Constricted Arc Build-Up Welding to Prevent Nozzle Clogging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing build-up welding methods face issues with nozzle clogging due to material accumulation, leading to reduced precision, increased maintenance costs, and potential device failure, as well as decreased surface quality and production shutdowns.
Innovation Solution
A method involving a device with a nozzle and working gas area that forms a constricted arc between the electrode and workpiece, allowing precise feeding of powdery or wire-shaped material into the arc, preventing material accumulation and enhancing precision and durability by dynamically adjusting arc power and gas flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If material is fed axially into the arc through the electrode, then manufacturing precision is improved, but the nozzle becomes clogged due to material accumulation
Solution Approach 1:
The harmful function of material accumulation on the nozzle is eliminated by extracting the material feed path from the nozzle region. Material is now fed axially through the electrode interior to the arc, separating the material delivery path from the nozzle, thus preventing nozzle clogging while maintaining precision.
Solution Approach 2:
The electrode serves as an intermediary structure that combines both the electrical function (conducting current to form the arc) and the material delivery function (housing the material feed channel). This mediator role allows precise material delivery to the arc without involving the nozzle in material handling, thus preventing clogging.
2Ease of operation
If the arc is allowed to migrate, then ease of operation is improved, but manufacturing precision deteriorates
Solution Approach 1:
The electrical parameters (current, voltage) and gas flow parameters are optimized to stabilize the arc position. By adjusting these parameters, the arc remains stable and stationary at the intended location, preventing migration while maintaining ease of operation through controlled conditions.
3Temperature
If plasma spraying is used with a long plasma flame, then temperature is improved, but device complexity increases due to longer nozzle requirements
Solution Approach 1:
The function of heating material is extracted from the nozzle and transferred to the arc region. The nozzle is shortened to only the extent necessary for electrical insulation, while the material heating and melting occurs in the arc where the extended plasma flame provides high temperature without requiring a long nozzle.
Solution Approach 2:
The arc acts as an intermediary heating zone between the shortened nozzle and the workpiece. The extended plasma flame in the arc provides the necessary high temperature for material processing without requiring the nozzle to be long, thus reducing device complexity while maintaining high temperature capability.
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 ensures precise application of material, prevents nozzle clogging, and increases the durability of the welding device, maintaining high precision and reducing maintenance costs while allowing for controlled atmosphere and gas composition optimization.
Implementation Method 1
an arc is ignited between the workpiece and a current-carrying electrode and is maintained by the current flowing through the electrode, arc and workpiece
Implementation Method 2
the localized liquefaction of metals
Implementation Method 3
flooding the working gas area with a working gas to constrict the arc in the direction of the workpiece
Implementation Method 4
The powder exits the plasma flame in a molten state and at a high speed and impinges on a surface to be treated
Implementation Method 5
the liquid droplets solidify instantly
Data Source
AI summary
A method of build-up welding a powdery or wire-shaped material onto a workpiece, which is preferably a flat substrate, by means of a device which comprises a substantially rod-shaped electrode, the electrode having at least one material feed channel extending in its interior, the device comprising a nozzle surrounding the electrode, the method comprising the following steps:forming the arc as a transferred arc between the electrode and the workpiece or as a free-standing arc between the electrode and the nozzle,flooding the working gas area with a working gas to constrict the arc in the direction of the workpiece,feeding the powdery or wire-shaped material into the constricted arc andmoving the device across the workpiece as the powdery or wire-shaped material is being fed into the constricted arc.