Logo Unitherm

Geopolymer Foundry

Technology of production of molds and cores in our new foundry is based on self-hardening mixture with a geopolymer-based binder system. Mixtures based on these binders are used in grey cast iron and steel foundries and in construction industry. Due to lower melting and casting (in comparison to grey cast iron and steel foundries) temperatures the process must have been significantly altered in order to ensure such type of sand mixture could be used with aluminium.

This technology is an ecological alternative for widely used toxic, highly flammable and carcinogenic furan compounds, which we as a foundry allocated in a protected area, cannot use.

The technology allows us to produce shapes that are more complex and also allows positioning chills on places and areas where it is very difficult or unrealistic in comparison to the foundry using bentonite mixture. We can also produce larger parts with minimum surface defects such as sand bucles or metal penetration thanks to the fact that no additional water is mixed into the sand mixture.

The complete line is made up of continuous mixers, compaction table, rotary cranes with endless slewing, gantry crane, melting furnaces, vibratory grid and sand reclamation system.

Depending on dimensions, there is possibility to produce parts weighing up to 150 kg. Moulding frames have max. size 1200 x 1200 mm.

The whole production line is made up of six basic units:

  1. Core manufacturing,
  2. mould manufacturing,
  3. alloy melting and preparation,
  4. mould jointing and casting,
  5. core- and mould breaking,
  6. sand reclamation.

Finishing operations

  1. Trimming and grinding of gatings and risers.
  2. Blasting with chrome steel stainless granulate and corundum mixture.
  3. Pressurizing of castings up to max. pressure of 6 bar.
  4. Heat treatment T4, T6.
  5. Assemblies according to customer specifications.
  6. In cooperation, we offer the following surface treatment based on customer specifications - protection against corrosion, powdered surface finish, anodizing etc.

Features


Suitable for smaller series

Large number of cores

Complex cast shape

Large parts


Machining Shop

Do you need machined casting? We have everything we need for turning, milling and drilling of all assortment of products. Have a look!

More about machining shop

Material

Our sand casting aluminium foundry offers the following aluminium alloys:

Alloy

Solution

Rm - tensile strength
(MPa)

Rp0.2 0.2% proof strength
(MPa)

A - Min. elongation at fracture
(%)

Brinell hardness
(HBW)

AlSi7Mg0,3






EN AC-42100

A356.0

ST6

230

190

2

75

3.2371

AC4CH








AlSi10Mg(a)






EN AC-43000

A03590

SF

150

80

2

50

3.2381

AC4A

ST6

220

180

1

75








AlSi8Cu3






EN AC-46200

380.0

SF

150

90

1

60


AC4B








AlMg3(b)






EN AC-51100


SF

140

70

3

50

3.3541









AlZn10Si8Mg






EN AC-71100


SF

210

190

1

90










T6

Solution heat treated and then artificially aged



F

Fabricated (as cast)



We can also offer processing of other aluminium alloys.

Melting is carried out in gas crucible furnaces. The treatment of molten aluminium is routinely done by means of FDU degassing units. The quality of the molten material is evaluated by means of spectrum analysis and by devices measuring the level of molten material gasification.

Feel free to contact our sales department with any questions concerning casting technologies

Adam Rokos
e-mail: arokos@unitherm.cz
mobile: (+420) 777 792 211
phone: (+420) 488 388 112

Lenka Bienová
e-mail: bienova@unitherm.cz
mobile: (+420) 777 792 203
phone: (+420) 488 388 113