Oscillating Arc Welding Nozzle for Aluminum Hot Crack Suppression
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Solution Overview
Problem
Aluminum alloy welding hot cracks occur due to weak fluidity of liquid metal, coarse microstructure, and segregation of impurity elements, leading to crack formation and propagation during the welding process.
Innovation Solution
An electric arc oscillation mechanism is employed to refine the microstructure of the weld joint, reduce impurity element segregation, and enhance the fluidity of liquid metal, using a welding device with a gas-electric slip ring, hollow shaft drive unit, and curved contact tip to stir the weld pool and promote the flowback of liquid metal to dendrite gaps, thereby reducing crack generation and increasing crack resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If dendritic crystal develops and liquid metal has weak fluidity, then the microstructure forms, but liquid metal is retained between dendritic crystals forming a liquid film with poor plasticity that is prone to cracking
Solution Approach 1:
The patent employs electric arc oscillation (mechanical vibration) to stir the liquid metal in the weld pool, improving its fluidity. This vibration prevents liquid metal from being retained between dendritic crystals, destroying the continuity of liquid films and reducing crack formation while maintaining the desired microstructure.
Solution Approach 2:
The patent changes the fluidity parameter of liquid metal through electric arc oscillation. By modifying the physical state and flow characteristics of the liquid metal, the process ensures better distribution and prevents the formation of weak liquid films between dendritic crystals, thereby improving crack resistance.
2Reliability
If electric arc oscillation is applied to improve liquid metal fluidity and refine microstructure, then crack resistance increases, but the device complexity increases due to additional components
Solution Approach 1:
The welding wire serves multiple functions: it provides filler material for the weld and simultaneously acts as the electrode that generates the electric arc for oscillation. This multi-functionality reduces device complexity by eliminating the need for separate oscillation generation components while still achieving the desired liquid metal stirring and microstructure refinement.
Solution Approach 2:
The welding process itself generates the electric arc oscillation through the interaction of the welding wire and workpiece. The system uses its own operating parameters (arc current, wire feeding speed) to create the oscillation effect, rather than requiring external vibration sources, thereby simplifying the overall device structure.
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
The electric arc oscillation effectively refines the weld joint microstructure, reduces crack generation, and increases the resistance to crack propagation, thereby suppressing the occurrence of welding hot cracks in aluminum alloy welds.
Implementation Method 1
By an electric arc oscillation, the flow of liquid metal is facilitated
Implementation Method 2
By an electric arc oscillation, the liquid weld pool of aluminum alloy welding is stirred to improve the fluidity of liquid metal
Implementation Method 3
refine the microstructure of the weld joint, make the low-melting point eutectic be in dispersive distribution
Implementation Method 4
During a welding cooling process, the weld joint and its heat affected zone metal located at a tail end of the weld pool are in a solid-liquid coexistence stage
Implementation Method 5
A welding device for suppressing welding hot cracks includes... a curved contact tip... By an electric arc oscillation
Implementation Method 6
By an electric arc oscillation, the flow of liquid metal is facilitated
Data Source
AI summary
A welding apparatus comprising a first fixing plate and a second fixing plate arranged at an interval; a gas-electric slip ring is connected to the side of the first fixing plate facing the second fixing plate; a hollow shaft drive unit is connected to the side of the second fixing plate facing the first fixing plate; a conductive link is connected to the hollow shaft drive unit and passes through the second fixing plate; a curved conductive nozzle is connected to the conductive link on the outer side of the second fixing plate; and a plurality of support rods are uniformly distributed around the rotational axial direction of the hollow shaft drive unit, and are respectively connected to the first fixing plate and the second fixing plate; the hollow shaft drive unit drives the conductive link to rotate, and the conductive link drives the curved conductive nozzle to oscillate.