Die Casting vs Liquidmetal
Die Casting Process
Die Casting is also known as Aluminum or Magnesium Casting. These materials have a relatively low melting temperature, allowing you to hold a large vat of material in a molten state.
A single shot of material is either suctioned off from the vat or a ladle of it is poured into the shot sleeve. From there, a rod and plunger pushes the molten alloy into a steel mold.
The part comes out of the mold to net shape, good precision, and full strength. A secondary process to remove flash around the parting line is required. Other processes to improve surface finish and corrosion resistance may be desired.
Liquidmetal Process
Amorphous Metal Molding uses a special alloy designed to have an amorphous atomic structure in a solid state. Small batches of feedstock are melted in a vacuum chamber to avoid contamination from Oxygen. The melted alloy is poured into the shot sleeve where a plunger pushes the material into a steel mold.
The Liquidmetal part comes out of the mold to net shape, great precision, and with full physical properties. Secondary processes to remove the part from the runner and overflows are necessary.
Design Considerations
Parameters such as part geometry and size are dependent on the process used to make the part. The chart is a comparison of how these two manufacturing processes affect the capabilities.
Die-Casting
VS
Liquidmetal
Die-Casting
VS
Liquidmetal
Die-Casting
VS
Liquidmetal
Complex Contoured Geometries
Limits on size and wall section
Design
Flexibility
Complex Contoured Geometries
Limits on size and wall section
+/- 0.063mm
Dimensional
Tolerances
+/- .02mm (critical dim)
+/- .05mm (standard)
1 to 2 degrees internal features
0.5 to 1 degree external features
Draft
Requirements
3 degrees internal features
1 degree external features
15g to 10kg
Part Size
< 1g to 200g
0.08 to 1.1 Ra μm
Surface
Finish
0.05 to 0.35 Ra μm
0.8 mm
Min Wall
Thickness
0.3 mm
12 mm
Max Wall
Thickness
2.5 to 3 mm
Material Properties
A manufacturing process can influence the material properties of a part due to the resulting porosity or grain structure, but the main contributor to the properties is the type of material that can be used in a particular process. The melting temperature of a material and the final part geometry will dictate which manufacturing process to use.
Die-Casting
VS
Liquidmetal
Die-Casting
VS
Liquidmetal
Die-Casting
VS
Liquidmetal
150 to 283 (23-41)
Yield Strength
Mpa (ksi)
1250 (181)
.05 to .35
Standard Elasticity
% Strain
1.6
High Elasticity
63 to 100 (67-105)
Hardness
HB (Vickers)
460 (500)
No Heat-Treating Available
50 to > 500 hours salt spray
(Surface treatments common to improve)
Corrosion
Resistance
> 500 hours salt spray
1.8 to 6.6 (.066 – .24)
Density
g/cc (lb/ci)
6.8 (.25)
Process Considerations
Cost is usually a driving factor in selecting a manufacturing process. A process that gives you a lower cost part might require more up front tooling cost, and a longer engineering and development time. These trade-offs may be offset by the speed at which you can make the part if you need a high capacity process for a high volume product.
Die-Casting
VS
Liquidmetal
Die-Casting
VS
Liquidmetal
Die-Casting
VS
Liquidmetal
Medium to Ultra-high
Production
Quantities
Medium to High
Ultra-low to Low
< $0.10 to $5.00
Part Costs
Low to Average
$1.00 to $20.00
Al, Zn, Mg
Alloy
Alternatives
Amorphous alloys only
2 to 4 weeks
Production
Lead Time
4 to 6 weeks
High, $10K to $100K
Tooling
Costs
High, $30K to $100K
Process Advantages and Disadvantages
Die cast parts cannot match the strength of Liquidmetal or steel parts. When molten aluminum or magnesium cools into a solid, the material crystalizes and shrinks. This makes it difficult to control precise dimensions. Amorphous metals maintain the amorphous atomic structure of liquids when they solidify. As a result, molded amorphous metal parts match the dimensions of the mold within microns. These technologies are rarely competing for the same part because of the big differences in price and strength.
