Composite Metal Powder Surface Layer for Laser Absorption

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The use of high power lasers for additive manufacturing with highly reflective metals like copper, gold, and silver is challenging due to back-reflection and thermal stress issues, leading to poor mechanical and electrical properties, and existing solutions like oxide films and carbon black cause additional problems.

Innovation Solution

A composite powder with a highly reflective metal core surrounded by a diffusion layer of metal nitride or carbide, which reduces reflectivity and enhances absorptivity, allowing for improved laser absorption and in-situ oxygen scavenging, resulting in high-quality, crack-free parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high power laser beams are used for additive manufacturing of highly reflective metals, then manufacturing capability is achieved, but back-reflection damages laser optics and thermal stresses degrade part quality

Engineering Contradiction:

Improvemanufacturing capabilityVSAvoidback-reflection and thermal stress

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating a non-uniform surface structure on the metal powder particles. A roughened surface layer is formed on highly reflective metal particles (copper, gold, silver) to increase surface area and light trapping, thereby improving laser absorption locally at the particle surface while maintaining the bulk metal properties for structural integrity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes color changes by modifying the surface optical properties of metal particles. The roughened surface structure changes the effective optical absorption characteristics of the metal particles, transforming them from highly reflective to laser-absorbent in the infrared wavelength range, enabling successful additive manufacturing

Inventive Principle:

Principle #32Color changes

2Use of energy by moving object

If oxide films are formed on copper powder particles to enhance laser absorptance, then laser absorption improves, but oxide evaporation at high temperatures creates pores and reduces mechanical properties

Engineering Contradiction:

Improvelaser absorptanceVSAvoidmelt pool stability and mechanical properties

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies parameter changes by controlling the oxidation state and thickness of the surface layer. Instead of forming thick oxide films that evaporate, the process creates a thin controlled oxide layer or surface roughness that provides sufficient laser absorption enhancement while remaining stable at melting temperatures, preventing pore formation

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If carbon black is applied to powder particles to assist absorption, then laser absorption improves, but excess carbon causes cracking and detrimental effects on mechanical properties

Engineering Contradiction:

Improvelaser absorptionVSAvoidmechanical properties

Core Design Contradiction:

Use of energy by moving objectVSStrength

Solution Approach 1:

The patent applies this principle by using a minimal amount of carbon or carbon-containing compounds only as long as needed for laser absorption enhancement during the additive manufacturing process. The carbon is present in such small quantities that it does not accumulate to cause cracking, and may even be partially consumed or transformed during the high-temperature processing

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent creates a composite structure on the metal particle surface, combining the base metal with a thin surface layer or coating that provides laser absorption. This composite approach allows the bulk metal to maintain its excellent mechanical properties while the surface layer provides the necessary optical absorption characteristics

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

The composite powder enables efficient laser absorption, reduces back-reflection, and improves mechanical and electrical properties of manufactured parts, with enhanced thermal conductivity and shelf life, allowing for repeatable use in additive manufacturing.

Implementation Method 1

The oxide film enhances the absorptance of an incident near-infrared laser beam at room temperature by the copper powder particles

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 2

the alloying element has diffused to the edge of the core element, thereby modifying a surface reflectivity of the powder

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 3

the nitride or carbide compound comprises the alloying element

Methodology Applied

Scientific EffectChemical Bonding: Chemical Bonding

Data Source

PatentEP3880387B1Copper, gold, or silver powder for powder bed additive manufacturing and method of manufacturing such powder

Publication Date: 2025.12.31 KATHOLIEKE UNIV LEUVEN

Figure 1~2
Figure 3a~3b
Figure 4~5a

AI summary

A composite powder comprising powder particles is disclosed for powder bed additive manufacturing. Each powder particle comprises a core element and a diffusion layer at least partially surrounding the core element. The core element comprises copper, gold or silver and an alloy element capable of forming a nitride, a carbide or a carbonitride. The diffusion layer comprises the alloy element and a nitride, carbide or carbonitride compound. The nitride, carbide or carbonitride compound comprises the alloy element.