AW additive

AW additive

AW additives, or antiwear additives, are additives for lubricants to prevent metal-to-metal contact between parts of gears.

EP additives are usually used in applications such as gearboxes, while AW additives are used with lighter loads such as bushings.

AW additives typically contain zinc and phosphorus compounds.

Some popular AW additives are:
* zinc dithiophosphate (ZDP)
* zinc dialkyl dithio phosphate (ZDDP), probably the most widely used in formulated engine oils, also acts as a corrosion inhibitor and antioxidant
* Tricresyl phosphate (TCP), used for high-temperature operation, often used as an AW and EP additive in turbine engine lubricants, and also in some crankcase oils and hydraulic fluids
* Halocarbons (chlorinated paraffins), for extreme pressure operations
* Glycerol mono oleate
* Stearic acid, adhering to surfaces via reversible adsorption process under 150 °C, which limits its use to mild contact conditions.

Some formulations use colloidal PTFE (Teflon), but its efficiency is controversial.

Many AW additives function as EP additives, for example organophosphates or sulfur compounds.The mechanism of function of TCP and ZDDP is explained in EP additives.

Under extreme pressure conditions, the performance of AW additives becomes insufficient and designated EP additives are required.

See also:
* EP additives
* Oil additive


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Additive rhythm and divisive rhythm — Additive and divisive meters. In music, additive and divisive are terms used to distinguish two types of both rhythm and meter. A divisive (or, more commonly, multiplicative) rhythm is a rhythm in which a larger period of time is divided into… …   Wikipedia

  • Additive — (lat. additivum „hinzugegeben, beiliegend“), auch Hilfsstoffe oder Zusatzstoffe sind Zusatzstoffe, die Produkten in geringen Mengen zugesetzt werden, um bestimmte Eigenschaften zu erreichen oder zu verbessern. Additive werden eingesetzt, um einen …   Deutsch Wikipedia

  • Additive synthesis — is a technique of audio synthesis which creates musical timbre.The timbre of an instrument is composed of multiple harmonics or partials , in different quantities, that change over time. Additive synthesis emulates such timbres by combining… …   Wikipedia

  • Additive — may refer to:* Additive function, a function which preserves addition * Additive inverse, an arithmetic concept * Additive category, a preadditive category with finite biproducts * Additive rhythm, a larger period of time constructed from smaller …   Wikipedia

  • Additive Farbsynthese — additive Mischung am RGB Monitor Die Additive Farbsynthese (auch Additive Farbmischung, Additives Verfahren, Physiologische Farbmischung oder Additionsverfahren) ist ein optisches Modell, welches das (hinzu)mischen von farbigem Licht beschreibt… …   Deutsch Wikipedia

  • Additive manufacturing — is the process of making a product by adding layers in a relatively efficient way, such that there is little waste or reduction of materials. Two examples are inkjet printing and aerosol jet printing of electronic circuits. In comparison to… …   Wikipedia

  • Additive Eigenschaften — Additive Eigenschaften. Die Beträge gewisser physikalischer Eigenschaften von physikalischen Gemischen oder chemischen Verbindungen lassen sich aus denen der Komponenten und aus ihrem Mengenverhältnis nach der sogenannten Gesellschaftsrechnung… …   Lexikon der gesamten Technik

  • Additive Eigenschaften — Additive Eigenschaften, physikalische Eigenschaften eines Gemisches, die sich aus den betreffenden Eigenschaften der Bestandteile des Gemisches berechnen lassen: die Masse, das spezifische Volumen, das spezifische Brechungsvermögen. Auch die… …   Meyers Großes Konversations-Lexikon

  • additive inverse — the number that must be added to a number to equal zero [−5 is the additive inverse of 5] …   English World dictionary

  • Additive — Ad di*tive, a. [L. additivus.] (Math.) Proper to be added; positive; opposed to {subtractive}. [1913 Webster] …   The Collaborative International Dictionary of English

  • Additive Records — is a subsidiary of EMI and is one of the leading dance music labels in the UK. They have released singles from such artists as Ayla and Noel Sanger. See also * List of record labels * List of electronic music record labelsExternal links*… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”