Tandem Hot-Wire Micro-Arc Heat Input Control

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Solution Overview

Problem

Existing welding systems are limited in their ability to vary heat input, which restricts the optimization of processes such as welding, joining, cladding, and brazing, as they often rely on fixed power supplies that cannot efficiently adjust heat to achieve desired outcomes.

Innovation Solution

A tandem hot-wire system that includes a high-intensity energy source and a hot-wire power supply capable of switching between different heating currents to create a micro-arc, providing increased heat input and agitation to the weld puddle, while a controller manages the duration and frequency of the micro-arcs to optimize the welding process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple welding power supplies are used to increase deposition rate, then welding speed increases, but the ability to vary heat input is limited

Engineering Contradiction:

Improvedeposition rateVSAvoidheat input variability

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the hot-wire power supply adjustable and switchable between different operating modes (first mode with lower current for baseline heating, second mode with higher current for micro-arc generation). This dynamic capability allows the system to vary heat input in real-time, resolving the contradiction between maintaining high deposition rate and achieving heat input variability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameter (current level) of the hot-wire power supply to create different operational states. By switching between first and second heating currents, the system can control whether to provide steady heating or generate micro-arcs, thereby achieving variable heat input while maintaining high productivity through the dual-mode capability.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If fixed power supplies are used, then system simplicity is maintained, but process optimization is restricted

Engineering Contradiction:

Improvepower supply configurationVSAvoidprocess optimization

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The hot-wire power supply is designed with multi-functionality, capable of operating in at least two distinct modes: first mode for baseline heating and second mode for micro-arc generation. This universal design allows a single device to perform multiple functions, providing process optimization capability without requiring multiple separate fixed power supplies, thus balancing complexity and precision.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If higher heating current is applied continuously, then deposition rate increases, but heat input becomes excessive

Engineering Contradiction:

Improvedeposition rateVSAvoidheat input

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by switching the hot-wire power supply between first and second modes in a controlled sequence. The controller initiates the first mode to heat the wire, then switches to the second mode to create micro-arcs for additional heat and agitation, and can cycle between modes. This periodic switching allows the system to achieve high deposition rates through micro-arc pulses while controlling overall heat input by not maintaining continuous high-current operation.

Inventive Principle:

Principle #19Periodic action

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 allows for significant deposition rates with reduced heat input, achieving up to 35% less heat compared to traditional tandem MIG welding methods, enabling precise control over heat input and agitation to improve bead shape and penetration.

Implementation Method 1

a hot-wire power supply that outputs a first heating current during a first mode of operation and a second heating current during a second mode of operation

Methodology Applied

Scientific EffectResistive heating: Joule Heating

Implementation Method 2

switches the hot-wire power supply from the first mode of operation to the second mode of operation to create a micro-arc, which is created between the wire and the workpiece

Methodology Applied

Scientific EffectElectric arc: Electric Arc

Implementation Method 3

The second mode of operation provides at least one of an increased heat input to the molten puddle and an increased agitation of the molten puddle relative to the first mode of operation

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentUS9498838B2System and method of controlling heat input in tandem hot-wire applications

Publication Date: 2016.11.22 LINCOLN GLOBAL INC

AI summary

A system and method is provided. The system includes a high intensity energy source to create a molten puddle on a surface of a workpiece and a wire feeder that feeds a wire to the molten puddle via a contact tube. The system also includes a power supply that outputs a first heating current during a first mode of operation and a second heating current during a second mode of operation. The system further includes a controller that initiates the first mode of operation in the power supply to heat the wire to a desired temperature and switches the power supply from the first mode of operation to the second mode of operation to create a micro-arc. The second mode of operation provides at least one of an increased heat input to the molten puddle and an increased agitation of the molten puddle relative to the first mode of operation.