Additively manufactured metal tooling for cure optimisation in composite manufacturing

The selection of tooling for composite manufacturing is a critical step in ensuring the quality of the resultant composite parts. The energy consumed during part manufacturing is not only used to evolve the composite properties but a substantial proportion of it is used to heat the tooling as well. Additive manufacturing (AM) offers a viable solution to reducing the tooling mass by generating complex tool architectures that can withstand the manufacturing process while offering reduced mass and additional functionalities such as cooling channels and sensor integration. A series of 16 lattice steel tools were additively manufactured and used to cure flat composite specimens. The thermal profile of the composite curing was monitored to characterise the thermal responsiveness of the tools. The curing of composites on equivalent monolithic tools of constant thickness ranging from 1- 10 mm was numerically simulated using a cure-coupled heat transfer model. The results indicate that AM tools with lattice architectures can achieve heating rates higher than 83% of the set rate while keeping the exothermic overshoot temperature below 30% of the setpoint, which its monolithic counterparts couldn’t achieve. Hence lattice structures enabled by AM can push the design space into regions previously unavailable to tooling design.