GRAPHITE
GRAPHALLOY, a graphite/metal alloy, is formed from molten metal, graphite and carbon; it is a uniform, solid, self-lubricating, bushing and bearing material. From this material we manufacture a unique, self-lubricating bearing solution, offering superior performance in hundreds of applications. GRAPHALLOY material is suited for submerged or high temperature bearings or bushings - applications where oil, grease and plastics fail. Learn more Available in over 100 grades, GRAPHALLOY bearings may be the solution to your toughest bearing, bushing, thrust washer, cam follower, or pillow block bearing design problem. Some GRAPHALLOY bearings have operated for up to 20 years without maintenance. We have many standard designs but most of our products are custom designed to the unique requirements of your specific application. Click here for more information about custom designs. Let us help you find cost effective solutions for your toughest bearing problems. Our engineering staff is ready to tackle your unique application.
GRAPHITE
Lithium-ion batteries are nowadays playing a pivotal role in our everyday life thanks to their excellent rechargeability, suitable power density, and outstanding energy density. A key component that has paved the way for this success story in the past almost 30 years is graphite, which has served as a lithium-ion host structure for the negative electrode. And despite extensive research efforts to find suitable alternatives with enhanced power and/or energy density, while maintaining the excellent cycling stability, graphite is still used in the great majority of presently available commercial lithium-ion batteries. A comprehensive review article focusing on graphite as lithium-ion intercalation host, however, appeared to be missing so far. Thus, herein, we provide an overview on the relevant fundamental aspects for the de-/lithiation mechanism, the already overcome and remaining challenges (including, for instance, the potential fast charging and the recycling), as well as recent progress in the field such as the trade-off between relatively cheaper natural graphite and comparably purer synthetic graphite and the introduction of relevant amounts of silicon (oxide) to boost the energy and power density. The latter, in fact, comes with its own challenges and the different approaches to overcome these in graphite/silicon (oxide) composites are discussed herein as well.
Graphite occurs naturally in igneous and metamorphic rocks, where high temperatures and pressures compress carbon into graphite. Graphite can also be created synthetically by heating materials with high carbon content (e.g. petroleum coke or coal-tar pitch). The carbon-rich material is heated to 2500 to 3000 degrees Celsius, which is hot enough to "purify" the material of contaminants, allowing the carbon to form its hexagonal sheets.[3]
Graphite is extremely soft and breaks into thin flexible flakes that easily slide over one another, resulting in a greasy feel. Due to this, graphite is a good "dry" lubricant and can be used in applications where wet lubricants (like lubricating oil) cannot.[2]
The mineral graphite is a crystalline form of the element carbon, which occurs naturally in various types of rocks. Composed of disk-like particles that readily slide over one another, graphite easily produces marks on paper or vellum that often appear shiny when viewed in obliquely-angled or raking light. This surface quality helps to distinguish graphite drawings from works in black chalk. Graphite was used for drawing in Central Europe during the sixteenth century, but its use became more widespread in the late eighteenth century.
As with other media applied directly to paper without the intermediary of a brush (chalk, charcoal, pastel), graphite can produce a range of linear marks and varieties of tone. When sharpened to a point, it creates narrow, even strokes. Massing elongated hatches (parallel strokes) or cross-hatches (overlapping strokes in a different direction) creates tone.
Unlike many other media, graphite is easily removed from a drawing. For aesthetic reasons or corrections, it may be lifted from the surface of the support using scraping knives or different types of erasers. This allows artists to make changes or create highlights by revealing the bright underlying paper. Traditionally, small pieces of bread were used; today, rubber, vinyl, latex, and gummed erasers are among the many tools commonly employed.
The diverse qualities of graphite provide artists with many creative possibilities. The thin, refined strokes produced by harder, denser sharpened graphite appealed to a neoclassical portraitist such as Jean Auguste Dominique Ingres. Softer grades allow for broader, dark strokes, which are suited to shadowy areas, or for quickly sketched landscapes, as in the work of Thomas Gainsborough.
Over the past three decades, lithium-ion batteries have revolutionized the energy industry due to their lighter weight, longer charges and ability to perform better under extreme conditions compared to the nickel-cadmium batteries of the past. A key component of lithium-ion batteries is graphite, the primary material used for one of two electrodes known as the anode.
When a battery is charged, lithium ions flow from the cathode to the anode through an electrolyte buffer separating these two electrodes. This process is then reversed as the battery discharges energy. While various materials can be used for the cathode, graphite is the go-to material for most anodes, thanks to its abundance, low cost, and long cycle life. Cycle life refers to how long a battery can hold a charge and contributes to technology advancements.
As industries around the globe work to create more powerful lithium-ion batteries to power everything from electric vehicles to grid-scale energy storage stations, graphite plays an increasingly important role. Natural graphite typically contains flakes which need to be converted to a spherical form before they can be used as an anode material. Alternatively, synthetic graphite can be produced in a controlled process to ensure consistent quality. The production of high-quality synthetic graphite requires temperatures as high as 3000C.
Optimizing the morphology of the graphite allows researchers to create anodes with a higher rate capability and energy density, lower first cycle irreversible capacity loss, longer cycle life and better safety performance. Spherical graphite particles allow for more efficient packing of particles, thereby increasing the overall conductivity. Using a scanning electron microscope (SEM), researchers can visually study the morphology of the particles. Scanning electron microscopes have superior resolution compared to optical microscopes, which would prove difficult to use when looking at a black powder such as graphite.
The Phenom XL can generate images at 10 nanometer resolution, which makes it the ideal instrument to image 20-micron graphite particles. Moreover, the intuitive user interface reduces the need for training, extending these analyses to more users.
As scientists around the globe work to improve graphite for lithium-ion battery anodes, the Phenom XL Desktop SEM with dedicated Auto-Scan script can automate the repetitive testing work required. With the ability to quickly and accurately characterize these samples in-house, users can accelerate the R&D process as they work to design safer, more powerful, and longer lasting lithium-ion batteries.
Dry Graphite fibers consist of 95% carbon and are considered the highest strength reinforcements in the industry. Carbon fibers woven together create this Graphite fabric. The most beneficial aspects to this graphite are its lightweight properties, extreme high strength, while maintaining a fatigue and fire resistant stature.
Kroil Penetrant with Graphite is a unique blend of oils, solvents and graphite engineered to penetrate the smallest gaps of corroded metals to loosen seized parts. Eases the removal of large metal fasteners, components and equipment parts. The graphite is designed to stick to metal and provide long lasting lubrication, which will remain in place even in temperatures up to 700F (371C). Made in the U.S.A. 50-State VOC Compliant. 041b061a72