BUP49 - AddTemper

The project is focused on the processing of high-carbon steels in additive manufacturing. These steels are valued for their high strength and hardness and are used in applications such as tools, machine parts, and automotive components. However, they are difficult to process because of their propensity to crack. Current techniques such as high-temperature heating of the build platform reduce cracking, but are energy-intensive and inflexible. Consequently, new concepts are therefore needed to process these materials economically.

Aim

The "Add-Temper" project is pursuing an innovative approach through the development of a temperature-controlled in-situ laser heat treatment (TIHT) technique, which is conducted directly during the PBF-LB/M built-up process (Powder Bed Fusion using Laser Beam). In the PBF-LB/M process, metal powder is melted layer by layer using a laser beam to create complex components. Also, the laser beam is employed as a flexible heat source, enabling the targeted and controlled heating of individual layers within a component. This precise heat treatment reduces residual stresses during the manufacturing process and prevent the formation of cracks. Furthermore, TIHT allows for the selective modification of component properties by creating distinct temperature zones within a component. This offers a novel avenue for the design and utilisation of additively manufactured components.

Approach

• In-house developed modular PBF-LB/M research platform with open control for maximum control over the process
• Temperature-controlled in-situ laser heat treatment (TIHT) with high-speed quotient pyrometer to record the component temperature
• Thermographic camera for recording the temperature history
• Scanning electron microscope images and hardness measurements to analyze the material properties and microstructure formation 

Benefit

Overall, the results of the AddTemper project supports industry in processing new groups of materials that are prone to cracking, such as high-carbon steels. This significantly expands the range of applications for additive manufacturing.