1. thixotropic semi-solid metal discovery of the phenomenon (1971 D.Spencer)

Pb-Sn alloy in a series of solid and liquid coexistence temperature range of viscosity measurements

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Found that by varying the stirring speed, the apparent viscosity of the liquid mixture of reversible change

Small stirring speed

→ apparent viscosity high

Stirring speed large

→ low apparent viscosity

(More than 30% of the solid phase also has the same fully liquid fluidity, this phenomenon thixotropic title)

 

 

2. Use thixotropic properties to develop new technology of metal forming (1970)

Reo-casting vision (1976 M.Flemings)

1. stirring the molten alloy is cooled to a semi-molten state → high-pressure casting (Reo-casting)

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2. The molten alloy is cooled and solidified while stirring

 

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Forming a billet having granular crystals of

 

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Reheated to a temperature of the solid-liquid coexisting

 

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It can be treated like a solid at rest

 

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In the shear stress as a liquid flow

 

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As the solid treatment (thixotropic casting)

 

 

3. Application (late 1970s-1980s _ Dow Battel Institute Inc.) on the injection molding method

The use of magnesium alloy magnesium turnings as a raw material inputs sleeve with screw

→ screw is formed by stirring the semi-molten slurry having fluidity

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Like with plastic injection molding

 

 

4. Development of magnesium alloy injection molding machine (1990 Japan Steel Works)

High-speed injection systems and high temperature, high temperature corrosion of materials born development → magnesium alloy thixotropic molding machine

 

 

5. popularity thixoforming products (the late 1990s)

MG Precision Company established → using thixoforming products in a variety of portable electronic equipment

Thixoforming manufacturers of birth