Abrasives and Bonds by Braemar
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DIAMOND ABRASIVE GRAINS
Diamond wheels are used in grinding carbide, ceramics, alumina, quartz, plasma sprays, composites, and many other dense materials. Natural Diamonds being the first super abrasives used had limited success because of the thermal damage that would occur at 1300F. Today's Synthetic Diamonds can be Copper-coated, Nickel-coated, or UN-coated in multiple sizes and shapes. In most applications Synthetic and Natural Diamonds should be used with a synthetic coolant rather than dry.
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CUBIC BORON NITRIDE (CBN) ABRASIVE GRAINS
CBN wheels are used in grinding Tool Steels, Hardened Alloy Steels, and Super alloys such as Inconel, Hastalloy, Waspalloy, and Rene 41. CBN is a second in hardness to Diamond and will withstand temperatures of 2500F. CBN can be coated or uncoated, a micro or mono structure along with a variety of shapes and mesh sizes. In most situations CBN should be used with coolant oil or water soluble oil.
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BOND TYPES
RESINOID BOND
Resin bond diamond and CBN wheels have a light brown, or green, and possibly a copper color that appears to be a plastic type media. Most resin wheels are molded with powdered phenol formaldehyde resins with the abrasive grains mixed together and heated at a temperature of 350F. After the wheel is fired the plastic resins flow around the abrasive particles and a slow cool down is required to eliminate any thermal damage. Resin wheels can be used wet or dry, coolant is always preferred. Dressing a resin wheel can be easily done with a brake dresser or a SDDD dresser and cleaned with an aluminum oxide dressing stick. Resin bond wheels are more forgiving resulting in a better finish.
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METAL BOND
Metal bond wheels have a gray silver or a bronze copper color. Most metal bonds wheels are made with diamond abrasive for grinding Quartz, Ceramics, and Stone. Metal bond wheels require more pressure than resin wheels sometimes resulting in damage to the work piece. There are advantages with Diamond metal bond applications, Core Drills, Optical Generators, Polishing wheels, and abrasive wheel shaping. CBN metal bond wheels can be used on soft and case hardened steels along with conductive wheels for electrolytic grinding.
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ELECTROPLATED WHEELS
Electroplated wheels have a single layer of abrasive that is plated to a steel blank with nickel matrix. With approximately 30% to 50% abrasive exposure, electroplated wheels have a free cutting action resulting in cooler grinding and faster stock removal with less grinding pressure. No truing or dressing is necessary with electroplated wheels, just mount and indicate within .0002" T.I.R. and use coolant when ever possible. The size and form of an electroplated wheel will remain consistent throughout the life of the wheel eliminating all of the down time of redressing. When your wheel is worn out, return the wheel to us for stripping and replating.
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BRA-Z DIAMOND
Braemar "BRA-Z" products, also single layer, offers a free cutting, long lasting, and fast stock removal rate. With maximum abrasive exposure of the abrasive grains as well as controlled distribution of the abrasive particles providing maximum cutting abilities and abrasive usage.
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