The Semi-Solid Process

What Is A Thixotropic or Semi-Solid Metal?

• A Metal With Very High Apparent Viscosity At Rest:
  Metal can be manipulated as a solid.
• A Metal With Moderate Apparent Viscosity Under Shear:
  Laminar non-turbulent flow during mold filling.

SEMI-SOLID METAL PARTS VS. FORGINGS AND
CASTINGS

Forging Highest Cost High Mechanical Properties Long Process Lines Further Machining Required     Casting Lower Cost Lower Mechanical Properties Complex Shapes		Semi-Solid Metalforming Best Cost to Performance Ratio Formability of Liquid Metal Mechanical Properties of Forgings Near Net Shape
		Thixotropic Metal Controlled Forming Process

 

Advantages of SSM Process

In Terms of Process
Lower Injection Temperature
Extended Die Life
Cleaner and Safer Environment
Higher Speed Part Forming

In Terms of Product
Less Air Entrapment
Less Solidification Shrinkage
Fine Grain Structure
Heat Treatable Products
Forming of Intricate Parts
Less Machining (NNS)

Process Flow 

Dendritic Structure       Step 1 Molten Metal with Alloying Elements	Step 2 DC/Billets Cast with Dendritic Structure		Step 3 Cut into Slugs
	SSM Cast Structure Step 5 Semi-Solid Forming by Injection into the Die.		Step 4 Slug Heating to About 50/50 Liquid/Solid. Dentritic Structure Changes to Spheroidal Structure - Termed Semi-Solid Thermal Transformation (SSTT).

 

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