Giga- or megacasting has been revolutionizing (aluminum) die casting for several years. While conventional structural casting primarily replaced sheet metal constructions with a single cast part, large machines now make it possible to cast several structural parts such as shock towers, longitudinal and cross members in a single very large structural part.
Subsequent heat treatment for large components
With such large components, however, subsequent heat treatment can cause considerable difficulties. For this reason, naturally hard or self-hardening alloys are the first choice for new projects. As Dr Steffen Link, Head of Chemicals at Geiger + Co. Schmierstoff-Chemie GmbH, emphasizes, changing the alloy can sometimes have a huge impact on the subsequent process steps. By dispensing with energy-intensive solution annealing, residues of operating materials are no longer removed from the castings during heat treatment in the case of naturally hard alloys. For this reason, much more attention must be paid to sufficient and reliable cleaning and pre-treatment of the structural parts when using these alloys.
New mold release agents for higher technical requirements
"As release agent manufacturers, we started tackling this challenge at a very early stage and developed new mold release agents that both meet the increased technical requirements and are as compatible as possible with downstream processes," Link stated. It has been proved that the selection of the right raw materials is crucial for the development of suitable mold release agents. For example, newly developed coating-friendly polysiloxanes can be easily washed off with suitable cleaners.
Excellent washability and easy demolding
"The newly developed release agents offer the best possible compromise between excellent washability and problem-free demolding of the castings," Link states, emphasizing at the same time that the new release agents are already being used in numerous giga- and megacasting die casting machines.
