Sigma Labs announces publication of multi-sensor quality inference and control patent for AM processes
Sigma Labs, Inc., Santa Fe, New Mexico, USA, has announced the June 30, 2016 publication of its US Patent Application No. US 2016/0185048; Multi-Sensor Quality Inference and Control For Additive Manufacturing Processes. This patent application is related to the real-time quality analysis of Additive Manufacturing processes and the characterisation of material properties using acoustic signals emitted during AM, which can be used in addition to optical signals to simplify the qualification of printed parts.
It also encompasses a multi-sensor quality inference system for Additive Manufacturing that is capable of discerning and addressing three quality issues: process anomalies, or extreme unpredictable process events uncorrelated to process inputs; process variations, or differences between desired process parameters and actual operating conditions; and material structure and properties, or the quality of the resultant material created by the AM process. It further embodies the use of the gathered sensor data to evaluate and control Additive Manufacturing operations in real time.
Mark Cola, Sigma Labs CEO, stated, “We are at the forefront of a new era in Additive Manufacturing and are very pleased to announce the publication of this patent which evidences our leadership in real time process control capabilities. Crucial to our continued growth and emerging market leadership is securing our intellectual property portfolio. The publication of this patent application further serves these goals.”
Sigma Labs’ application, which has a priority date of November 18, 2014, describes how optical sensors can be used to measure oscillations (e.g., greater than 1,000 Hz) in the melt pool and how these readings could be augmented by artificially illuminating the melt pool with a laser to help collect specular reflections that include oscillation frequency information. This application also describes how an acoustic sensor can be used to acoustically monitor a build process by listening for micro-cracking occurring as a workpiece is being built and may be used to eliminate post-build quality control processes such as CT scanning, which adds an extra process to production and can be quite time intensive.
According to Sigma, recent trends suggest that the use of acoustic characterisation during AM operations may become a widespread technique in the AM industry.
