magnesium_bw.pdf

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05/11/2010 Prof. G. Ubertalli

Bibliography: Magnesium and Magnesium alloy - ASM Specialty

Handbook 1999

General Characteristics of Mg

Lattice structure is HEXC

The melting temperature is 650 C

The density is 1.738 Kg/m3

The elastic modulus is 42 GPa

Mg has a lower corrosion resistance

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It is flammable and explosive

Some alloys can increase strength if solute

heat treated and aged.

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First part Second part Third part Fourth part

The two main alloying

elements are indicated

in capital letter, they are

ordered considering the

weight (or alphabetic if

percentages are equal)

Indicates the quantity of

these elements

It distinguish alloys with

the same mains

alloying elements

percentage.

Heat treatment condition.

Two integer numbers

that indicate

percentage of the two

mains alloying elements

ordered as in the first

Alphabet letters in

progressive order

assigned when a

composition become

standard.

Letters and numbers

separated from the third

part by a dash.

ordered as in the first

part.

standard.

A-aluminium Numbers Alphabet letters except I and O.

F-as produced

O-annealed

H10 and H11- strain

hardened

H23, H24 e H26- strain

hardened and partially

annealed.

H4-solubilized

T5-artificially aged only

T6-solubilized and

artificially aged

B-bismuth

C-copper

D-cadmium

E-rare earths

F-iron

H-thorium

K-zirconium

L-lithium

M-manganese

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artificially aged

T8-solubilized, strain

hardened and artificially

aged.

M-manganese

N-nickel

P-lead

Q-silver

R-chromium

S-silicon

W-yttrium

Y-antimony

Z-zinc

Alloys for die castingAlloy (*) Chemical composition General characteristics

AZ91D Al 9%, Zn 0.7%, Mn 0.13% Is the most used alloy. Good strength at room

temperature, low viscosity good stability attemperature, low viscosity good stability at

atmospheric conditions, excellent sea water

corrosion resistance

AM60B Al 6%, Mn 0.13% Good strain rupture and toughness, excellent

corrosion resistance in sea water, good tensile

properties and yielding properties.

AS21X1 Al 1.7%, Si 1.1%, Mn 0.4% The best, creep resistant, die casting alloy,

good room temperature properties, it can be

used at high temperatures

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used at high temperatures

AS41XB Al 4.3%, Si 1%, Mn 0.35% Good creep resistance up to 175 C, good

room temperature properties, excellent

corrosion resistance in sea water, it can be

used at high temperatures.

(*) All characteristics in the as cast condition.

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Alloys for permanent and

sand casting

Alloying elements Alloy

Mg-Al-Mn AM100A

Mg-Al-Zn AZ63A, AZ81A, AZ91C,

AZ92A

Mg-Zn-Zr ZK51A, ZK61A

Mg-Rare Earths-Zn-Zr EZ33A, ZE41A

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Mg-Rare Eaths-Ag-Zr with or without Th QE22A, QH21A

Mg-Th-Zr with or without Zn HK31A, ZH62A, HZ32A

Mg-Zn-Cu ZC63A

The more used alloysAlloy H.T. Composition Characteristics

AM100A T4,T6 Al 10%, Mn 0.1% Die casting alloy weldable and stable

AZ91E T6 Al 8.7%, Zn 0.7%,Mn 0.13%

General purpose alloy, good strength, can be used till

175 C, stable, good corrosion resistance in sea water.

AZ92C T6 Al 9%, Zn 2%, General purpose alloy, good strength, can be used tillAZ92C T6 Al 9%, Zn 2%,Mn 0.1%

General purpose alloy, good strength, can be used till

175 C, stable.

EQ21A T6 Di* 2.1%, Ag 1.5%,Zr 0.7%

Heat treatment alloy, high yielding point till 250 C,

weldable.

EZ33A T5 R.H. 3.3%, Zn 2.7%,Zr 0.6%

Creep resistant till 250 C, low viscosity, weldable.

HZ32A T5 Th 3.3%, Zn 2.1%,Zr 0.7%

Creep resistant till 345 C, weldable.

QE22A T6 Ag 2.5%, Di* 2.1%,Zr 0.7%

Heat treatment alloy, high yielding point till 250 C,

weldable.

05/11/2010 Prof. G. Ubertalli

ZE41A T5 Zn 4.2%, R.H. 1.2%,Zr 0.7%

Low viscosity, weldable, high strength at room

temperature.

ZH62A T5 Zn 5.7%, Th 1.8%,Zr 0.7%

Low viscosity as the previous but more resistant,

weldable, pressure resistance.

ZK61A T6 Zn 5.7%, Zr 0.7% Excellent resistance at room temperature, high viscositybut its castings have good characteristics.

R.H. rare hearths

*neodymium and praseodymium

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Wrought alloys

Alloy H.T. Composition PropertiesAlloy H.T. Composition Properties

AZ10A F Al 1.2%, Zn 0.4%, Mn 0.2% r = 240 MPa, s = 145 MPa, A% = 10

AZ61A F Al 6%, Zn 1% r = 310 MPa, s = 230 MPa, A% = 16

Az80a T5 Al 8.5%, Zn 0.5%, r = 380 MPa, s = 275 MPa, A% = 7

ZK60A T5 Zn 5.5%, Zr 0.45%, r = 365 MPa, s = 305 MPa, A% = 11

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Mechanical Characteristics

Alloy UTS

[MPa]

y

[MPa]

Elongation % Notch toughness [J] at 24 C

AM100A - T61 275 150 1 -AM100A - T61 275 150 1 -

AZ91C - T6 290 132 6.3 7.96

AZ92A - T6 290 160 4 7.62

EQ21A - T6 235 195 2 -

EZ33A - T5 190 115 7.6 7.46

HZ32A - T5 185 90 4 -

QE22A - T6 280 213 4.4 23.5

ZE41A - T5 205 140 3.5 -

ZH62A - T5 275 192 5.7 15.02

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ZH62A - T5 275 192 5.7 15.02

ZK61A - T5 310 185 - -

AZ10A - F 240 145 10 -

AZ61A - F 310 230 16 -

Az80A - T5 380 275 7 -

ZK60A - T5 365 305 11 -

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Comparison among cast

technology

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Dimensional tolerance range allowed from different

casting technology. (Fig.2 45)

Comparison among cast technology

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Dimensional change, tolerance, discharge percentage

for two components in Mg-Al-Zn alloy. (Fig. 2 45)

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Mechanical characteristics at

different temperatures

Curve tensione-

deformazione per la

lega *** ****

parametrate in

funzione della

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funzione della

temperatura. (Fig. w 488)

Mechanical characteristics

at different deformation rate

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Applications

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Steering-wheel box Seat structure with

safety belt rolling up

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Aluminium and magnesium in an engine

block.

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