COPPER ALLOYS

1. History and manufacturing of the copper

The copper is the oldest metal all over the world since it has been used more than 8000 years before our era in many Near Eastern areas. From the very beginning, only the Lake copper, that is to say the pure copper without composition with other components, was used ; it came from various sites and among others from Cyprus that has given its name: Aes Cyprium.

The elders represented the copper by the symbol , that is the modified form of the Egyptian hieroglyph meaning "for life", that was the manner to indicate the durability of the copper.

Gold and silver that was, with the copper, the metals more often found in the native form, have also been used very early but only as decorations, while the copper was also used to make useful objects. Many of these ones have been manufactured by the Egyptian, the Chaldean and other peoples from the Middle East.

Because the copper ores naturally contained various impurities or may be because the mixing were fortuitously made, some alloys were worked out such as the copper with arsenic or the copper with bronze, the copper of copper and tin dates back 3500 years B.C. That last alloy is going to take a large place by giving its name to a era of our civilization, the Bronze age, long time before the iron that only appears about 1800 B.C.

In the Western Europe, the copper and the bronze only appear about 2000 years B.C. Greek people knew some highly elaborated processes to cast the bronze, of which the principle is still used today for the precise casting. One of the seven wonders of the world, the Colossus of Rhodes, achieved in 290 B.C., has been made by beating some copper sheets on the wood moulds.

Then, some other alloys are created in the Near East but also in China:
- Copper with lead and with antimony alloys in Chaldea;
- Brass, copper and zinc alloys, are commonly used during the Roman Empire.

The creation of the powder has allowed to use the bronze in great quantities in the artillery manufacturing. The first scientific instruments such as compass, scales and most of the metallic parts used on the ships was in copper or in brass due to their inalterability.
But during about four millennium, there has not been a lot of changes. In fact, it is only in the XIX century that new alloys, so new processes, appear.
The discovery of the electricity has given the modern using of the copper, the power conductor use. At the same time, the birth of the industry has occured the perfecting of many alloys such as special brass for the the laying of ship hulls (Admiralty metal at 1% of tin), the cupro-aluminum created in 1855 by Henri Sainte-Claire-Deville, or the cupro-nickel (Monel).

The world production of copper is about 9 million tons by year, and does not increased since several years.

The manufacturing of the copper includes three steps:
- ore mining and dressing,
- manufacturing of " blisters ",
- refining of blisters to produce the copper.

The copper is lightly present into the earth's crust, about 0,0005 %. It no longer exists at the the native form like in the Antiquity. Today, it is in salts form and contains from 30 to 90 % of copper mixed with other ores; the copper ores look like two forms: oxide ores and sulfurous ores that are the most widely used et that represent more than 80 % of the world production; these last ones have a copper content varying from 0,7 to 2 %. In the largest opencast ore of the world, located at Chuquicamata in Chile, the ratio waste / ores is 3 for 1.
The first step of the sulfurous ores treatment for getting product dressings consists in screening, crushing, grinding and dressing processes that transform them in a crude powder that is after sprinkled with water. By a flotation then decantation treatment, a concentrate containing from 25 to 40 % of copper is obtained.

The manufacturing of blisters comes from these concentrates. In a first time, at liquid state with some flux, the other ores are separated from the heavier copper salts by gravity and by roasting; a matt is obtained heavily loaded in sulfur containing from 40 to 60 % of copper. Then, in a barrel furnace at 1300 °C, the copper is separated from the other compounds contained in the matt; that process gives blisters containing from 98 to 99,5 % of copper, that look like plates of which the oxided surface is blistered that's why they are called "blisters".

The blisters must be refined to obtain the purity of 99,90% of copper, industrially used. There are two refining processes:
- the heat refining that consists of remelting the blister by oxiding it to eliminate the impurities as oxides that volatilize. During that treatment, the copper gets from 0,6 to 0,9 % of oxygen of which the main part must be eliminate; that is done by introducing in the liquid copper bath some green wood trunks. Then, the copper still contains from 0,02 to 0,04 % of oxygen, that's why it has not much industrial uses.
- the electrolytic refining that transforms the blister that has before been cast from plates called anodes into cathodes by the electrolysis process of the soluble anode. The obtained copper is pure but not enough for using it because of its porosity.

