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Composition

Nearly Pure

Copper is malleable and ductile either when cold or hot and can be rolled into sheets or drawn out into the wire.

When the metal has work expended on it as stated or by hammering, it becomes hard and brittle, rendering it unsuitable for practical purposes. To soften the copper it is heated until it acquires a red appearance when it is quenched in cold water.

Properties

It is soft and ductile. It is easy to shape. It is resistant to ordinary corrosion when in contact with water or steam, but owing to its softness it is unsuitable for use with steam or high pressure and temperature.

As it is a good conductor of heat it is required to be lagged to prevent heat loss. Is good electrical conductor and is widely used in electrical work. Its greatest use is in alloying with non-ferrous metals in the production of bronze, gunmetal, muntz metal, nickel-copper and other alloys.



Related Terms

COAXIAL WAVEMETER

A device for measuring frequencies above about 100 megahertz, consisting of a rigid metal cylinder that has an inner conductor along its central axis, and a sliding disk that shorts the inner conductor and the cylinder.

EARTH

Some electrical systems do not use a return wire, but use another conductor instead. The earth's soil is a conductor and this can be used (hence the name). Metal car bodies are also used as a return wire for automotive circuits and are called 'earth-return' circuits. If the negative supply and one side of each lamp was connected to a metal chassis it would be an 'earth-return' circuit. Earth-return circuits are unsuitable for vessels.

BONDING CONDUCTOR

A normally non-current-carrying conductor used to connect the non- current-carrying metal parts of a boat and the non-current-carrying parts of the direct current devices on the boat to the boat's common ground point for purposes of reducing hazards of stray-current corrosion, lightning and accumulated static, and to reduce radio noise.

EARTH RETURN CIRCUIT

Some electrical systems do not use a return wire, but use another conductor instead. The earth's soil is a conductor and this can be used (hence the name). Metal car bodies are also used as a return wire for automotive circuits and are called 'earth-return' circuits. If the negative supply and one side of each lamp was connected to a metal chassis it would be an 'earth-return' circuit. Earth-return circuits are unsuitable for vessels.

PIKE POLE

  1. A pole with a sharp metal point in one end that is used to hold utility poles upright while they are being installed. 2. See fire hook.

COPPER ALLOY

The alloying elements used to have a fair degree of solubility and within this range, the solid solutions formed are soft and ductile and are suitable for cold working. Further additions of the alloying element result in the formation of hard particles, accompanied by an increase in strength and a decrease in ductility. Such alloys are suitable for hot-working and for castings.

Copper-Zinc (Brasses)
Up to 39% zinc - cold working alloys, soft and ductile
39% - 45% zinc - hot working alloys
above 45% - material becomes brittle.
Tin improves corrosion resistance.
Manganese is added for the deoxidization producing sounder castings and for improving tensile strength.
Aluminum increases tensile strength and corrosion resistance.
Nickel increases corrosion and erosion resistance.
Copper-Tin (Bronzes)
Additions of up to 10% tin are soluble in copper and form soft ductile alloys which can be cold-worked. Further additions of tine result in the appearance of a hard constituent, such alloys being suitable for hot-working and for castings. The cold worked alloys are used mainly for coinage.
Admiralty Gunmetal (88: 10: 2, Cu: Sn: Zn)
Zinc is present as a deoxidizer and increases fluidity. This alloy is used mainly for castings requiring strength and corrosion resistance. An additional of 1% lead may be used to improve pressure tightness. The alloy may be used for bearings.
15% Tin - Bronze Alloy
Cast 15% tin bronze is suitable for bearings.
Phosphor - Bronzes
Phosphorus increases strength and corrosion resistance. Alloys containing up to 8% and 0.3% phosphorus can be cold worked and are used for instrument springs and steam turbine blades. Cast alloys contain up to 13 tin and up to 18% phosphorus is used mainly for bearings.
Aluminium - Bronzes
Alloys containing up to 9.4% aluminum are soft and ductile and are suitable for hot and cold working. Further additions result in the appearance of a hard constituent and are used for the hot worked condition and for castings. Aluminum bronzes have good mechanical properties, wear, fatigue and corrosion resistance. The 7% aluminum alloy often contains small additions of nickel, iron and manganese and is used for marine condenser tubes.
The 10% alloy with additions of nickel, iron and manganese is used for propellers.
Copper Nickel Alloys (Monel Metals)
Copper and nickel form solid solutions for all proportions. These alloys may be hot or cold worked and have excellent corrosion resistance. The copper-rich alloys are known as cupro-nickel.(70: 30: Cu: Ni) used for condenser tubes (Cupro-Nickel)
(29.5: 68.5: 1: 1, Cu: Ni: Fe: Mn) Monel Metal. This alloy combines good mechanical properties and high corrosion resistance.
Bearing Metals
Alloys used for bearing should have a low coefficient of friction, be sufficiently hard to resist wear, tough to withstand shock loading, have the strength to support the working load, be sufficiently plastic to allow self-alignment and have high thermal conductivity to dissipate heat when running. The alloys employed usually consist of hard particles in a soft matrix. The hard particles provide the wear resistance while the matrix provides the mechanical properties.

Copper Base Bearing Alloys
Phosphor - bronzes containing 10-13% tin and 0.3 - 1% phosphorus and tin bronzes containing 10-15% tin are used for bearings where loading is heavy. Lead bronzes are useful in that they have a high resistance to wear and have good thermal conductivity enabling the bearings to remain cool. Sintered bearings are made by heating a compressed powder mixture of 90% copper and 10% tin with an addition of graphite. These bearings being semi-porous retain lubricant.

Yorcalbro - Copper - Zinc Alloy

22% zinc 2% aluminium 0.04% arsenic.

BABBITT

A soft, white, non-ferrous alloy bearing material composed principally of copper, antimony, tin and lead.

BASE SCREED

A metal screed with expanded or short perforated flanges that serves as a dividing strip between plaster and cement and acts as a guide to indicate proper thickness of cement or plaster.

SPECULUM

An optical instrument reflector of polished metal or of glass with a film of metal.

CAR SEAL

Metal strip and lead fastener used for locking freight car or truck doors. Seals are numbered for record purposes.

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