Sitomb® – Silicon tombac die casting
Sitomb® is the new construction alloy for highly-stressed and accurate components. Its characteristics are similar to stainless steel. But there is one crucial advantage: Sitomb can be processed in commercial high pressure die casting, which is not possible with stainless steel. Castings made of stainless steel need to be processed using the more complicated investment casting procedure.
Maximum corrosion resistance
Sitomb castings are very resistant to corrosion because of their high copper content of 80%.*
High strength and elongation at break
Strength properties up to 700 MPa are possible. In any case a minimum of 500 MPa is guaranteed. Despite this excellent strength characteristic, high elongation values of >10% are reached before the part breaks.
Using the high pressure die casting method for our production allows us to produce more parts per time unit compared to other methods. Hence, we reach low unit costs.
When is Sitomb used?
Mainly in these situations:
Parts resulting from steel investment casting are too inaccurate or expensive
Parts resulting from Metal Injection Moulding (MIM) are too inaccurate, expensive or brittle
Parts resulting from zinc alloy die casting reach too low levels on strength and break in the long-term
The corrosion resistance of your part is insufficient
Other reasons for the use
The brass that is used is too soft
Slip properties have to be improved
Antibacterial characteristics are required
Silicon tombac – Sitomb®
Sitomb® is the result from decades of alloy development and process improvement at BREUCKMANN. With specific limitations in the tolerance range for alloy elements of silicon tombac complying with DIN EN 1982 (2.0492.05, C87800, CC761S) and targeted micro alloying, we were able to achieve the metallurgical optimum for our characteristics.
To produce Sitomb, brass and silicon are mixed and afterwards quickly cooled down. At high temperatures around 1000°C silicon is able to move freely within the metal lattice. As soon as the metal cools down to room temperature, the silicon atoms get stuck in specific positions within the interstitial metal lattice. Subsequently, they tense up the structure which results in higher hardness and strength of the component.
– A similar behavior can be observed when carbon is added to steel. –
The fast solidification leads to a fine grain structure having good mechanical characteristics. Additionally, using silicon for alloys results in an unusual behavior during the local extension when cooling down (avoidance/reduction of casting porosities).
How can I order my customized part made of Sitomb®?
To get a first impression of our material, you can order a customized prototype online. We named this process “rapid Sitomb”. It enables you to order first samples without the initial investment of a die casting tool.
You are able to order directly online. Click here, upload your 3D-data online and instantly receive the unit piece.
2.) Series production:
To completely benefit from Sitomb, it is necessary to make a one-time investment in a die casting tool. In relation to the quantity you need, one can choose between a small series die casting tool and a series die casting tool.
Feel free to contact us using the form below.
Series production with Sitomb®
Get in touch with us through this form.
In three steps to your die casting tool for series production of your part made of Sitomb.
Ideally upload your 3D-files using an .stp file.
Until now we only knew investment casting and MIM as production processes for high strength and highly accurate parts. Die casting with Sitomb is a real alternative for us. Customer from the Locking Technology Industry
In our case the investment in a die casting tool paid off after 16 months. Customer from the Automotive Industry
Our MIM-Parts had to be coated to be protected against corrosion. After the switch to Sitomb corrosion and coating are no issue for us anymore. Customer from Medical Engineering
There is a high potential for cost reduction compared to parts resulting from investment casting. Customer from the Lock and Fitting Industry