So, the cathodes are remelted in accordance with various processes that give the different qualities of copper used in the industry:
- the Cu-a1, or Cu-ETP, is obtained by remelting in air and that contains the oxygen,
- the Cu-b1 and Cu-b2, or Cu-DHP and Cu-DLP, are obtained by remelting in air and deoxided by adding phosphorous,
- the Cu-c1, or Cu-OF, is obtained by remelting in reducing atmosphere (azote and carbon monoxide)

The copper can easily be recovered because the waste during the metallurgical treatments of the remelting and the transformation are weak. The copper does not degrade because its surface oxidation is weak. The recycling can in theory be proceed endlessly because the copper does not lost very much of its substance during their successive uses and keep its intrinsic qualities intact; 75% of the cuprous products on the market are salvaged. The end-of-life products are salvaged after deposit and separated from the other associated products such as insulating materials, the iron, the zinc... Then, they are refined and after the copper is cast for becoming some products for transformers.

Summary

2. Technical and economical advantages

The copper is the second non-ferrous metal industrially used, after the aluminum, thanks to its outstanding properties.

- the copper is the best power and heat conductor. It is its main characteristic. The power conductivity of copper Cu-a1 (Cu-ETP) annealed has been referred by the International Electrotechnic Commission in 1913; by definition, it is equal to 100 % IACS (International Annealed Copper Standard). Only the silver has got a higher conductivity (about 106 % IACS). The corresponding electric resistivity, at 20°C, is 1,7241 10-8 W.m.
By comparison, the electric conductivity of the pure aluminum is 63 % IACS.
The solidity of a copper wire, the reliability of the electric contacts are the main reasons for which the copper is largely used in all electric and electronic industry. For example, 95 % of the conductor wires on an Airbus are in copper.
The heat conductivity of the copper is also the most important of all industrially used metals. It is at 20°C 389 W.m-1.K-1, compared with the one of the aluminum that is equal to 231 W.m-1.K-1, that is to say 59 % of the heat conductivity of copper. That property takes largely advantage in water heater, boilers, car radiators, condensers and heaters of the electric power plants and atomic energy plants.

- the copper is a non magnetic metal.
Its relative magnetic permeability is 1,000, that is to say lightly lower than the one of the aluminum and 50 times lower than the one of steels. Adding to its conductivity, that property allows to use the copper in a large range of processes in clock-making, electric and electronic structures and in navy armament industries.

- the copper has got a great corrosion resistance.
The copper has not a great affinity for the oxygen at solid state. The copper and its alloys are neither etc.hed by water nor by most of the chemical products. That characteristic allows to use the copper and its alloys in a lot of processes : water supply conduits, tanks and containers, faucets; the pumps and conduits for sea water are manufactured only in copper alloys. The copper roofs brave the time: the copper that is subject to the bad weathers, turns dark brown in a first time, then it takes a very adhesive bright green patina that protects it from any later oxidation.

- the copper is greatly easy to be stretc.h formed.
It is greatly ductile. Non-alloyed, there is almost no limit in its cold working. It is easily rolled in sheet, can be hammered in very thin sheets and it stretches in extremely thin wires.

- the copper is a well-designed metal.
With gold, it is the only clearly coloured metal. Besides, gold in jeweller's contains until 15 % of copper. Its natural colour is salmon pink, but it often appears red further to its superficial oxidation. That colour is in great demand for decoration as well as the more or less strong yellow colour of its alloys with the zinc, the brass.

- the copper has got biological properties.
The copper is necessary for life; the living organisms contain from 1 to 10 mg by kg. Human being and the animals need every day to take some milligrams of copper for the formation of the haemoglobine in blood.
The copper has got bactericidal properties; it destroys the micro-organisms and the bacterium and purifies the pipework; it is used for the water supply, the production of beer and jams, distillation of alcohols. The copper and its alloys with the nickel are used on the under sea water structures such as anti-fouling, keeping from the seaweed and sea organism fastening.
The copper salts, such as the sulfate or oxychloride are used as fungicides in wine growing and in farming.

The copper is a heavy metal. Its mass-volum is 8,96 kg/dm3, then higher than the one of the iron (7,86 kg/dm3); in addition, it is much more expensive; in spite of these disadvantages, for an equal electrical conductivity, the price of a copper conductor is equal to 30 % of the price of an iron conductor.

Summary

3.The effects of alloys components

The mechanical strength of the pure copper is rather low, such as a lot of pure metals. That one can be significantly increased by adding some other metals to form the alloys. The differences among the alloys are essentially due to the main addition agent but also to some other addition agents in least quantity, the secondary agents. Some agents are found in the alloy but have not been voluntarily added, the impurities, and some of them can be harmful in some processes.
All agents play a role either by their nature or by their content, on several alloy properties:

* the mechanical characteristics (ultimate tensile load Rm, yield strength Rp02, breaking elongation A%, hardness HV),
* the mass-volume,
* the electrical and heat conductivities,
* the machinability,
* cold and hot deformability.

