Hot Filler Wire Laser Welding to Prevent Start-Up Arcing
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Solution Overview
Problem
Conventional filler wire welding methods, such as gas-tungsten arc welding, face challenges with wire slippage and arcing issues at the start of the process, leading to burnthrough and spatter, especially when the initial current is high, causing the wire tip to burn away and form an arc.
Innovation Solution
A system combining a laser subsystem for high-intensity energy and a hot filler wire feeder with a pulsed direct current power supply, where the filler wire is resistance-heated and synchronized with the laser beam to maintain contact and prevent arcing by controlling the heating current based on contact with the workpiece, using sensing and current control to adjust the power supply accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high initial current is applied to the filler wire, then welding speed increases, but the wire tip burns away and causes arcing
Solution Approach 1:
The power supply dynamically adjusts the heating current based on real-time wire contact status. When the wire makes contact with the workpiece, the system detects the change in electrical resistance or voltage and automatically reduces or interrupts the heating current to prevent tip burnout, while allowing high current during non-contact phases for rapid welding
Solution Approach 2:
The system incorporates a feedback mechanism that continuously monitors the electrical parameters (voltage, current, or resistance) between the wire and workpiece. This feedback loop enables the power supply to detect wire contact and adjust the heating current accordingly, preventing arcing while maintaining high welding speeds
2Productivity
If filler wire is used with traditional arc welding, then deposition rate increases, but wire slippage and arcing occur
Solution Approach 1:
The system replaces the traditional arc-based heating mechanism with a controlled resistance heating system. Instead of relying on arc discharge to melt the wire, the system uses precisely controlled electrical current through the wire's resistance, eliminating uncontrolled arcing and spatter while maintaining high deposition rates
Solution Approach 2:
The system changes the heating parameter from uncontrolled arc temperature to controlled resistance heating current. By regulating the current magnitude and duration based on wire contact detection, the system achieves consistent wire melting without the harmful effects of arc discharge, reducing spatter and improving weld quality
3Productivity
If wire feed speed is increased, then welding efficiency improves, but wire contact control becomes difficult
Solution Approach 1:
The system uses the wire feed mechanism itself to perform the sensing function. The electrical parameters of the wire feed circuit are monitored to detect when the wire makes contact with the workpiece, eliminating the need for separate sensing devices and enabling automatic control even at high feed speeds
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
This approach reduces the risk of arcing and spatter, allowing for higher welding speeds with reduced heat input, minimal distortion, and the ability to weld coated materials without shielding gas, achieving low porosity and spatter rates while maintaining weld quality.
Implementation Method 1
applying a high intensity energy source, such as a laser beam 110, to heat the workpiece 115
Implementation Method 2
The wire is fed through a contact tube toward a workpiece and extends beyond the tube. The extension is resistance-heated such that the extension approaches or reaches the melting point
Data Source
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AI summary
A method and system to weld or join workpieces (115) employing a high intensity energy source (100) to create a weld puddle (901, 1022) and at least one resistive filler wire (140) which is heated to at or near its melting temperature and deposited into the weld puddle (901, 1022).