Aluminizing Sequence for Smoother Additive Manufactured Surfaces

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Additive manufacturing processes often result in articles with unduly high surface roughness due to incomplete leveling of melted and solidified powder feed-stocks, which can hinder component functionality, fluid flow, and mechanical properties.

Innovation Solution

A method involving aluminizing an initial surface at a first temperature to form a first aluminized layer and sublayer, then removing portions of these layers at successively lower temperatures to form a processed surface with reduced roughness, iteratively if necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If additive manufacturing processes are used to fabricate components, then complex three-dimensional parts can be manufactured with reduced cost and increased throughput, but the surface roughness becomes unduly high due to incomplete leveling of melted and solidified powder feed-stocks

Engineering Contradiction:
ImprovethroughputVSAvoidsurface roughness
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The surface treatment process is segmented into multiple discrete steps: aluminizing at first temperature to form first aluminized layer, removing first aluminized layer, aluminizing at second temperature to form second aluminized layer, and removing second aluminized layer. This segmentation allows each step to address specific aspects of surface roughness reduction systematically

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The process utilizes parameter changes by varying the temperature between aluminizing steps (first temperature vs. second temperature) to control the formation characteristics of different aluminized layers. This parameter variation enables differential removal strategies that progressively reduce surface roughness to below 5 micrometers Ra

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If high surface roughness is present on external surfaces or internal channel walls, then component fabrication is simplified, but component functionality is hindered where fluid flow plays a role

Engineering Contradiction:
Improvefabrication simplicityVSAvoidcomponent functionality
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

Temperature parameters are changed between aluminizing steps to control layer formation and removal characteristics, enabling precise control over final surface roughness to meet functional requirements for fluid flow while maintaining manufacturing feasibility

Inventive Principle:
Principle #35Parameter changes

3Loss of substance

If high surface roughness is present on component surfaces, then material removal during manufacturing is reduced, but mechanical properties deteriorate due to promoted fatigue crack initiation

Engineering Contradiction:
Improvematerial removalVSAvoidmechanical properties
Core Design Contradiction:
Loss of substanceVSStrength

Solution Approach 1:

The aluminizing and removal process is applied preliminarily to the component surface before final assembly or use. This preliminary action reduces surface roughness in advance, preventing fatigue crack initiation and preserving mechanical properties without requiring additional material removal operations later

Inventive Principle:
Principle #10Preliminary 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

The method significantly reduces surface roughness by up to 95% of the initial value, improving the functionality and mechanical properties of components.

Implementation Method 1

removing at least a portion of the first aluminized layer by acid etching to expose the sublayer

Methodology Applied
Scientific EffectAcid etching:

Implementation Method 2

heat-treating the coated surface at a first temperature to form a first aluminized layer and a sublayer

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 3

heat-treating the coated sublayer at a second temperature to form a second aluminized layer

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Data Source

PatentEP3492623B1Method for reducing surface roughness
Publication Date: 2025.11.05 GENERAL ELECTRIC CO
  • EP3492623B1 patent drawingFigure 1
  • EP3492623B1 patent drawingFigure 2~3
  • EP3492623B1 patent drawingFigure 4~7

AI summary

A surface of an article is modified by aluminizing an initial surface at a first temperature to form a first aluminized layer and a sublayer, removing at least a portion of the first aluminized layer, aluminizing the sublayer at a second temperature to form a second aluminized layer, and finally removing at least a portion of the second aluminized layer to form a processed surface. The second temperature is less than the first temperature and a roughness of the processed surface is less than the roughness of the initial surface.