The copper can be alloyed with a great number of agents that allows to make various alloys having a large range of properties required in a lot of processes. It is possible to introduce in the copper until 100 % of nickel, 40 % of zinc, 25 % of tin and 15 % of aluminum.

The copper alloys are classified in several families and in each one, a great number of alloys are classified according to their addition agents content:

Pure coppers: copper content more than 99,90 %
Lowly alloyed coppers: the addition agents content is less than 5 %
Copper + zinc : binary brass
Copper + zinc + lead: brass with lead
Copper + zinc + others: complex brass
Copper + tin: bronzes
Copper + tin + zinc : chrysocales
Copper + aluminum : cupro-aluminums (bronzes of aluminum)
Copper + nickel : cupro-nickels
Copper + nickel + zinc : German coppers (invented by Maillet and Chorier)

The following chart shows the designations of the main alloys and compares the French and foreign designations.

France	ISO CEN	Germany		USA	Great Britain
Pure coppers
Cu-a1	Cu-ETP	E1-Cu58	2.0061	C 11000	C 101
Cu-b1	Cu-DHP	SF-Cu	2.0090	C 12200	C 106
Cu-c1	Cu-OF	OF-Cu / SE-Cu	2.0040	C 10200	C 103
Lowly alloyed coppers
Cu Te	Cu Te (P)	Cu Te P	2.1546	C 14500	C 109
CuCrZr	CuCr1Zr	CuCrZr	2.1293	C 18100	CC 102
CuBe1,9	CuBe2	CuBe2	2.1247	C 17200	CB 101
Binayry brass
CuZn30	CuZn30	CuZn30	2.0265	C 26000	CZ 106
CuZn33	CuZn33	CuZn33	2.0280	C 26800	-
CuZn37	CuZn37	CuZn37	2.0321	C 27400	CZ 108
Brass with lead
CuZn36Pb3	CuZn36Pb3	CuZn36Pb3	2.0375	C 36000	CZ 124
CuZn38Pb2	CuZn38Pb2	CuZn38Pb1,5	2.0371	C 37700	CZ 128
CuZn39Pb2	CuZn39Pb2	CuZn39Pb2	2.0380	-	CZ 120
CuZn40Pb3	CuZn39Pb3	CuZn39Pb3	2.0401	C 38500	CZ 121
Complex brass
CuZn40Pb1Al	CuZn41Pb3	-	-	C 38600	CZ 130
CuZn38Sn1	CuZn38Sn1	CuZn38Sn1	2.0530	C 46400	CZ 112
CuZn22Al2	CuZn20Al2	CuZn20Al2	2.0460	C 68700	CZ 110
CuZn23Al4	CuZn26Al4	CuZn25Al5	-	C 86200 C 86300 C 86700	HTB 2
Bronzes
CuSn9P	CuSn8P	CuSn8	2.1030	C 52100	PB 104
CuSn12P	CuSn12Pb2	G-CuSn12	2.1052	C 90500	PB 2
CuPb10Sn10	CuPb10Sn10	G-CuPb10Sn	2.1176	C 93700	LB 2
Chrysocales
CuSn3Zn9	-	-	-	C 42100	-
CuPb5Sn5Zn5	CuPb5Sn5Zn5	CuSn5ZnPb	2.1090	C 83600	LG 2
CuSn7Pb6Zn4	CuSn7Pb7Zn3	CuSn7ZnPb	-	C 93200	LPB 1
Cupro-aluminums
CuAl9Ni3Fe2	CuAl9Ni3Fe2	CuAl9Ni3Fe	2.0970	-	-
CuAl9Ni5Fe3	CuAl10Ni5Fe4	CuAl10Ni5Fe4	2.0966	C 63000	CA 105
Cupro-nickels
CuNi44Mn	CuNi44Mn1	CuNi44Mn1	2.0842	-	-
German copper
CuNi12Zn24	CuNi12Zn24	CuNi12Zn24	2.0730	C 75700	NS 104
CuNi18Zn27	CuNi18Zn27	CuNi18Zn27	2.0742	C 77000	NS 107

ISO : International Standard Organization (World standards)
CEN : Comité Européen de Normalisation (European standards)

Summary

4. The effets of manufacturing conditions - Tempers

It is possible to increase the mechanical resistance of the copper and of all its alloys by cold forming, called strain-aging. That process simultaneously decreases the cold workability of the alloys that it is possible to make them recovered by a heat treatment annealing that gives its minimum mechanical resistance to the metal.
Some copper alloys harden faster than some others for the same forming; it is used to say that these alloys have a fast setting strain-aging.

