Mo and W Additive Components With Low-Oxygen Crack-Free Structure

Solution Overview

Problem

Components made from molybdenum (Mo), tungsten (W), or their alloys produced via additive manufacturing methods, such as selective laser melting, face issues with high defect frequency, low fracture toughness, poor surface quality, and low density due to the balling effect and intercrystalline fracture characteristics caused by high oxygen content and thermally induced stresses.

Innovation Solution

The use of a high-energy beam to fuse individual powder particles of Mo, W, or their alloys with an oxygen content of not more than 0.1 at% and a carbon content of at least 0.08 at%, which reduces the balling effect, enhances grain boundary strength, and promotes transcrystalline fracture characteristics, thereby improving fracture toughness and surface quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If additive manufacturing methods are used to produce components from Mo, W or their alloys, then geometric flexibility and manufacturing cost are improved, but defect frequency increases and fracture toughness decreases

Engineering Contradiction:

Improvegeometric flexibilityVSAvoiddefect frequency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying the chemical composition parameters of the starting powder, specifically limiting oxygen content to ≤0.1 at% and controlling carbon content to ≥0.08 at%. This compositional parameter change fundamentally alters the material behavior during additive manufacturing, reducing oxidation-related defects and improving fracture toughness while maintaining the geometric flexibility benefits of additive manufacturing.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes composite material principles by creating a controlled carbon-molybdenum or carbon-tungsten system where carbon acts as a beneficial additive rather than an impurity. The controlled carbon content (≥0.08 at%) forms carbides that strengthen grain boundaries and improve fracture characteristics, transforming the material from a simple metal to a controlled composite system that resolves the reliability issue.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If additive manufacturing methods are used to produce components from Mo, W or their alloys, then geometric flexibility is improved, but surface quality deteriorates

Engineering Contradiction:

Improvegeometric flexibilityVSAvoidsurface quality

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by modifying the chemical composition parameters of the starting powder, specifically limiting oxygen content to ≤0.1 at% and controlling carbon content to ≥0.08 at%. This compositional parameter change fundamentally alters the material behavior during additive manufacturing, reducing oxidation-related defects and improving fracture toughness while maintaining the geometric flexibility benefits of additive manufacturing.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If additive manufacturing methods are used to produce components from Mo, W or their alloys, then geometric flexibility is improved, but density decreases

Engineering Contradiction:

Improvegeometric flexibilityVSAvoiddensity

Core Design Contradiction:

Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes by modifying the chemical composition parameters of the starting powder, specifically limiting oxygen content to ≤0.1 at% and controlling carbon content to ≥0.08 at%. This compositional parameter change fundamentally alters the material behavior during additive manufacturing, reducing oxidation-related defects and improving fracture toughness while maintaining the geometric flexibility benefits of additive manufacturing.

Inventive Principle:

Principle #35Parameter changes

4Shape

If high oxygen content powder is used in additive manufacturing, then balling effect increases, but fracture toughness decreases

Engineering Contradiction:

Improveballing effectVSAvoidfracture toughness

Core Design Contradiction:

ShapeVSStrength

Solution Approach 1:

The patent applies parameter changes by modifying the chemical composition parameters of the starting powder, specifically limiting oxygen content to ≤0.1 at% and controlling carbon content to ≥0.08 at%. This compositional parameter change fundamentally alters the material behavior during additive manufacturing, reducing oxidation-related defects and improving fracture toughness while maintaining the geometric flexibility benefits of additive manufacturing.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes composite material principles by creating a controlled carbon-molybdenum or carbon-tungsten system where carbon acts as a beneficial additive rather than an impurity. The controlled carbon content (≥0.08 at%) forms carbides that strengthen grain boundaries and improve fracture characteristics, transforming the material from a simple metal to a controlled composite system that resolves the reliability issue.

Inventive Principle:

Principle #40Composite materials

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 reduces defect frequency, particularly crack formation, and enhances fracture toughness and surface quality by minimizing oxygen-induced intercrystalline fractures and promoting a transcrystalline fracture mode, resulting in components with improved density and mechanical properties.

Implementation Method 1

selective laser melting (SLM), in which powder applied layer by layer is locally sintered by means of a laser beam, selective laser melting (SLM) and selective electron beam melting (SEBM), in which powder applied layer by layer is locally melted

Methodology Applied

Scientific EffectLaser melting: Melting

Implementation Method 2

selective electron beam melting (SEBM), in which powder applied layer by layer is locally melted

Methodology Applied

Scientific EffectElectron beam melting: Electron Beam

Implementation Method 3

a carbon content of at least 0.08 at%, which reduces the balling effect, enhances grain boundary strength

Methodology Applied

Scientific EffectGrain boundary strengthening: Grain Boundary Strengthening

Implementation Method 4

an oxygen content of not more than 0.1 at %, and a carbon content of at least 0.08 at%, which reduces the balling effect, enhances grain boundary strength, and promotes transcrystalline fracture characteristics

Methodology Applied

Scientific EffectFracture mechanics: Fracture Mechanics

Data Source

PatentUS11565322B2Additively manufactured component and production method therefor

Publication Date: 2023.01.31 PLANSEE SE

AI summary

A component includes a multiplicity of individual powder particles of Mo, a Mo-based alloy, W or a W-based alloy that have been fused together to give a solid structure by a high-energy beam via an additive manufacturing method. The component has an oxygen content of not more than 0.1 at %. An additive manufacturing method includes producing the powder via the melt phase and providing a carbon content in the region of not less than 0.15 at %. The components are crack-free and have high grain boundary strength.