Press release 19-Mar-2018: Elkem ASA has acquired the UK company TM Technology Ltd and its production of the foundry alloy, Tenbloc®. 


Over a period of 30 years TM Technology has developed and produced Tenbloc at its dedicated manufacturing plant in the United Kingdom. Tenbloc is a unique in the mould inoculant block which provides consistent, reliable and cost effective inoculation for ductile and grey irons. This assists foundries to produce castings with improved metallurgical structures and mechanical properties.


Tenbloc is manufactured using powder metallurgical techniques which helps to ensure the blocks have a low thermal conductivity. This means Tenbloc starts to dissolve immediately and continuously throughout the pour time ensuring all the metal, particularly the first metal poured, is effectively inoculated. Blocks are available in a weight range from 5 to 1000g with precise weight control and dimensional tolerance. This is critical in maintaining accurate and reliable addition rates at the latest stage of the inoculation process.


The use of Tenbloc in the mould is the latest possible stage at which inoculant can be added. This means the amount of inoculant to be used can be reduced to a minimum as there is no inoculant fade and as such it is a cost effective and efficient use of inoculant. Typical addition rates are 0.1% but these can be adjusted to suit specific customer requirements.


Careful selection of the raw materials ensures Tenbloc has uniform and consistent chemistry, providing homogeneous nucleation of the iron and is available in a wide range of analytical grades which can be tailored to suit specific foundry requirements for both ductile and grey iron.

Close control of all stages of production gives Tenbloc a number of advantages:

It is free from impurities, eliminating the introduction of undesirable elements in the iron.

There are no slag inclusions, gas holes or porosity.

The unique metallurgical bond formed during production is important for immediate and controlled dissolution.


Case studies

  • Replacing a 0.65% addition of a Zr containing ladle inoculant with a 0.11% addition of an MZ grade Tenbloc has improved metallurgical structure and significantly reduced the amount of inoculation addition at a South American foundry. This has reduced the cost of inoculation by over 25%.


  • A foundry producing 40.3 ductile iron could not consistently achieve reliable Charpy impact properties using ladle inoculation and a cast block in the mould. Changing the cast block for a 40g standard grade Tenbloc has increased the impact properties by 15% allowing the foundry to reliably produce this grade in the as cast condition.


  • A foundry producing thin section ductile iron castings which are poured at 50kgs in 3-4 second's (15kgs/second) had problems with carbide in the thin section when using a cast in the mould block. When they changed to a 50g MZ grade Tenbloc the problem was overcome due to improved dissolution characteristics.


  • The metallurgical structure of a grey iron casting has improved when using MZ grade Tenbloc instead of cast blocks in the mould. The micrographs opposite show the improvement with Tenbloc compared to a cast block.