The strain aging produces effects on several alloy properties:

- the ultimate tensile load, the elastic strength and the hardness increase while the breaking elongation and the cold workability decrease,
- the electric conductivity decreases.

The heat treatment annealing produces the opposite effects.

The strain aging is the most used process for hardening the copper alloys; only some alloys can also be hardened by heat treatment solution - quenching - temper annealing. Most of the time, these alloys are besides hardened by quenching - strain aging - temper annealing.

Between the the annealing state and the hardest state that is normally produced, there are some intermediary states; these states of which the reached hardness levels are growing can be obtained by two ways: either from a completely annealed alloy and by strain aging it partially, or from a completely strain aged alloy and by annealing it partially (partially annealed state); the strain aging introduces some internal stresses to the meatl and it is necessary for some processes to cancel them by a stress relief treatment that does not modify very much the mechanical characteristics of the alloy.

The following chart shows the standardized designations of the strain aging state in the French standard NF A 02-008 from September 1986; that standard has been cancelled and replaced by the European standard NF EN 1173 from May 1996 detailed below; that French designation are nevertheless given here because they will be used in the usual vocabulary for a long time yet.

Hardness level	Strain aging state	Partially annealed	Stress relief state
Annealing	O	-	-
1/4 hard	H11	H21	H31
1/2 hard	H12	H22	H32
3/4 hard	H13	H23	H33
4/4 hard	H14	H24	H34
spring	H15 H16 H17	-	-

Some alloys can be hardened by heat treatment; the designations of the corresponding states in the standard NF A 02-008 are rarely used; it is better to used the following designations:

TR : quenching - tempering
TE : quenching - strain aging
TER : quenching - strain aging - tempering
TRE : quenching - tempering - strain aging

These alloys are lowly alloyed coppers such as the CuCr, the CuCrZr, the CuFe, the CuCo (TER or TRE), the CuNiSi (TER), the CuBe2, the CuCoBe and some cupro-nickels (TE or TER).

The standard NF EN 1173 does not indicate the products states by the manufacturing or / and heat treatment processes; the designations are based on the level of one of some standard characteristics and, if the case arises, on any added special treatment such as the stress relief treatment. The state designation is made by a letter followed by some 3 or 4 figures. The letter indicates the obligatory characteristic and the figures indicate the minimum value of that specified property in the standard of the product. Letters are the following:

A = Breaking elongation
B = Elastic strength
D = As-drawing, without mechanical characteristics requirement (non followed by a figure)
G = Grain size (the figures indicate the median value)
H = Hardness Brinell or Vickers
M = As-manufacturing, without mechanical characteristics requirement (non followed by a figure)
R = Tensile strength
Y = Conventional yield point at 0,2 %

Summary

5. Typical features of alloys and delivery states

The followng chart shows the typical values about the components and the mass volume of some usual alloys.

Alloy	Compound in %														Mass Volume kg.dm³
	Cu	O	P	Te	Cr	Zr	Be	Zn	Pb	Sn	Mn	Al	Ni	Fe
Cu-a1	99,9	200	-												8,90
Cu-b1	99,9	10	380	-											8,94
Cu-c1	99,9	10	-												8,94
CuTe	*	-	380	0,5	-										8,94
CuCrZr	*	-			0,8	0,15	-								8,94
CuBe2	*	-					2,1	-							8,50
CuZn33	67	-						*	-						8,50
CuZn36Pb3	61	-						*	3	-					8,50
CuZn40Pb3	58	-						*	3	-					8,50
CuZn38Sn1	60,5	-						*	-	0,85	-				8,45
CuZn23Al4	63	-						23,5	-		3,25	4	-	2,25	7,80
CuSn9P	*	-	0,2	-						8,75	-				8,80
CuAl9Ni3Fe	*	-										9,15	3	2	7,70

N.B. : The copper contents of Cu-a1, Cu-b1 and Cu-c1 are the lowest.
The contents in O and P are in ppm.
* = the rest.

The following chart indicates the typical features of the mechanical, physical characteristics and the implementation properties of these alloys.

