صفر (نحاس أصفر)
صـُـفـْر (نحاس أصفر) Brass
الصفر (بضم وتشديد الصاد وتسكين الفاء, وتجمع كمفردها صفر أو أصفار بحسب المعجم الوسيط) هو أشابة (سبيكة) أساسها النحاس النقي والزنك أو الخارصين ويمكن أن تحتوي قدراً ضئيلاً من عناصر أخرى و يطلق عليه (النحاس الأصفر) وهى تقاوم فعل العوامل الجوية وتصنع منها بعض القوالب وأواني طبخ مواد الأسنان الصناعية.
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أنواع الصفر
- Admiralty brass contains 30% zinc and 1% tin which inhibits dezincification in most environments.
- Alpha brasses (Prince's metal), with less than 35% zinc, are malleable, can be worked cold, and are used in pressing, forging, or similar applications. They contain only one phase, with face-centered cubic crystal structure.
- Alpha-beta brass (Muntz metal), also called duplex brass, is 35-45% zinc and is suited for hot working. It contains both α and β' phase; the β'-phase is body-centered cubic and is harder and stronger than α. Alpha-beta brasses are usually worked hot.
- Aluminum brass contains aluminum, which improves its corrosion resistance. Used in Euro coins (Nordic gold).
- Arsenical brass contains an addition of arsenic and frequently aluminium and is used for boiler fireboxes.
- Beta brasses, with 45-50% zinc content, can only be worked hot, and are harder, stronger, and suitable for casting.
- Cartridge brass is a 30% zinc brass with good cold working properties.
- Common brass, or rivet brass, is a 37% zinc brass, cheap and standard for cold working.
- DZR brass is Dezincification resistant Brass with a small percentage of Arsenic.
- High brass, contains 65% copper and 35% zinc, has a high tensile strength and is used for springs, screws, rivets.
- Leaded brass is an alpha-beta brass with an addition of lead. It has excellent machinability.
- Low brass is a copper-zinc alloy containing 20% zinc with a light golden color, excellent ductility and is used for flexible metal hoses and metal bellows.
- Naval brass, similar to admiralty brass, is a 40% zinc brass and 1% tin.
- Red brass, while not technically brass, is an American term for CuZnSn alloy known as gunmetal.
- White brass contains more than 50% zinc and is too brittle for general use.
- Yellow brass is an American term for 33% zinc brass.
- Gilding metal is the softest type of brass commonly available. An alloy of 95% copper and 5% zinc, gilding metal is typically used for ammunition components.
انظر أيضاً
- قائمة السبائك
- Copper alloys
- Calamine brass — brass alloy and manufacturing process from discovery until the late 18th century
- Gilding metal; the softest form of brass commonly available
- Corinthian brass — an alloy of gold, silver and copper, known to antiquity
- Pinchbeck — a brass that closely resembles gold in appearance.
- Bronze — an alloy of copper with tin and optionally zinc, silicon, nickel and other metals
- Cupronickel — an alloy of copper with nickel
- Tombac — an alloy of copper with zinc
- Brass instrument — a musical instrument usually made of brass
- Brass rubbing — reproduction of brasses, commemorative plates laid down in British and European churches from the 13th Century onwards
- Brass bed — history of the usage of brass in beds and bedframes
- Latten — early brass alloys (Calamine brasses)
- Season cracking — attack of brass by ammonia