Developing a new metal forging concept
The feasibility of using surface heating elements in metal forging applications has been assessed. A prototype tool was developed that could raise the temperature of aluminium test panels to their hot forging point of 450°C.
The Centre for Intelligent Dynamic Communications (CIDCOM) has built upon previous research enabled by the Impact Acceleration Account (IAA) to transfer knowledge and experience from composite material manufacturing to metal forging. A prototype tool that could accurately control thermal transfer from a surface tool for creating composite components had potential to be applied to other sectors. The metal forging industry faces similar challenges to aerospace: high capital expenditure and operating costs of manufacturing equipment. The challenge was to determine if the prototype tool could be adapted for the very different environment of metal forging.
The biggest challenge was to achieve a much higher temperature required to forge metals. Aluminium which is commonly used in aircraft and automotive vehicles needs to reach 450°C to allow hot forging. Mica insulated heater pads were found to be able to reach this temperature with appropriate insulation. A zonal configuration of the heater was created between layers of steel to provide rigidity for the heated surface. A microcontroller was used to relay commands and data between the heater pads and a computer so that the temperature profile could be tracked and adjusted over the manufacturing period.
The tool was able to reach the desired temperature of 450°C. High thermal conductivity of steel allowed rapid conduction of thermal energy from one zone into adjacent ones which increased energy consumption dramatically. The controller had to be adjusted to account for the high temperature variations within a given time period due to the high thermal losses and unusual thermal transfer dynamics between each zone.
The positive results of the tool indicate that with further investment and research, a higher technology readiness level may be possible. To reduce thermal conductivity between heater zones, it is believed that using discrete metallic regions separated by low thermal conductive material like carbon fibre may have potential.