Deep Laser Welding Beam Shaping to Prevent Weld Humping
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Solution Overview
Problem
Conventional laser-based deep welding methods experience a humping effect at critical feed rates, leading to irregular weld seam topography and material deficiencies, which weaken the weld joint and increase the likelihood of leakage between joined parts.
Innovation Solution
The method involves using a laser beam with a deep welding laser beam component and an additional melting laser beam component to increase the width of melt pool channels, reducing the flow velocity of metal melt and allowing for higher feed rates without the humping effect by targeted beam shaping, such as concentric or offset beam configurations, to enhance the flow cross-section and control thermal fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the feed rate is increased to achieve higher productivity, then the welding speed improves, but the humping effect occurs leading to weld seam irregularities and material deficiencies
Solution Approach 1:
The laser beam is segmented into multiple independent beam components (at least three beams) that can be individually controlled. This segmentation allows different regions of the workpiece to receive tailored heating, with specific beams targeting melt pool channels to control capillary flow and prevent humping while maintaining high overall welding speed
Solution Approach 2:
Different laser beam components are directed to different locations with specific functions: some beams create and maintain the vapor capillary, while other beams specifically heat and widen the melt pool channels on both sides of the capillary. This local quality differentiation enables precise control of metal melt flow velocity in critical regions without compromising overall welding productivity
2Device complexity
If conventional laser beam welding is used to maintain simple process setup, then the device complexity remains low, but the feed rate is limited due to the humping effect
Solution Approach 1:
The laser beam device is designed with multi-functionality, where the laser system performs multiple tasks simultaneously: creating the vapor capillary, forming melt pool channels, controlling metal flow, and producing the weld seam. This universal approach allows high feed rates without requiring additional specialized equipment beyond the multi-component laser system
Solution Approach 2:
The laser beam components are dynamically controllable in terms of power, position, and timing. This dynamic control allows the system to adapt to different welding conditions and material properties, enabling high-speed welding while maintaining precise control over the complex multi-beam interaction with the workpiece
3Use of energy by moving object
If the melt pool channel width is small to maintain focused energy, then the energy concentration is high, but the metal melt flow velocity becomes too high causing humping effect
Solution Approach 1:
The energy delivery is segmented into multiple beam components, with specific beams dedicated to widening melt pool channels. This segmentation allows the main capillary-forming beam to maintain high energy concentration while auxiliary beams add targeted energy to expand channel width and reduce metal flow velocity
Solution Approach 2:
The invention changes the physical parameters of the laser beam system by introducing multiple beams with different power levels, positions, and focal characteristics. These parameter changes enable simultaneous achievement of high energy concentration for capillary formation and sufficient melt pool channel width for controlled metal flow
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 enables a significant increase in feed rate without generating a humping effect, resulting in a closed weld seam with reduced thermal distortion and improved joint integrity, applicable to various material thicknesses from thin electrochemical components to thicker car body construction materials.
Implementation Method 1
The laser beam generates a vapor capillary in the material of the parts to be joined, which is surrounded by a melt pool
Implementation Method 2
This occurs with the formation of a capillary flow, in which a metal melt located at the capillary front flows through melt pool channels formed on both sides of the vapor capillary
Implementation Method 3
The melting laser beam component increases the width, i.e. the flow cross-section, of the melting channels. This reduces the flow velocity of the metal melt flowing through the melt pool channels
Data Source
AI summary
A method for laser-based deep welding of at least two parts to be joined, in which a laser beam device generates a laser beam with a deep welding laser beam component, which is moved at a feed rate along a joint. The deep welding laser beam component generates a vapor capillary in the material of the parts to be joined, which capillary is surrounded by a melt pool and which moves with the laser beam in the welding direction through the material of the parts to be joined, forming a capillary flow, in which a metal melt located at the capillary front flows via melt pool channels formed on both sides of the vapor capillary in the direction of the capillary rear side and solidifies there.