Titanium Plate Surface Roughness for Coating Adhesion

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Solution Overview

Problem

Existing titanium plates face challenges in achieving sufficient adhesiveness with surface coating layers while maintaining workability, and existing methods often increase treatment costs.

Innovation Solution

Controlled cold rolling conditions, including strong reduction and use of dull rolls in specific passes, to create uniform asperities on the titanium surface, enhancing adhesiveness without compromising workability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional cold rolling is performed on titanium plate, then workability is maintained, but adhesiveness with surface coating layer is insufficient

Engineering Contradiction:
ImproveworkabilityVSAvoidadhesiveness with surface coating layer
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention changes the surface parameters of the titanium plate by controlling cold rolling conditions (reduction ratio of 5-20% in final passes, use of dull rolls with Ra 0.5-5.0 μm) to create asperities with specific characteristics (density 10-100 pieces/mm², average spacing 10-50 μm). This transforms the smooth surface into one with controlled roughness that enhances coating adhesiveness while preserving bulk material workability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention performs preliminary surface modification through controlled cold rolling before surface coating is applied. The asperities are formed in advance during the rolling process, creating a pre-prepared surface structure that ensures good adhesiveness for subsequent coating operations without requiring additional surface treatment steps.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If strong reduction or dull roll is used in cold rolling to improve adhesiveness, then asperities are formed on surface, but cracks may occur reducing workability

Engineering Contradiction:
Improveadhesiveness with surface coating layerVSAvoidworkability
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention optimizes the reduction ratio parameter to a specific range (5-20% in final passes) and controls the surface roughness of rolls (Ra 0.5-5.0 μm). These parameter changes create asperities sufficient for coating adhesiveness while staying below the threshold that would cause harmful cracks, thus balancing adhesiveness improvement with workability preservation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses the roll surface pattern as a template to copy asperities onto the titanium plate surface. By controlling the roll surface roughness within specific ranges, the desired asperity pattern is replicated on the plate without applying excessive stress that would cause cracking.

Inventive Principle:
Principle #26Copying

3Manufacturing precision

If titanium carbide is formed on surface to improve adhesiveness, then anchoring effect is enhanced, but surface hardness increases reducing formability

Engineering Contradiction:
Improveadhesiveness with surface coating layerVSAvoidformability
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The invention creates local asperities on the surface through controlled cold rolling without forming extensive titanium carbide layers. The asperities provide localized anchoring points for coating adhesion while the bulk material maintains its original properties and formability. This localized surface modification avoids the trade-off between adhesiveness and formability.

Inventive Principle:
Principle #3Local quality

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 results in a titanium plate with improved adhesiveness to surface coating layers and maintained workability, achieved through controlled asperity distribution and carbon content, reducing the risk of cracks and enhancing anchoring effects.

Implementation Method 1

titanium forms a passive film of TiO2 on a surface thereof

Methodology Applied
Scientific EffectPassive film formation: Oxidation

Implementation Method 2

Controlled cold rolling conditions, including strong reduction and use of dull rolls in specific passes, to create uniform asperities on the titanium surface

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 3

by an anchoring effect provided by the layer, adhesiveness with a carbon film to be formed thereafter is improved

Methodology Applied
Scientific EffectCarbon diffusion: Diffusion

Data Source

PatentEP3778046B1Titanium plate
Publication Date: 2025.08.13 NIPPON STEEL CORPORATION
  • EP3778046B1 patent drawingFigure 1~2
  • EP3778046B1 patent drawingFigure 3~4
  • EP3778046B1 patent drawing

AI summary

A titanium plate includes a chemical composition of industrial pure titanium, in which an arithmetic mean roughness Ra of a surface is 0.05 µm or more and 0.40 µm or less, the surface has titanium carbide regarding which a ratio between a total sum of integrated intensities Ic derived from the titanium carbide and a total sum of integrated intensities Im of all diffraction peaks derived from the titanium carbide and titanium obtained from X-ray diffractometry ((Ic/Im) × 100) is 0.8% or more and 5.0% or less, a number density of asperities on the surface is 30 to 100 pieces/mm, and an average spacing of the asperities is 20 µm or less.