Magnesium Casting Alloys

General Characteristics

Alloy Characteristics
AZ91D High purity alloy.  The most commonly used alloy for die castings. It has excellent castability and high mechanical strength.  Good bearing properties.  (Non-high purity versions are AZ91A & AZ91B.)
AZ91E High purity alloy commonly used for sand castings.  It has excellent mechanical strength.  Can be welded when sand or permanent mold cast.  Good bearing properties.  (Non-high purity version is AZ91C.)
AZ81A Commonly used for sand castings.   Good strength, ductility, toughness both in the as-cast and heat treated conditions.  Can be weldedwhen sand or permanent mold cast.  Good bearing properties.
AM60B High purity alloy.  Good ductility nad toughness, as well as cold workability.  Typical uses are bow handles and wheels.  (Non-high purity version is AM60A.)
AS41A Excellent creep resistance up to 300F.
AS21 Excellent creep resistance up to 350F.


Composition Specifications

ASTM Ingot Composition Specifications (B-93)
Alloy %Al %Zn %Mn (min.) %Si (max.) %Cu (max.) %Ni (max.) %Fe (max.) % Other each1 % Other total (max.) Color Code
AZ92A 8.5-9.5 1.7-2.3 0.13 0.20 0.20 0.01 NS NS 0.30 Orange
AZ91A
AZ91B
AZ91C
AZ91D
AZ91E
8.5-9.5
8.5-9.5
8.3-9.2
8.5-9.5
8.3-9.2
0.45-0.9
0.45-0.9
0.45-0.9
0.45-0.9
0.45-0.9
0.15
0.15
0.15-0.50
0.17
0.17-0.50
0.20
0.20
0.20
0.05
0.20
0.08
0.25
0.08
0.015
0.015
0.01
0.01

0.01
0.001
0.0010
NS
NS
NS
0.004
0.005
NS
NS
NS
0.01
0.01
0.30
0.30
0.30
NS
0.03
Blue
Blue & Yellow
Brown
Yellow
AZ81A 7.2-8.0 0.5-0.9 0.15-0.50 0.20 0.08 0.01 NS NS 0.30 Blue & Red
AM60A
AM60B
5.7-6.3
5.7-6.3
0.20 max.
0.20 max.
0.15
0.27
0.20
0.05
0.25
0.008
0.01
0.001
NS
0.004
NS 0.30
NS
Green & White
White
AS41A 3.7-4.8 0.10 max. 0.22-0.48 0.60-1.4 0.04 0.01 NS NS 0.30 Red
AS212 1.9-2.5 0.15-0.20 0.35 0.70-1.2 0.04 0.002 NS NS 0.30  
ASTM Part Composition Specifications (B-94)
AZ91D 8.3-9.7 0.35-1.0 0.15 0.10 0.030 0.002 0.0053 0.02 NS Yellow
AM60B 5.5-6.5 0.22 max. 0.25 0.10 0.010 0.002 0.0053 0.02 NS White
1Metallic impurities.
2Hydro Magnesium specification.
3For alloys AZ91D and AM60B, of iron content exceeds 0.005%, the the permissible iron to manganese
ratios will not exceed 0.032 and 0.021 respectively.
NS Not Specified.
Die casting alloys contain about 8ppm (g/ton) Beryllium to reduce oxidation in the molten state.
High purity versions of other casting alloys are available on special request.


Typical Physical Properties

Density 0.066 lb/in.3 @ 68F 1.8 g/cc @ 20C
Thermal Expansion 15.2x10-6 in/in/F @ 68-392F 27x10-6 cm/cm/C @ 20-100C
Thermal Conductivity 27-34 BTU ft/(ft2 hr F) @ 68-572F 50-84 Watts/(C m) @ 200-300C
Modulus of Elasticity 6.5x106 psi 40-45 kN/mm2
Electrical Resistivity 25-43x10-6 Ohmin @ 68F 10-17x10-6 Ohmcm @ 20C
Latent Heat of Fusion 150 BTU/lb (9.9 BTU/in3) 0.37 MJ/kg
Specific Heat Capacity 0.240-0.250 BTU/(Flb.) @ 68F 1005-10047 J/Ckg) @ 25C
decreasing with decreasing alloy content.


Mechanical Properties

Alloy Usage Temper1 Tensile Strength KSI Yield Strength
0.2KSI
Elongation
%
Brinell Hardness
HB-5/250
Fatigue Strength
KSI
2
Specific Damping Capacity3
AZ92A Sand Casting -F
-T4
-T5
-T6
(23)
(34)
(23)
(34)
(11)
(11)
(12)
(18)
NS
(6)
NS
(1)
65
63
69
81
NS
NS
NS
NS
 
AZ91C & AZ91E Sand Casting -F
-T4
-T5
-T6
(23)
(34)
(23)
(34)
(11)
(11)
(12)
(16)
NS
(7)
(2)
(3)
60
55
62
70
10-13*
12-15*

12-15*
 
AZ91C & AZ91E Permanent Mold Casting -F
-T4
-T5
-T6
(23)
(34)
(23)
(34)
(11)
(11)
(12)
(16)
NS
(7)
(2)
(3)
55-70*
55-70*

60-90*
10-13*
12-15*

12-15*
 
AZ91A
AZ91B
AZ91D
Die Casting -F
-F
-F
34
34
34
23
23
23
3
3
3
63
63
63
144
144
144
25%
25%
25%
AZ81A Sand Casting

Permanent Mold Casting

-F
-T4

-F
-T4

23-32(19)*
(34)

23-32(19)*
34

13-16(12)*
(11)

13-16(12)*
11

2-6(1)*
(7)

2-6(1)*
7

50-65*
55

50-65*
50-65*

10-13*
12-15*

10-13*
12-15*

 
AM60A* & AM60B* Sand Casting -F
-T4
26-35(20)*
28-36(22)*
12-16(12)*
13-16(13)*
8-12(4)*
8-15(6)*
50-65(50)*
50-65(50)*
10-13*
10-13*
 
AM60A & AM60B Die Casting -F 32 19 8 55-70* 7-104* 45%
AS41A Die Casting -F 31 20 6 60-90* 7-104* 40%
AS21* Die Casting -F 25* 16* 4* 63* NS 60%
Numbers in parenthesis are minimum values which can be used in calculating stresses in castings with wall thickness up to 0.600 in.
1Temper:  F = As Cast.  T4 = Solution Treated.  T5 = Artificially Aged.  T6 = Solution Treated & Artificially Aged.
2Rotating beam fatigue test unless otherwise noted.  Stress corresponding to a lifetime of 50x106 cycles.
3Measured at 5000 psi.  Bureau of Mines Data.
4Reverse bending fatigue test (RR Moore).  Stress corresponding to a lifetime of 50x106 cycles.
All data were obtained directly from ASTM Specs unless otherwise noted.
*Hydro Magnesium Data
NS - Not Specified.


Return

8582 Moeller Dr.
Harbor Springs, MI 49740
Phone: (231) 347-6834
Fax: (231)439-9766
email: [email protected]