Optical Thermal Energy Sensing for Additive Manufacturing Quality Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current additive manufacturing processes lack effective non-destructive methods for verifying the mechanical, geometrical, and metallurgical properties of production parts, as conventional quality assurance testing often requires destructive testing, which is not applicable to production parts.
Innovation Solution
The implementation of optical sensing techniques to track in-process physical phenomena and determine thermal energy density (TED) during additive manufacturing, using sensors that monitor energy radiated from the build plane, allowing for real-time adjustment of process parameters to prevent defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional quality assurance testing is used to verify part properties, then accurate quality verification is achieved, but the part is destroyed
Solution Approach 1:
The patent replaces mechanical/physical destructive testing methods with optical sensing techniques that detect thermal radiation emitted during the additive manufacturing process. Optical sensors measure thermal energy density and radiated power to infer melt pool characteristics and process quality without contacting or damaging the part, thereby substituting mechanical testing with optical measurement systems.
Solution Approach 2:
The patent uses thermal radiation as an intermediary carrier to convey information about the melt pool state and process quality. Instead of directly measuring physical properties that would require part destruction, the system detects thermal radiation emitted by the molten material, which serves as a non-invasive mediator that carries diagnostic information about the manufacturing process and resulting part quality.
2Reliability
If optical sensing techniques are implemented to track in-process physical phenomena, then non-destructive quality monitoring is achieved, but device complexity increases
Solution Approach 1:
The patent integrates optical sensing capabilities into the existing additive manufacturing system architecture, where the same optical infrastructure serves multiple functions: monitoring thermal radiation for quality control, characterizing melt pool dynamics, and potentially guiding process adjustments. This multi-functional approach reduces the need for separate dedicated testing equipment and minimizes overall system complexity.
Solution Approach 2:
The patent implements a feedback loop where optical sensors continuously monitor thermal radiation during manufacturing, and the measured thermal energy density is used to adjust process parameters in real-time. This closed-loop control system automates quality assurance, reducing the need for complex post-processing inspection equipment and simplifying the overall verification workflow.
3Manufacturing precision
If thermal energy density measurements are performed during additive manufacturing, then process control accuracy is improved, but energy measurement requirements increase
Solution Approach 1:
The patent leverages the thermal radiation that is naturally emitted by the molten material during additive manufacturing as the measurement source. The process itself generates the thermal energy signals needed for monitoring, eliminating the need for external heating sources or additional energy input for measurement purposes. The system essentially uses the process's own thermal output for self-diagnosis and control.
Solution Approach 2:
The patent replaces direct physical measurement methods that would require additional energy input (such as contact thermocouples requiring heating or cooling) with optical detection of thermal radiation. This substitution uses passive optical sensing to detect the thermal energy already present in the melt pool, significantly reducing the additional energy requirements for measurement compared to active thermal measurement techniques.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables non-destructive quality inference and process control, reducing discontinuities in the melt pool and improving the accuracy of additive manufacturing by identifying potential defects and optimizing energy distribution, thereby enhancing the quality and consistency of produced parts.
Implementation Method 1
measuring an amount of energy radiated from the build plane during each of the plurality of scans using an optical sensor monitoring the build plane
Data Source
AI summary
This disclosure describes various methods and apparatus for characterizing an additive manufacturing process. A method for characterizing the additive manufacturing process can include generating scans of an energy source across a build plane; measuring an amount of energy radiated from the build plane during each of the scans using an optical sensor; determining an area of the build plane traversed during the scans; determining a thermal energy density for the area of the build plane traversed by the scans based upon the amount of energy radiated and the area of the build plane traversed by the scans; mapping the thermal energy density to one or more location of the build plane; determining that the thermal energy density is characterized by a density outside a range of density values; and thereafter, adjusting subsequent scans of the energy source across or proximate the one or more locations of the build plane.