Alloy	State	Mechanical characteristics			Cond. électri. % IACS	Corrosion resistance sea water	Weldability	Machinability	Deformability
		Rm N/mm²	Rp02 N/mm²	A %
Cu-a1	O H14	230 350	60 320	45 6	100 96	B B	D D	D D	A C
Cu-b1	O	230	60	45	90	B	A	D	A
Cu-c1	O	230	60	45	102	B	A	D	A
CuTe	H14	350	320	6	90	B	C	A	B
CuCrZr	TER	470	400	15	80	B	B	C	C
CuBe2	TER	1390	1230	2,5	22	B	B	C	D
CuZn33	O H14	340 525	120 430	60 8	28 24	C C	C C	C C	A C
CuZn36Pb3	H	390	300	24	26	C	D	A	C
CuZn40Pb3	H	430	350	15	28	C	D	A	D
CuZn38Sn1	O	400	200	40	25	B	C	C	C
CuZn23Al4		700	400	19	23	A	C	C	B
CuSn9P	O H14	405 740	210 730	50 5	12 8	A A	C C	C C	B D
CuAl9Ni3Fe2	O	690	250	16	17	A	B	C	C

A : very good ;B : good ;C : average ; D : bad, non recommended.

Summary

6. Classification of alloys by using

Machining - Screw cutting - Power conductor - Abrasion resistance - Corrosion resistance -
High mechanical resistance -

Machining - Screw cutting

The machinability of an alloy is generally estimated with 4 criterions:
- the surface condition of parts,
- the speed cutting that conditions the productivity of the machines,
- the chip breaking, important criterion for the productivity and the reliability of the automatic machines,
- the lifetime of the cutting tools, that is an economical criterion but also a technical one due to its effects on the precision of the produced parts.

The pure copper has not a great machinability. On the other hand, some of its alloys have some excellent machinabilities, especially at high speed.
The cuprous alloys can be divided in 3 groups according their machinability, noted by an index that includes in a simplistic way the above-mentioned criterions.

* Group I : screw cut alloys (index from 70 to 100)
That are all copper alloys that contain lead and especially brass with lead. The CuZn40Pb3 is considered as the worldwide champion of all metals; the index 100 is attributed to it and all others are classified in regard to it. In addition to these lead alloys, the CuTe as well as the CuS must be added..

* Group II : average machinability alloys (index from 30 to 65)
That are brass without lead with a zinc content less than 28 %, complex brass and German copper.

* Group III : bad machinability alloys (index from 20 to 25)
That are pure coppers, almost all lowly alloyed coppers, binary brass of which the zinc content is less than 20 %, bronzes, cupro-aluminums and cupro-nickels.

The following chart shows, for comparison, the machinability indexes of some cuprous alloys and some irons or cast irons.

Alloy	Designation	Index
Screw cutting brass	CuZn40Pb3 CuZn36Pb3 CuZn39Pb2	100 95 85
Binary brass	CuZn33	40
Bronze	CuSn9P	25
Alloyed iron	35CD4	20
Ferritic cast irons	Cast ironGS	15

Power conductors

The pure copper has the lowest electrical electricity among all industrial metals. The addition of the alloy agents systematically increases that resistivity accordingly to the agent; that rising, in micro.W.cm by % of agent is:

silver:	0.22
zinc:	0.29
oxygen:	0.36
tin:	1.65
aluminum:	2.22
iron:	10.6
phosphor:	14.3
sulfur:	18.6

The alloys used for their strong conductivity, more than 60 % IACS are the coppers and some lowly alloyed coppers such as the CuAg, the CuCd, the CuTe, the CuS at annealed or strain aged state, the CuCr, the CuCrZr, the CuFe and the CuCo at the state TER. The other alloys have got a conductivity less than 50 %, that make them at the same level than the aluminum alloys, or even the steels:

CuBe2 TER :	22 % IACS
brass:	23 à 56 % IACS
bronzes:	10 à 20 % IACS
cupro-aluminums	8 à 16 % IACS
cupro-nickels:	3 à 15 % IACS
German coppers:	6 à 9 % IACS

coppers:	2 à 4 % IACS
lowly alloyed coppers:	4 à 8 % IACS
CuBe2 TR :	10 % IACS
brass:	2 à 5 % IACS
bronzes:	1 à 2 % IACS

The alloys that can be hardened by heat treatment allow a great number of combinations Ultimate tensile load - Conductivity by playing on the parameters of the tempering and the strain aging between quenching and tempering; in fact, the tempering treatment notably increases the conductivity of the metal at the same time than its breaking stress. The Cu0.8%Cr is an example: :

State	Rm (N/mm²)	% IACS
Quenching	250	25
Quenching Tempering	450	75

Abrasion resistance

For many rotary machines, some cuprous alloys show, when they are in contact with the steel, very interesting antifriction properties; they are used as bearings, slide rods, rings, sprocket wheels, nuts and for toothed wheels. These alloys are often used as continuous cast product because, in that case, their efficience is better and more regular.

