ZK40A (ZK40A-T5, M16400) Magnesium
ZK40A magnesium is a magnesium alloy. Cited properties are appropriate for the T5 temper. To achieve this temper, the metal is artificially aged until it meets standard mechanical property requirements. ZK40A is the ASTM designation for this material. M16400 is the UNS number.
It has a moderately high base cost among magnesium alloys. In addition, it has a fairly high electrical conductivity and a moderately high thermal conductivity.
The graph bars on the material properties cards below compare ZK40A magnesium to other magnesium alloys (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
45 GPa 6.5 x 106 psi
Elongation at Break
4.2 %
Fatigue Strength
190 MPa 28 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
17 GPa 2.5 x 106 psi
Shear Strength
160 MPa 24 x 103 psi
Tensile Strength: Ultimate (UTS)
280 MPa 41 x 103 psi
Tensile Strength: Yield (Proof)
260 MPa 38 x 103 psi
Thermal Properties
Latent Heat of Fusion
340 J/g
Maximum Temperature: Mechanical
120 °C 250 °F
Melting Completion (Liquidus)
600 °C 1110 °F
Melting Onset (Solidus)
540 °C 1010 °F
Specific Heat Capacity
970 J/kg-K 0.23 BTU/lb-°F
Thermal Conductivity
110 W/m-K 64 BTU/h-ft-°F
Thermal Expansion
26 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
27 % IACS
Electrical Conductivity: Equal Weight (Specific)
130 % IACS
Otherwise Unclassified Properties
Base Metal Price
13 % relative
Density
1.8 g/cm3 110 lb/ft3
Embodied Carbon
24 kg CO2/kg material
Embodied Energy
160 MJ/kg 71 x 103 BTU/lb
Embodied Water
950 L/kg 110 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
12 MJ/m3
Resilience: Unit (Modulus of Resilience)
740 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
65 points
Strength to Weight: Axial
43 points
Strength to Weight: Bending
53 points
Thermal Diffusivity
62 mm2/s
Thermal Shock Resistance
17 points
Alloy Composition
| Mg | 94.2 to 96.1 | |
| Zn | 3.5 to 4.5 | |
| Zr | 0.45 to 1.0 | |
| res. | 0 to 0.3 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B107: Standard Specification for Magnesium-Alloy Extruded Bars, Rods, Profiles, Tubes, and Wire
Essential Readings in Magnesium Technology, Suveen N. Mathaudhu et al. (editors), 2014
Environmental Degradation of Advanced and Traditional Engineering Materials, Lloyd H. Hihara et al., 2014.
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015