The liquid silicon infiltration process – also known as the LSI process (liquid silicon infiltration) – is divided into three main steps: shaping, pyrolysis and silicon infiltration. For small-batch orders, an additional preparation step of prepreg manufacturing is conducted before the shaping process, ensuring a start in production with a homogenous and storable semi-finish product.
We only use certified, high-performance carbon fibers as basis for our fiber reinforced ceramic materials. We work with both novolak and high-temperature thermoplastics as our polymer components.
Shaping takes place at a temperature of up to 400 °C using a pressing process. We can produce plate sizes from 100 x 100 to 1000 x 1000 mm² with a maximum thickness of 20 mm.
The pyrolysis takes place at temperatures ≥ 1000 °C under a nitrogen atmosphere. Complex components are then machined near net shape from the C/C (carbon fiber reinforced carbon). As a result of the pyrolysis, an open, interconnecting pore network is created, which is required for the silicon infiltration in the last process step.
The silicon infiltration takes place under vacuum at temperatures above the melting point of silicon (> 1420 °C). In contact with silicon, silicon carbide is formed from carbon. At the end of the process chain, the C/SiC consists of residual silicon, carbon fibers embedded in a carbon matrix and silicon carbide. Due to the high degree of hardness and the complex structure, finishing is time-consuming and requires our special know-how.
