Smithells Light Metals Handbook Part 4 docx

Table 3.7 MAGNESIUM AND MAGNESIUM ALLOYS WROUGHT TYPICAL MECHANICAL PROPERTIES AT ROOM TEMPERATURE Zn 0.5 Mn 0.3... 44 Smithells Light Metals HandbookTable 3.9 MAGNESIUM AND MAGNESIUM AL

Table 3.7 MAGNESIUM AND MAGNESIUM ALLOYS (WROUGHT) TYPICAL MECHANICAL PROPERTIES AT ROOM TEMPERATURE

Zn 0.5

Mn 0.3

(1 in diam.)

Zn 5.5 Bars and sections

Mg Zn Cu Mn Zn 6.5 Bars and sections

Mn 0.8

5111

Zr 0.6

(Creep resistant) Mn 0.75

Mn 1.2

Nuclear alloys: Two wrought magnesium alloys (Magnox AL80; Mg0.75Al-0.005 Be and MN70; Mg0.75 Mn) of interest only for their nuclear and high-temperature properties have room-temperature tensile properties similar to those of AM503

ŁIt is usual to add 0.2 0.4% Mn to alloys containing aluminium to improve corrosion resistance M D As manufactured O D Fully annealed TE D Precipitation treated

ŁŁThorium-containing alloys are being replaced by alternative Mg alloys

Table 3.8 MAGNESIUM AND MAGNESIUM ALLOYS (CAST) TYPICAL MECHANICAL PROPERTIES AT ROOM TEMPERATURE

Zr 0.7

RE 1.2

Zr 0.7

RE 2.5

Zr 0.7

(Creep resistant) Zn 2.2

to 250°C) Zr 0.7

(Creep resistant Zn 2.2

to 350°C) Zr 0.7

Th 1.8

Zr 0.7

Zr 0.7

Zr 0.6

RE 2.0‡

Zr 0.6

Zr 0.6

Cu 0.07

RE 1.0‡

Th 1.0

Zr 0.7 RE()3.4

Zr 0.6

RE()3.0

Zr 0.6

Cu 2.7

Mn 0.5

ŁIt is usual to add 0.2 0.4% Mn to alloys containing aluminium to improve corrosion resistance RE D Cerium mischmetal containing approx 50% cerium RE./ D Neodymium plus Heavy Rare Earth metals

‡Fractionated rare earth metals: MSR-A contains 1.7%; MSR-B contains 2.5%

§Solution heat treated in an atmosphere of hydrogen

AC D Sand cast TE D Precipitation heat treated

TB D Solution heat treated TF D Fully heat treated

ŁŁThorium-containing alloys are being replaced by alternative Mg alloys

44 Smithells Light Metals Handbook

Table 3.9 MAGNESIUM AND MAGNESIUM ALLOYS (excluding high temperature alloys for which see table 3.10) TYPICAL TENSILE PROPERTIES AT ELEVATED TEMPERATURES

‘Short-time’ tension†

Nominal Test Young’s 0.2%

compositionŁ Form and temp modulus proof stress UTS Elong Material % condition °C GPa MPa MPa %

Mechanical properties of light metals and alloys 45

Table 3.9 (continued )

‘Short-time’ tension†

Nominal Test Young’s 0.2%

compositionŁ Form and temp modulus proof stress UTS Elong Material % condition °C GPa MPa MPa %

ŁIt is usual to add 0.2 0.4% Mn to alloys containing aluminium to improve corrosion resistance

†In accordance with BS1094: 1943; 1 h at temperature and strain rate 0.1 0.25 in in 1min1

‡Tested according to BS4A4 RE D Cerium mischmetal containing approx 50% Ce RE(D) D Neodymium enriched mischmetal RE./ D Neodymium plus Heavy Rare Earth metals

ŁŁThorium-containing alloys are being replaced by alternative Mg alloys

46 Smithells Light Metals Handbook

Table 3.10 HIGH TEMPERATURE MAGNESIUM ALLOYS TENSILE PROPERTIES AT ELEVATED TEMPERATURE

‘Short-time’ tension†

Nominal Test Young’s 0.2%

compositionŁ Form and temp modulus proof stress UTS Elong Material % condition °C GPa MPa MPa %

(EQ21)

Mg Ag RE(D) Ag 2.5 Sand cast High strength cast alloys with good elevated temperature













































properties for which see Table 3.9

(QH21)

ŁIt is usual to add 0.2 0.4% Mn to alloys containing aluminium to improve corrosion resistance

†In accordance with BS 1094: 1943; 1 h at temperature; strain rate 0.1 0.25 in in 1min 1

