages Of Electropolishing
- Brightening
- Burr removal
- Total passivation
- Oxide and tarnish removal
- Reduction in surface profile
- Removal of surface occlusions
- corrosion resistance
- Increased ratio of chromium to iron
- Improved adhesion in subsequent plating
- Reduced buffing and grinding costs
- Removal of directional lines
- Radiusing of sharp edges
- Reduced surface friction
- Stress relieved surface
- Removal of hydrogen
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| Glass Bead Blasting |
Bead blasting is the process of removing surface deposits by applying fine glass beads at a high pressure without damaging the surface. It is used to clean calcium deposits from pool tiles or any other surfaces, and removes embedded fungus and brighten grout color. It is also used in auto body work to remove paint.
Glass Beads are solid glass spheres. They should not be confused with costume jewellery having a hole. They are manufactured from high grade soda-lime silica glass containing SiO2 around 70%. They are free from free lead, iron and silica. They are manufactured from colourless glass for most of their uses.
Glass bead blasting is a metal cleaning process that creates a clean, bright, uniform matte texture. The glass beads are applied to a surface using low air pressure. This process removes paint, rust and corrosion from all types of metals, from autos, trucks, equipment, machinery engine blocks, heads and intakes. Using the bead blasting process a surface can be cleaned without any damage. The beads come in a variety of sizes. The smaller the glass beads, the smoother the surface, larger beads produce a more textured finish.
Is Glass Bead Blasting safe for the environment?
Bead blasting is chemically inert and environmentally friendly. This method of metal cleaning is an acceptable method whenproperly controlled. The glass beads used in this process are made from lead-free, soda like type glass, containing no free silica that is made into preformed ball shapes. The glass beads can be recycled approximately 30 times.
Benefits
Glass bead blasting is an effective process used in automotive restoration. Bead blasting produces a much smoother and brighter finish than angular abrasives. There is no dimensional change to the metal surface. Glass bead blasting leaves no embedded contaminates or residue. This process smoothes away any surface defects. You will be able to see every dent, stretch mark, file stroke, and every stroke of thesand paper. Glass bead blasting can also improve corrosion resistance.
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| Tin Plating |
Tin Plating is used in applications where corrosion resistance is desirable and when plating intricate surfaces or small or deep bores, for a uniform thickness and medium to high hardness. The process is limited to certain types of metals and it requires a strict, high level of quality control. Electrolytic tin is deposited in a direct current process on a cathodically connected product. An aqueous solution of tin salt and a tin anode are used. The use of organic additions to the baths enables decorative bright and functional deposits. Both acid and alkaline tin baths are employed. Apart from pure tin, the metal is also applied as a component in alloy baths, such as in lead-tin
Purpose Of Plating
Tin Plating work improves corrosion resistance, increases the surface hardness of the material, provides a uniform and dense coating, and, in many cases, maintains the same surface finish the material had before plating. Tin Plating consists of the deposition of a Tin alloy onto the metal surface by a chemical bath, not by electrodes or external electrical charges. This permits the plating of hard to reach surfaces, such as small or deep bores and intricate shapes. Coating thicknesses for engineering uses vary from 0.0005 inch to 0.0015 inch
When To Use Tin Plating
Tin plating can be used in the as-deposited condition or may be hardened, depending on the intended service conditions.
- For Corrosion Resistance
- For Wear Resistance in Hard to Reach Areas
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