In-Situ defect detection and monitoring for laser powder bed fusion using a multi-sensor build platform

In additive manufacturing (AM), the laser powder bed fusion (LPBF) process allows to manufacture complex components. Due to the high energy input and the resulting residual stresses, the structural integrity of the built component is at risk. However, these areas lie within the powder bed and are difficult to monitor. In this paper a new method was developed to monitor the process by measuring the heat flow inside of the build plate to detect possible process interruptions. This is achieved by a multi-sensor build platform which measures the temperature below the build plate. Furthermore, the method offers insights about the discrete temperature history based on the heat balance.