ZL8 is a hot chamber pressure die casting alloy

ZL8 conforms to EN 1774 1997 Ingot Specification, was developed to meet specific applications and is one of the family of versatile high-grade alloys we manufacture in.  ZL8 is a direct replacement for ZA8 and can also be used to make sand and permanent mould castings.

Application

ZL8 is designed to extend the application range of Zinc alloy die castings. In the past Zinc alloys were considered unsuitable for applications where moderate stress was anticipated at elevated temperatures. ZL8 offers the best creep resistance of all hot chamber diecasting alloys and it should be specified for structural or stressed applications for which other Zinc alloys would be unsuitable. Although it is the strongest of the hot chamber alloys, it still possesses all the properties associated with Zinc diecasting alloys. The combination of high strength, excellent dimensional stability, good surface finish and definition make it ideal for visible stressed parts which are subject to elevated temperature during service. The increased levels of Aluminium have no significant effects on the finishing of castings made from this alloy. Finishes suitable for traditional Zinc pressure die casting alloys can be applied to castings made from ZL8 alloys with excellent results. Typical applications for this alloy are under bonnet automotive parts, stressed parts for hazardous or mining environments, stressed electrical or computer parts.

This specification has been taken from EN 1774 – Zinc and Zinc Alloys – Alloys for Foundry Purposes – Ingot and Liquid.

The Noranda Research Centre, Quebec, Canada, developed the ZL8 alloy and carried out the detailed characterization of the material properties pertaining to this alloy.

MIN MAX
Aluminimum 8.2% 8.8%
Copper 0.9% 1.3
Magnesium 0.02% 0.03%
Zinc REMAINDER
Impurities
Iron - 0.035%
Lead - 0.005%
Cadmium - 0.005%
Tin - 0.002%
Nickel - 0.001%
Silicon - 0.035%
Pressure Die Casting
Casting Temperature °C 415-435
Freezing Range °C 375-404
Specific Heat J/GK 0.4354
- (0.104)
Solidification

Shrinkage

Cm/m 1.10
(in/ft) (0.132)
Casting Shrinkage Mm/mm 0.007
(in/in) (0.007)
Thermal Conductivity at 18 °c W/m°C 114.7
BTU/FT/hrFT²/P 66.3
Thermal Expansion Linear

 per °c

- 23.3X10₆
Pressure Diecasting
Electrical Conductivity

At 20°C

%age

IACS

27.7
Specific Gravity - 6.3
Density Kg/m₃ 6300
(ib/in₃) (0.227)
Tensile Strength at 20°c N/mm² 374
(ib/in²) (54200)
Elongation at 20°C %in 2in 6-10%
Impact strength at 20°C

(unnotched samples)

J

(ft.obf)

42

(31)

Hardness BHN 103

Figures relate to material in casting form. Properties vary for different processes. Further data available on request.