Diecasting & Thixomolding ®
DIECASTING
The two main methods of die- casting are Cold chamber and Hot chamber.
During casting process molten metal is injected under high pressure into a steel mold (die) and this is different with the two methods:

  • Cold chamber means that the liquid metal is passed into the cold casting chamber by hand or by means of a proportioning furnace or a scooping tool See the Cold chamber movie

  • Hot chamber means that the molten metal is transported directly to the die via the heated (hot) casting settings (casting container, nozzle). The flowing metal hardly comes into contact with air. The melting and warming furnaces are directly adjoining parts of the casting machine See the Hot chamber movie

The castability of magnesium using die-casting processes is excellent and these are the standard alloys.

Alloy: AZ91D

  • The most common alloy used in high pressure die casting
  • This alloy offers good strenght/weight ratio and excellent castability
Alloy: AM50 & AM60B
  • For safety components in the automotive industry
  • Good ductility and energy absorbing properties combined with good strength and castability
Alloy: AM20
  • For special safety components
  • Offers high ductility and impact strengths
 Alloy AL [%] Mn [%] Zn [%]
 AZ91

 8,5-9,5

 0,17-0,40

 0,45-0,9

 AM60

 5,6-64

 0,26-0,50

 0,2

 AM50

 4,5-5,3

 0,28-0,50

 0,2

 AM20

 1,7-2,5

 min. 0,20

 0,2

 Composisions of Mg die casting alloys.

Alloy


UTS
[Mpa]

YS
[Mpa]

Compressive
Strength [Mpa]		Fracture
Elongation [%]		Young's
Modules [Gpa]		Impact
Strength [J]
 AZ91

240 

160 

160 

 3 

45

  6 

 AM60

225 

130 

130 

 8 

 45 

17 

 AM50

210 

125 

125 

10 

 45 

18 

 AM20

190 

 90 

 90 

12 

 45 

18 

Mechanical properties of Mg die casting alloys.

THIXOMOLDING ®

Thixomolding ® is an high speed, semi-solid magnesium injection molding process. The process transforms room-temperature magnesium chips, heated to a semi-solid slurry inside a barrel and screw, into precision-molded components. Secondary de-binding or sintering is not necessary and this technique combines the best of plastic injection molding and diecasting.

The typical tolerances and are as following:

  • Lineair tolerances ± 0.025mm /25.4mm
  • Flatness tolerances ± 0.076mm to 76.2mm up additional 0.025mm /25.4mm

Compared to plastic parts the advantages are:

  • Higher stiffness with thinner walls; 0.5mm nominal
  • 100% recycable
  • EMI/RF Shielding  > 85 dBat 0.5mm Mg0
  • No sink marks
  • Higher ductility
  • Complete heat management (heat sink)