RE D Cerium mischmetal containing approx 50% Ce RE(D) D neodymium-enriched mischmetal

RE./ D Neodymium plus Heavy Rare Earths

ŁŁThorium containing alloys are being replaced by alternative Mg alloys

Mechanical properties of light metals and alloys 47

Table 3.11 HIGH-TEMPERATURE MAGNESIUM ALLOYS LONG-TERM CREEP RESISTANCE

Stress to produce specified creep strains% Nominal

composition Form and Temp Time† 0.05 0.1 0.2 0.5 1.0

Material % Condition °C h MPa MPa MPa MPa MPa

(ZRE1)

(RZ5)

(ZT1)

(TZ6)

48 Smithells Light Metals Handbook

Table 3.11 (continued )

Stress to produce specified creep strains% Nominal

composition Form and Temp Time† 0.05 0.1 0.2 0.5 1.0

Material % Condition °C h MPa MPa MPa MPa MPa

(EQ21)

(QH21)

ŁTotal strains

†4 6 h heating to test temperature followed by 16 h soaking at test temperature

RE D Cerium mischmetal containing approx 50% Ce

RE(D) D Neodymium-enriched mischmetal

RE./ D Neodymium plus Heavy Rare Earth metals

ŁŁThorium-containing alloys are being replaced by alternative Mg alloys

Mechanical properties of light metals and alloys 49

Table 3.12 HIGH-TEMPERATURE MAGNESIUM ALLOYS SHORT-TERM CREEP RESISTANCE

Stress to produce specified creep strains%

composition Form and Temp Time† 0.05 1.0 2.0 5.0 10.0 fracture Material % condition °C s MPa MPa MPa MPa MPa MPa

(ZRE1)

(RZ5)

(ZTY)

(ZT1)

(TZ6)

†1 h heating to test temperature followed by 1 h soaking at test temperature

RE D cerium mischmetal containing approx 50% Ce

Table 3.13 MAGNESIUM AND MAGNESIUM ALLOYS FATIGUE AND IMPACT STRENGTHS

Fatigue strength† at specified cycles Impact strength§ for single blow fracture

(AZM)

treated

(ZW3)

(Z5Z)

(ZE63)

(QH21)

(TZ6)

continued overleaf

Table 3.13 (continued )

Fatigue strength† at specified cycles Impact strength§ for single blow fracture

ŁIt is usual to add 0.2 0.4% Mn to alloys containing aluminium to improve corrosion resistance § Hounsfield balanced impact test, notched bar values are equivalent to Izod values

ŁŁSolution heat treated in an atmosphere of hydrogen RE(D) D Neodymium enriched mischmetal

† Wohler rotating beam tests at 2960 c.p.m ŁŁŁThorium-containing alloys are being replaced by alternative Mg alloys

N D Notched Semi-circular notch of 0.12 cm (0.047 in) radius Stress concentration factor 1.8

Mechanical properties of light metals and alloys 53

Table 3.14 HEAT TREATMENT OF MAGNESIUM ALLOY CASTINGS

Heat treatment conditions for magnesium sand castings can be varied depending on the particular components and specific properties required The following are examples of the conditions used for each alloy which will give properties meeting current national and international specifications

NominalŁ composition Time Temperature

Air cool

54 Smithells Light Metals Handbook

Table 3.14 (continued )

NominalŁ

composition Time Temperature

Note:- Above 350°C, furnace atmospheres must be inhibited to prevent oxidation of magnesium alloys This can be achieved either by:

(i) adding 1/2 1%SO1gas to the furnace atmosphere; or

(ii) carrying out the heat treatment in an atmosphere of 100% dry CO2

ŁIt is usual to add 0.2 0.4% Mn to alloys containing aluminium to improve corrosion resistance

RE D Cerium mischmetal containing approximately 50% cerium TB D Solution heat treated

RE(D) D Neodymium-enriched mischmetal TE D Precipitation heat treated

RE./ D Neodymium plus Heavy Rare Earth metals TF D Fully heat treated

†Thorium-containing alloys are being replaced by alternative Mg alloys

Mechanical properties at subnormal temperatures

At temperatures down to 200°C tensile properties have approximately linear temperature coeffi-cients: proof stress and UTS increase by 0.1 0.2% of the RT value per°C fall in temperature, and elongation falls at the same rate: modulus of elasticity rises approximately 19 MPa (2800 lbf in 2) per°C over the range 0°to 100°C No brittle-ductile transitions have been found.

Tests at 70°C have suggested that the magnesium-zinc-zirconium alloys show the best retention

of ductility and notched impact resistance at this temperature.