The required qualities in an antifriction alloy are wear resistance under pressure, seizing resistance and endurance limit; a good conductivity is sometimes necessary to eliminate the emitted heating, but the temperature of these used alloys is normally limited by the lubricants at 200°C.

The friction cuprous alloys - steel always requests a lubrication of the contact, but that one can vary:
- the film lubricant is continuous, with a whole separation of metals, for the linear speeds more ore equal to 0,2 m/s; the used cuprous alloys are the bronzes such as the CuSn9P, CuSn12P, CuSn5Pb5Zn5 and CuSn7Pb6Zn4, when the contact pressures do not exceed 600 kg/cm² and the CuAl9Ni3Fe2 and CuAl9Ni5Fe4 that can support pressures until 2000 kg/cm².
- the lubrication is limited and the contacts steel-steel are frequent for speeds less than 0,05 m/s or irregular. In that case, seizing and erosion risks are important ; so the alloys containing lead are necessary, such as the CuPb10Sn10.

Corrosion resistance

The copper is of course less noble than the precious metals, platinum, gold and silver, but it is more than all the other metals. Its affinity for the oxygen is low.
The copper oxidation in the air produces a superficial layer that considerably slows the oxidation kinematics without that stopping it however.
The copper cannot reduce the hydrogen in the water and so corrodes theoretically only in the aerated water containing some dissolved oxygen; that corrosion produces a insulating layer that protects the copper against any later attacks.
The copper Cu-b1 (Cu-DHP) is very largely used for the manufacturing of sanitory tubes and temperature exchangers; in that case, it is reserved for easy conditions when waters are lowly charged in salts and the circulation speed is less than 1,50 m/s.
In the case of sea water, and in particular for the heat exchangers, it is used the copper alloys still more resistant such as the cupro-nickels and the cupro-aluminums that alloy mechanical strength and corrosion resistance.

The brasses are particularly sensitive to two special forms of corrosion:
* the corrosion under stress, when the zinc content is more than 20 %, with some aggressive agents, in particular wet ammonia; that effect is known under the name of season cracking. For avoiding that effect, the internal stresses at the end of the manufacturing must be eliminated by a heat stress relief treatment.
* the dezincification: the dezincificated surface area is replaced by a porous layer of copper that is no longer solid. That dezincification mainly occurs in contact with almost aggressive waters. For the brasses containing less than 36 % of zinc, that effect is totally cancelled by the addition of arsenic.

High mechanical resistance

Most of the copper alloys, when they are strongly strain-aged, can show an ultimate tensile load that reaches 400 N/mm², but it is generally to the detriment of the electrical conductivity.
Only the age-hardening alloys at the state Quenching-Strain-ageing-Tempering can show an utlimate tensile load that exceeds, largely for some ones, 400 N/mm² and show at the same time an important conductivity.
It is why they are used in the springs and the electrical contactors.
For example, the following alloys-states can be mentionned:

Alloys	States	Rm N/mm²	% IACS
CuFe0.1P	TER	400	92
CuFe2P	TER	460	65
CuCo 0.3P	TER	465	85
CuNi3Si	TER	740	35
CuSn9P	H15	820	10
CuNi14Al2	TER	850	10
CuCoBe	TER	860	48
CuNi15Sn8	TER	1240	8
CuBe2	TER	1390	22

Using examples and main used alloys:

Electricity, electronics, connector engineering
Contacts CuBe2, CuCoBe, CuFe
Cables and electrical wires, conducting bars Cu-a1
Connections, electronic components, Cu-a1, Cu-c1, CuBe2, CuFe
Printed circuits
Home sockets, switches Brasses

Industrial and civil engineering vehicles s
Rings, bushings, gears Bronzes
Radiators, thermostats Cu-b, brasses
Cabling and connections for braking circuits Brasses

Industry
Machine tools Bronzes, brasses
Pinions, rings, bushings Bronzes
Springs, diaphragms Bronzes
Exchangers Cupro-nickels, cupro-aluminums
Structures of pumps chemestry and petroleum Cupro-nickels, cupro-aluminums
Stationery filters Brasses
Screw industry, bolt industry Brasses

Weaponry
War and hunting munitions CuZn30
Shells

Decoration, luxury goods
Silversmith's trade, jewellery Brasses
Plates, Cutlery German coppers
Watchcases Brasses
Glass industry German coppers
Push buttons CuZn30
Ball point pens, lighters, buckles of belts Brasses
Musical instruments Brasses, German coppers

Navy
Propellers, rudders, pumps Bronzes, cupro-aluminums
Waterworks and marine fittings Cupro-nickels and
desalination parts cupro-aluminums
Off-shore oil rigs Cupro-nickels, cupro-aluminums
Protection of ships hulls Cu-a1
Oysters beds, aquaculture cages Cupro-nickels

Summary

7. Shape of delivered products

7.1 Long products

They are most often obtained by extrusion and stretching or by wiredrawing.

