Non-ferrous metals and alloys

Introduction
Non-ferrous metals are all the known metals other than iron. Few of these metals are used in the pure state by engineers because of their relatively low strengths; two notable exceptions are copper and aluminium. Mostly they are used as the bases and alloying elements in both ferrous and non-ferrous alloys. Some non-ferrous metals are used for corrosion resistant coatings: for example, galvanized iron (zinc coated, low-carbon steel) and tinplate (tin coated, low-carbon steel).

It is not possible within the scope of this book to consider the composition and properties of the very large range of non-ferrous materials available. The following sections are, therefore, only an introduction to the composition and properties of some of the more widely used non-ferrous metals and alloys. For further information the wide range of British Standards relating to non-ferrous metals and alloys should be consulted, as should be the comprehensive manuals published by the metal manufacturers and their trade associations (e.g. Copper Development Association).

Only a limited number of non-ferrous alloys can be hardened by heat treatment. The majority can only be work-hardened by processing (e.g. cold rolling). Thus the conditionof the metal, as the result of processing, has an important effect upon its properties, as will be shown in the following sections.

Other notable non-ferrous alloys, which are not included in this section, but which should be considered are:

Magnesium alloys (Elektron): used for ultra-lightweight castings.

Nickel alloys (Nimonic): high-temperature-resistant alloys, used in jet engines and gas turbines.

Zinc-based alloys (Mazak): used for pressure die-casting alloys.

High copper content alloys

Silver copper

The addition of 0.1% silver to high-conductivity copper raises the annealing temperature by 150°C with minimal loss of conductivity. This avoids hard drawn copper components softening when conductors are being soldered to them.

Cadmium copper

Like silver, cadmium has little effect upon the conductivity of the copper. Cadmium strengthens, toughens, and raises the tempering temperature of copper. Cadmium copper is widely used for medium- and low-voltage overhead conductors, overhead telephone and telegraph wires, and the overhead conductors for electrified railways. In the annealed condition it has high flexibility and is used for aircraft wiring where its ability to withstand vibration without failing in fatigue is an important safety factor.

Chromium copper
A typical alloy contains 0.5% chromium. It is one of the few non-ferrous alloys which can be heat treated. Thus it can be manipulated and machined in the ductile condition and subsequently hardened and strengthened by heating to 500°C for approximately 2 h. It has a relatively low conductivity compared with silver copper and cadmium copper.

Tellurium copper
The addition of 0.5% tellurium makes the copper as machineable as free-cutting brass whilst retaining its high conductivity. It also improves the very high corrosion resistance of copper. Tellurium copper is widely used in electrical machines and switchgear in hostile environments such as mines, quarries and chemical plants. The addition of traces nickel and silicon makes tellurium copper heat treatable, but with some loss of conductivity.

Beryllium copper
This is used where mechanical rather than electrical properties are required. Beryllium copper is softened by heating it to 800°C and quenching it in water. In this condition it is soft and ductile and capable of being extensively cold worked. It can be hardened by reheating to 300–320°C for upwards of 2 h. The resulting mechanical properties will depend on the extent of the processing (cold working) received prior to reheating. Beryllium copper is widely used for instrument springs, flexible metal bellows and corrugated diaphragms for aneroid barometers and altimeters, and for the Bourdon tubes in pressure gauges. Hand tools made from beryllium copper are almost as strong as those made from steel, but will not strike sparks from other metals or from flint stones. Thus tools made from beryllium copper alloy are used where there is a high risk of explosion (e.g. mines, oil refineries, oil rigs and chemical plants).

Wrought copper and copper alloys: condition code

O Material in the annealed condition (soft)

M Material in the ‘as-manufactured’ condition

¼ H Material with quarter-hard temper (due to cold working)

½ H Material with half-hard temper

H Material with fully hard temper

EH Material with extra-hard temper

SH Material with spring-hard temper

ESH Material with extra-spring-hard temper.

The above are listed in order of ascending hardness.

Materials which have acquired a hard temper due to cold working can have their hardness reduced and their ductility increased by heat treatment (e.g. annealing or solution treatment).

Chemical symbols used in the following tables:

Al aluminium Co cobalt Ni nickel Si silicon

Ar arsenic Cr chromium P phosphorus Sn tin

Be berylliumCu copper Pb lead Te tellerium

Bi bismuth Fe Iron S sulphur Ti titanium

C calcium Mg magnesium Sb antimony Zn zinc

Cd cadmiumMn manganese Se selenium Zr zirconium

British Standards relating copper and copper alloys
British Standard BS 2874 Copper and copper alloy rods and sections (chemical composition and mechanical properties) relating to copper and copper alloys is now obsolescent and should not be specified for new designs although the materials listed within this Standard will continue to be available and be used for some time to come.

The replacement standards are as follows.

BS EN 12163: 1998 – Copper and copper alloys (rod for general purposes).
BS EN 12167: 1998 – Copper and copper alloys for profiles and rectangular bar for general purposes.
BS EN 1652: 1997 – Copper and copper alloys for plate, sheet and circles for general purposes.
BS EN 1653: 1998 – Copper and copper alloys for plate sheet and circles for boilers, pressure vessels and hot water storage units.
BS EN 1982: 1998 – Copper and copper alloys for ingots and casting.

