Two-Gun Solid Freeform Fabrication for Titanium Deposition

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Solution Overview

Problem

Current methods for manufacturing titanium and titanium alloy objects through solid freeform fabrication face challenges such as high material waste, long lead times, and inefficiencies in deposition rates due to the reactive nature of titanium, leading to issues like oxidation and distortion during the deposition process.

Innovation Solution

A two-gun system is employed, where a first welding gun preheats the base material, and a second welding gun melts a metal wire or powder, using combinations of laser devices, plasma arc welding torches, or electron beam devices to enhance deposition rates and control the deposition process, thereby reducing material waste and lead times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single welding gun is used for deposition, then the process is simpler, but the deposition rate is lower

Engineering Contradiction:
Improvedeposition rateVSAvoidwelding system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The welding process is segmented into two distinct functions performed by two separate welding guns: the first welding gun preheats the base material to an optimal temperature range, while the second welding gun performs the actual deposition of metallic material. This segmentation allows each gun to be optimized for its specific function, thereby increasing the overall deposition rate without excessive complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first welding gun performs preliminary heating of the base material before the second welding gun deposits the metallic material. This preliminary action of preheating the substrate improves the receptivity of the base material to the deposited material, enhances fusion, and increases the overall deposition rate by reducing the thermal shock and improving material flow

Inventive Principle:
Principle #10Preliminary action

2Productivity

If welding speed is increased to reduce lead time, then productivity improves, but oxidation and distortion increase

Engineering Contradiction:
Improvedeposition rateVSAvoidoxidation and distortion
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The first welding gun preheats the base material to an optimal temperature range before deposition begins. This preliminary heating reduces the thermal gradient between the deposited material and the substrate, minimizing thermal distortion while maintaining high deposition rates. It also prepares the surface for better metallurgical bonding

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs an inert or controlled atmosphere environment during the welding process to prevent oxidation of the metallic material and base material. This controlled environment allows for increased welding speeds without the harmful effects of oxidation that would otherwise occur at higher deposition rates

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

3Manufacturing precision

If preheating is applied to reduce distortion, then quality improves, but deposition rate decreases

Engineering Contradiction:
Improvedimensional accuracyVSAvoiddeposition rate
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The heating function is segmented from the deposition function and performed by a separate first welding gun. This allows continuous preheating to occur simultaneously with the deposition process performed by the second welding gun, maintaining dimensional accuracy through controlled preheating without sacrificing deposition rate

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first welding gun continuously preheats the base material throughout the deposition process, maintaining optimal temperature conditions for minimizing distortion. This continuous useful action of preheating occurs simultaneously with deposition, ensuring both quality and productivity are maintained

Inventive Principle:
Principle #20Continuity of useful 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 significantly increases deposition rates, reduces material waste, and improves the quality of the deposited layers by maintaining a stable molten pool, allowing for the efficient and distortion-free formation of titanium alloy objects with enhanced mechanical properties.

Implementation Method 1

a first welding gun for preheating the base material at a position at which the metallic material is to be deposited

Methodology Applied
Scientific EffectPreheating: Heating

Implementation Method 2

a second welding gun to melt a source of metal into droplets of metallic material that are deposited onto the preheated area of the base material

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

the droplets of metallic material solidifies and forms the three-dimensional object

Methodology Applied
Scientific EffectSolidification: Freezing

Implementation Method 4

using combinations of laser devices, plasma arc welding torches, or electron beam devices to enhance deposition rates

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 5

plasma arc welding torches

Methodology Applied
Scientific EffectPlasma arc welding: Electric Arc

Implementation Method 6

electron beam devices

Methodology Applied
Scientific EffectElectron beam heating: Electron Beam

Data Source

PatentEP3481579A1Method and arrangement for building metallic objects by solid freeform fabrication with two welding guns
Publication Date: 2019.05.15 NORSK TITANIUM AS

AI summary

Provided are a systems and methods for manufacturing objects by solid freeform fabrication, especially titanium and titanium alloy objects, wherein the deposition rate is increased by using two separate heat sources, one heat source for heating the deposition area on the base material and one heat source for heating and melting a metallic material, such as a metal wire or a powdered metallic material.