Bars: full products delivered in straight length of which the section is the same all along the length and have a round, square or hexagonal shape (called hex nut)

Cored bars: cored products delivered in straight length of which the section is the same all along the length and have an internal round shape and outside a round, square or hexagonal shape.

Tubes: cored products delivered in straight length of which the thickness is the same all around the section; that one may have a round or square shape.

Wires: round shape products and in very large length delivered in coils.

Flats: products delivered in straight length or in coils with a rectangular section of which the ratio width on thickness does not exceed 10.

Sections: products delivered in straight length or in coils of which the section may have a simple shape, in L, also called angle, in U, in T or a more complex shape that requires a sized drawing. They are often classified by their weight by meter.

7.2 Fats products

They are mainly obtained by rolling; their section is rectangular and the ratio width on thickness is more than 10.

Sheets: rolled products that are laid down flat; their length is a delivery size.
Thin sheets of which the thickness is generally less than 10 mm and the strong plates can be distinguished. They are also called straight strips or flat strips.

Coils : they are the same products than the thin sheets delivered in coils.

Summary

8. Implementation technology

8.1 Machining
The cuprous alloys containing some lead have got a excellent workability by cutting tools and in particular the brasses that serve as a base in the matter.
For these alloys, the usual parameters are the following ones:
* Angles of traveling head shaping tools:
- face draft 6°
- lateral draft 6°
- tool rake 2°

Process	Speed		Depth of pass		Feed
	m/min		mm		mm/tr
	AR	C	AR	C	AR	C
Traveling head shaping	90 to 140	80 to 340	1 to 4	1 to 10	0,1 to 0,15
Drilling	35 to 55	90 to 130	-	-	1% to 1,5% of Diam
Cutting off	70 to 110	145 to 215	-	-	0,1 to 0,15	0,1 to 0,2

AR: high-speed steel ; C: carbide

8.2 Heat treatments

The following chart shows the temperature ranges to be used for various alloys and various kinds of heat treatments.

Alloy	Annealing	Stress relief	Solution treatment	Tempering
Cu-a1	300-400°C	-	-	-
Cu-b1	350-500°C	-	-	-
CuAg	450-600°C	-	-	-
CuCrZr	-	-	950-1000°C	425-500°C
CuBe2	-	-	760-800°C	310-360°C
CuZn33	450-550°C	250-325°C	-	-
CuZn40Pb3	480-580°C	250-325°C	-	-
CuSn9P	500-700°C	200-350°C	-	-
CuAl9Ni3Fe2	800-850°C slow cooling	300-400°C	-	-
CuNi14Al2	-	-	925°C	525-550°C

8.3 Assemblying processes

Welding

The copper and its alloys show some characteristics that must be taken into account:
- the high heat conductivity requires some important calorific powers and oftenly a pre-heating of parts,
- the high fluidity of the liquid metal requires sometimes a support on the reverse side of the welding,
- the liquid metal is able to dissolve the gas that brings about some risks of cavities when it is solidified,
- the ability of the liquid copper to dissolve its own oxide leads to a embrittlement, either by water steam if the flame of the blowpipe is reducing, or by concentration of oxides at the grain boundaries when it is solidified,
- the brasses containing from 60 to 65 % of copper have a brittleness area from 300 to 500°C,
- the cupro-aluminums have a brittleness from 450 to700°C,
- some of the alloys have some volatile agents at welding temperatures; it is the case for the CuTe that is better to braze and brasses, German coppers and chrysocales for which a oxiding flame must be used for limiting the volatilization of zinc,
- the alloys hardened by heat treatment lost that hardening in the welded area.

The most used welding processes are:

* the arc welding under inert gas, TIG process (Tungsten Inert Gas) for the thicknesses less than 6 mm, and MIG process (Metal Inert Gas),
* the welding with oxyacetylenic blowpipe,
* the welding with plasma blowpipe for the very low thicknesses,
* the welding by electron bombardment for the large thicknesses,
* the welding by induction,
* the welding by pressure and friction,
* the welding by ultrasonics.

