A new method for determining and improving the accuracy of a powder bed additive manufacturing machine

摘要

Since the additive manufacturing machines are not in mass production, there are usually differences between machines from the same brand and model. In previous production tests done in powder bed fusion (PBF) machines, large deviations have been discovered. Therefore, a method for measuring the accuracy of the additive machine is necessary. A new method has been developed, with characteristics similar to those of a coordinate measuring machine (CMM). The CMM method has been inverted, and through a nonlinear optimization process, reconfigures certain key points to make an analysis of the machine accuracy. Using this method, one can detect abnormalities or deviations in the laser positioning, or find that the machine make parts that have certain offsets which deviate from that of the computer model. The developed test will help include the additive machining center into an automated hybrid cell, where traditional CNC-machines interact and all machines work under a common cell control system. The new method has been simulated and applied in the workshop, where it has been found that the product deviations has been reduced to almost a fifth of the original value.