The following copper and copper alloy materials listed in Sections below inclusive are for guidance only.

Copper and copper alloy rods and sections

Chemical composition, tolerance group and mechanical properties of coppers

Note: For essential alloying elements, limits are in bold type. Unless otherwise stated, figures in the total impurities column include those that are not in bold type. Unless otherwiseindicated, all single limits are maxima.

Chemical composition, tolerance group and mechanical properties of alloyed coppers (continued)

Wrought copper and copper alloys

Chemical composition and mechanical properties of brasses

Copper sheet, strip and foil

These properties are common to C101, C102, C103, C104 and C106 as listed above

Condition	Thickness		Tensile strength		Elongation on 50mm (min.)(%)	Hardness HV	Bend Test
	Over (mm)	Up to and including (mm)	Up to and including 450mm wide (min.) (N/mm²)	Over 450mm wide (min.) (N/mm²)			Transverse bend		Longitudinal bend
	Over (mm)	Up to and including (mm)	Up to and including 450mm wide (min.) (N/mm²)	Over 450mm wide (min.) (N/mm²)			Angle degrees	Radius	Angle degrees	Radius
O	0.5	10.0	210	210	35	55 (max.)	180	Close	180	Close
M	3.0	10.0	210	210	35	65 (max.)	180	Close	180	Close
½ H	0.5 2.0 0.5	2.0 10.0 2.0	240 240 310	240 240 280	10 15 –	70/95 70/95 90 min.	180 180 90	t t t	180 180 90	t t t
H	2.0	10.0	290	280	–	–	–	–	–	–

Based on BS 2870:1980, which should be consulted for full information.

For essential alloying elements, limits are in bold type. Unless otherwise stated, figures in total impurities column include those in lighter type. Unless otherwise indicated, all limits are maxima.

Note: N/mm²= MPa.

Brass sheet, strip and foil: binary alloys of copper and zinc
For designations CZ125, CZ101, CZ102, CZ103

Designation	Material	Copper (%)	Lead (%)	Iron (%)	Zinc (%)	Total impurities (%)	Condition	Thickness		Tensile strength
Designation	Material	Copper (%)	Lead (%)	Iron (%)	Zinc (%)	Total impurities (%)	Condition	Over (mm)	Up to and including (mm)	Up to and including 450mm wide (min.) (N/mm²)	Over 450mm wide (min.) (N//mm²)
CZ125	Cap copper	95.0/98.0	0.02	0.05	Rem.	0.025	O	–	10	–	–
C2101	90/10 Brass	89.0/91.0	0.05	0.10	Rem.	0.40	O ½ H ½ H O	– – 3.5 –	10.0 3.5 10.0 10.0	245 310 350	245 380 325
CZ102	85/15 Brass	84.0/86.0	0.05	0.10	Rem.	0.40	O ½ H ½ H H	– – 3.5 –	10.0 3.5 10.0 10.0	245 325 370	245 295 340
CZ103	80/20 Brass	79.0/81.0	0.05	0.10	Rem.	0.40	O ½ H ½ H H	– – 3.5 –	10.0 3.5 10.0 10.0	265 340 400	265 310 370

Designation	Elongation on 50mm min. (%)	Vickers hardness (H_V)				Bend Test				Compiles with or falls within ISO
		Up to and including 450mm wide		Over 450mm wide		Transverse bend		Longitudinal bend
		min.	max.	min.	max.	Angle degrees	Radius	Angle degrees	Radius
CZ125	–	–	75	–	75	180	Close	180	Close	–
CZ101	35 7 3	– 95 110	75 – –	– 85 100	75 – –	180 180] 180] 90	Close Close t 2t	180 180 180 90	Close Close t t	ISO 426/1 Cu Zn 10
CZ102	35 7 3	– 95 110	75 – –	– 85 100	75 – –	180 180] 180] 90	Close Close t 2t	180 180 180 90	Close Close t t	ISO 426/1 Cu Zn 15
CZ103	40 10 5	– 95 110	80 – –	– 85 100	80 – –	180 180] 180] 90	Close Close t 2t	180 180 180 90	Close Close t t	ISO 426/1 Cu Zn 20

Designation

Material

Copper

(%)

Lead

(%)

Iron

(%)

Zinc

(%)

Total impurities

(%)

Condition

Thickness

Tensile strength

Over

(mm)

Up to and including

(mm)

Up to and including 450mm wide (min.)

(N/mm²)

Over 450mm wide

(min.)

(N/mm²)

CZ106

70/30

Cartridge

Brass

68.5/71.5

0.05

Rem.

0.30

¼ H

½ H

–

3.5

–

10.0

3.5

10.0

280

325

350

415

280

325

340

385

CZ107

2/1 brass

64.0/67.0

0.10

Rem.

0.40

¼ H

½ H

–

3.5

–

10.0

3.5

10.0

280

340

385

460

525

280

325

350

415

–

CZ108

Common

brass

62.0/65.0

0.30

0.20

Rem.

0.50

(excluding lead)

¼ H

½ H

–

3.5

–

10.0

3.5

10.0

280

340

358

460

525

280

325

350

415

–