Brazing

The products to be assemblied by brazing are submitted to lower temperatures than for the welding and the precautions of use are not in great number; nevertheless, the following points must be taken into account:
- the high heat conductivity of the copper requires a quite important calorific power,
- the hot brittleness areas of brasses and cupro-aluminums are at some temperatures reached when brazing,
- the reached temperatures partially destroy the age-hardening of quenched-tempered alloys,

For the soft brazing, the addition metal has a melting temperature less than 450°C, so the alloys tin-lead, lead-tin-silver, tin-silver or tin-antimony are used.

For the strong brazing, the alloys such as copper-silver, copper-silver-cadmium-zinc, complexe brasses or phosporous copper are used.

Summary

9. Précautions of use

The products in copper have a brittle surface. They are sensitive to the shocks and the scratches.
In addition, the products are not totally rigid and can be deflected. It is obligatory to handle and to store them by taking some précautions:
- to avoid all shocks with metallic parts,
- not to store the products directly on other products,
- to avoid the frictions with other products,
- if the vertical storage is not possible, the products must be stored horizontally with enough supports so that the products are not deflected.

The copper products, even if they are protected by the oxide layer at the surface, are sensitive to the corrosion:
- the products that have been wet must be completely dried before storage,
- all the condensation effects must be avoided: the condensation occurs when the products come from outside where it is cold and are stored in a heat warehouse. The products must be displayed and let them warm up slowly in a well-ventilated place.
- the natural oxide layer has a thickness about 50 Å (5.10-6 mm); it is attacked by the strong acids, hydrochloric, sulfuric or nitric acids.

In case of contact with other metals with a conductive fluid used as electrolyte, such as sea water, it is often the other metal that is attacked, but that can vary from a cuprous alloy to an other one; the following chart shows the differences of potentials, in mV, among the pure copper and various alloys and metals; when that difference is positive, the copper is attacked; the corrosion risk exists when that difference is over than 150 mV.

Graphite	610	CuNi30	150	Brass	-10
Platinum	570	Nickel	140	CuAl	-40
Gold	440	CuNi20	110	Steels	-310
Titanium	300	CuNi10	90	Aluminum	-500
Passive stainless steel	290	Maillechorts	80	Chromium	-550
Silver	230	Bronzes	70	Zinc	-680
CuAlNi	150	Tin	20	Magnesium	-1280

Copper strength according to the impurities:

Pure Cu	1.6753 10-8	1.7241 10-8 W.m
	10-12 W.m/ppm	Content ppm
Ag	0.224	3
Zn	0.290	-
O	0.356	200
Te	0.812	-
Zr	0.980	-
Pb	1.024	2
Cd	1.064	-
V	1.160	-
Ni	1.212	5
Sn	1.650	-
Mg	1.745	-
Al	2.220	-
Sb	2.900	3
Ge	3.790	-
Mn	4.760	-
Cr	4.900	-
Si	7.000	-
As	8.780	15
Fe	10.600	20
Co	10.700	-
P	14.300	-
S	18.600	3
Ti	21.600	-

Index	Alloys
100	CuZn40Pb3
95	CuZn36Pb3 CuSn8 à 11 Pb4 à 11
90	CuNi10Zn42Pb2 CuSn5Pb20 CuSn9Pb15
85	CuTe CuZn39Pb2
80	CuSn4Te CuPb1 CuNi14Zn42Mn2Pb2 CuNi12Zn29Pb2 CuZn9Sn3Pb5
75	CuS CuZn38Pb1 CuNi10Zn25Pb1.5 CuNi18Zn19Pb1
70	CuZn9Pb2 CuZn34Pb1 CuZn36Pb2 CuZn43Pb1 CuZn39FeMnSi
60	CuZn40Pb
50	CuZn40
35	CuZn37 CuZn22Al2 CuNi2Si CuSi3Mn1 CuZn28 à 33 CuZn28Sn1
30	CuNi10 à 25 Zn15 à 27
25	CuZn5 à 20
20	CuCr1 ; Cu-a1 ; Cu-b ; Cu-c1 ; CuAg ; CuCd ; CuCd1Sn ; CuZr ; CuBe2CoNi ; CuSn2 à 10P ; CuAl5 à 9 ; CuAl10Fe2à 5 Ni2 à 5 ; CuNi5 à 30 FeMn ; CuSn9 à 13P ; CuAl8 à 11 Fe1.5 à 5.5 Ni1 à 5.5

Summary