ZAMAK Multi-slide die casting

What is die casting?

Die casting is the process in which molten metal is poured or forced into steel mold. Die casting is the most efficient process for high volume precision parts producing the best tolerance & rapid production. The mold known as tools or dies which are created using steel and they are specially designed for each project. This allows each component to be created with a accuracy and repeat ability. Aluminum, Zinc, and Magnesium are the most commonly used die casting alloys.

Die casting is a cost effective process for components requiring high volumes and complex geometries. Die casting is a net-shape process, and cost savings can be achieved by eliminating secondary machining and assembly operations required by other processes.

Comparison of Multi-Slide Die casting & Conventional Multi-slide Die-casting :

PML Multi-Slide 
Die Casting Machine
Conventional
Die Casting Machine
    No. of slides 2-6 2
    Sprue requirement No Yes
    Precision level High(0.005mm) Normal
    Complex casting Easy Difficult
    Production cycle Fast(up to 45shots/min) Slow
    Surface finish High High
    Material usage Low High
    Die Change Easy(15mins) Difficult
    Secondary operations Reduced/Eliminated Required
    Output High Low

Advantages of using Multi-slide die-casting:

  • Die casting is an efficient, high volume economical process offering a broader range of shapes and components than any other manufacturing technique
  • High-speed production.
  • Dimensional accuracy, stability and surface finish
  • Strength , weight and dimension stability
  • Multiple finishing techniques
  • Simplified Assembly.
  • Thin wall die casting.

Zamak Multi-slide die-casting: let's explain it

The ingots of zamak are melted in an furnace at about 420°C in the machine and the alloy is injected into a mold. Thanks to the high fluidity and low melting point, zamak allows to obtain pieces with very low tolerance limits and, at the same time, complex and articulated shapes.


The use of the ZAMAK in the Multi-slide die-casting has several advantages:

  • Resistance to shocks, wear and corrosion -

    The articles produced from die-casting zamak offer greater impact resistance and wear with respect to the articles produced with other alloys, or plastic, having zamak a hardness comparable to that of cast iron or brass. In addition, the corrosion resistance, in it self very good, is further increased if the items undergo a process of galvanic finishing such as zinc plating, chrome plating, nickel plating, satin finishing.

  • Machineability -

    Fast, trouble-free machining characteristics of zinc materials minimize tool wear and machining costs which is a major advantage of zinc alloys over competitive materials.

  • Versatility in finishing the articles -

    The high precision of the articles die-castes in zamak simplifies the process of painting, varnishing, or polishing and plating, and even silver or gold plating

  • High accuracy of the castings -

    The characteristic ductility of the zamak, along with its good strength, allow to have a great flexibility in the design of small parts and details. Compared to other alloys used for die casting, such as aluminium and magnesium, with zinc alloys it is possible to obtain closer tolerances and better finishes in die casted articles. Press Fin Metal is able to produce articles in zamak with a weight varying from a dozen of grams to more than two kilograms;

  • Production time savings -

    This process combined with the relatively low casting temperature needed for zinc alloys allows exceptionally high production rates. For medium sized zinc components, 400 to 1000 shots per hour are common. By comparison, typical shot speed ranges for medium sized aluminum, magnesium and plastic components from 100 to 250, 200 to 300 and 100 to 300, respectively.

  • Energy savings -

    For an equal number of same size die castings, aluminum will use at least 50% more energy than zinc, while magnesium will need at least 15% more energy per casting than zinc. This is in addition to the high energy requirements needed to produce the aluminum and magnesium.

  • Production cycle with low impact on the environment -

    During the die-casting process, the ZAMAK, being an alloy of zinc, does not disperse in the air or in the environment any substances that cause pollution. Furthermore, since the melting point of the zamak is at only about 410/420° C, it allows a considerable energy saving;

  • Recycleability -

    All items made with die-caste zamak are recyclable. Zinc alloy comfortably confirm to the requirements of the end of life vehicle(ELV), Restriction of hazardous substance(RoHS) and waste electrical and electronic equipment(WEEE) legislation

Technical specification of ZAMAK alloys:

Composition of Zamak Ingot with industry standards ASTM
Alloying elements
Unit
Zamak 2 Zamak 3 Zamak 5
Limit Limit Limit
Ingot Casting Ingot Casting Ingot Casting
Al % 3.9-4.3 3.7-4.3 3.9-4.3 3.7-4.3 3.9-4.3 3.7-4.3
Mg % 0.005-0.020 0.02-0.06 0.03-0.06 0.02-0.06 0.03-0.06 0.02-0.06
Cu % 2.6-2.9 2.6-3.3 0.10max 0.1max 0.7-1.1 0.7-1.2
Fe (max) % 0.035 0.050 0.035 0.050 0.035 0.050
Pb (max) % 0.004 0.005 0.004 0.005 0.004 0.005
Cd (max) % 0.003 0.004 0.003 0.004 0.003 0.004
Sn (max) % 0.0015 0.002 0.0015 0.002 0.0015 0.002
Ni (other) 10 % - - - - - -
Zn % Bal Bal Bal Bal Bal Bal
Composition of Zamak Ingot with industry standards EN
Alloying elements Unit
Zamak 2 Zamak 3 Zamak 5
Limit Limit Limit
Ingot Casting Ingot Casting Ingot Casting
Al % 3.8-4.2 3.7-4.3 3.8-4.2 3.7-4.3 3.8-4.2 3.7-4.3
Mg % 0.035-0.06 0.025-0.06 0.035-0.06 0.025-0.06 0.035-0.06 0.025-0.06
Cu % 2.7-3.3 2.7-3.3 0.03max 0.1max 0.7-1.1 0.7-1.2
Fe (max) % 0.02 0.050 0.02 0.050 0.02 0.050
Pb (max) % 0.003 0.005 0.003 0.005 0.003 0.005
Cd (max) % 0.003 0.005 0.003 0.005 0.003 0.005
Sn (max) % 0.001 0.002 0.001 0.002 0.001 0.002
Ni (max)
% 0.001 0.02 0.001 0.02 0.001 0.02
Si (max) % 0.02 0.03 0.02 0.03 0.02 0.03
Zn % Bal Bal Bal Bal Bal Bal
Mechanical properties of ZAMAK
Property Unit Zamak 2 Zamak 3 Zamak 5
Value Value Value Value
Ultimate Tensile Strength MPa (1) (5) 397 315 331
Yield Strength MPa (1) (5) 360 276 295
Elongation Break
% 5.99 7.73 3.43
e at UTS - 2 2 3
e at rupture - 5 7 3
Modulus of Elasticity (Young) GPa (1)(4)(5) 84 84 84
Shear Strength MPa 317 214 262
Hardness Brinell (1) 130 97 114
IZOD Notched 20°C J/cm² - 2 2
Charpy Unnotched 20°C J/cm² 116 96 116
Charpy Notched 20°C J/cm² 9 - 4
5x108 cycles - 59 48 57
1x107 cycles - 104 81 86
0.2% Offset MPa 257 274 199
2% Offset MPa 379 373 266
Physical properties of ZAMAK
Property Unit Zamak 2 Zamak 3 Zamak 5
Value Value Value Value
Density g/cm³
at RT
6.8 6.66 6.76
Melting Range °C 379°-390° 381°-387° 380°-386°
Electrical Conductivity % IACS 25 27 27
Thermal Conductivity W/m.°C 104 113 108
Coefficient of Thermal Expansion ppm/°C 27 27 27
Heat Capacity
J/g.°C 0.422 0.391 0.398
at 100°C °C 446 451 422
at 20°C °C 422 391 398
Coefficient of friction 0 0 0 0
Die Shrinkage mm/mm 0.007 0.007 0.007

NOTE: Reference from International Zinc Association.


Benefits of Multi slide die casting :

  • Net shape die casting the first time.
  • Eliminates secondary operations like machining, surface finish trimming.
  • Minimum part-to-part variation compared to conventional multi-cavity dies.
  • Compact tooling that is less prone to parting-line variation and its negative effect on the finished part’s dimensional tolerances.
  • High precision of parts as +/- 0.001" or .025mm

Zamak Multi-slide die casting assembly process :


Zamak die casting assembly process