LPBF Gas Flow Mapping With Robotic In-Chamber Velocity Sensing
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Solution Overview
Problem
Existing LPBF additive manufacturing plants face inaccuracies in gas flow velocity management, leading to defects like porosity and oxide inclusions due to theoretical CFD simulations being less precise, affecting product reliability and performance.
Innovation Solution
A mapping device and method using a robot with sensors like Pitot differential pressure, hot-wire anemometer, ultrasonic, and Doppler anemometers to accurately measure gas flow velocity within the process chamber, associating signals with coordinates for precise mapping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If CFD analysis is used to simulate gas flow velocity, then the plant design can be performed theoretically, but the measurement precision is insufficient leading to defects
Solution Approach 1:
The patent replaces complex theoretical CFD simulations with direct physical measurements using anemometers and pressure sensors. This substitution of mechanical measurement systems for computational models achieves higher precision in gas flow velocity measurement while providing tangible data for process optimization.
Solution Approach 2:
The patent introduces a recirculating pump as an intermediary device to actively control and maintain gas flow velocity within target ranges. This mechanical mediator allows precise adjustment of gas flow parameters based on sensor feedback, resolving the contradiction between measurement precision and system complexity by providing a controllable intermediate element.
2Productivity
If gas flow velocity is increased to remove by-products, then productivity improves, but harmful factors increase due to redepositing and porosity
Solution Approach 1:
The patent implements a feedback control system where anemometers and pressure sensors continuously monitor gas flow velocity, and the recirculating pump adjusts flow rates based on this feedback. This closed-loop control enables the system to maintain optimal gas flow velocity that efficiently removes by-products while preventing harmful effects like porosity and redepositing.
Solution Approach 2:
The patent dynamically changes gas flow velocity parameters during the additive manufacturing process based on real-time measurements. By adjusting the recirculating pump speed according to measured conditions, the system optimizes by-product removal efficiency while staying within safe velocity limits to prevent porosity and oxide inclusions.
3Reliability
If gas flow velocity is decreased to prevent defects, then product quality improves, but productivity decreases due to incomplete by-product removal
Solution Approach 1:
The feedback control system using anemometers and recirculating pumps enables the system to maintain the minimum gas flow velocity necessary for effective by-product removal while preventing excessive velocity that would cause defects. This real-time adjustment optimizes both productivity and product quality simultaneously.
Solution Approach 2:
The patent employs dynamic gas flow velocity adjustment during the additive manufacturing process. The recirculating pump modulates flow rates based on real-time sensor data, allowing the system to adapt gas flow conditions to match process requirements, thereby achieving both high productivity and high reliability.
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
Provides highly precise gas flow velocity mapping, reducing mapping times and improving accuracy by acquiring real-time data under actual manufacturing conditions, enhancing product quality and reliability.
Implementation Method 1
the at least one sensor is selected from among a Pitot differential pressure sensor
Implementation Method 2
the at least one sensor is selected from among a Pitot differential pressure sensor, a hot-wire anemometer
Implementation Method 3
the at least one sensor is selected from among a Pitot differential pressure sensor, a hot-wire anemometer, an ultrasonic anemometer
Implementation Method 4
the at least one sensor is selected from among a Pitot differential pressure sensor, a hot-wire anemometer, an ultrasonic anemometer, a Doppler anemometer
Data Source
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AI summary
A mapping device (7) of the gas flow in LPBF additive manufacturing plants has a robot (8) configured to be arranged inside a process chamber (2) of an LPBF additive manufacturing plant (1); a movable member (10) selectively controlled by the robot (8); a first sensor (11; 12) supported by the movable member (10) to acquire a plurality of signals correlated to the velocity of the gas flow inside the process chamber (2).