Zirconia-Titanium Brazed Assembly for Durable Watch Casings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The assembly of ceramic components with metal alloy components in watchmaking is challenging due to the difficulty in achieving durable bonds without mechanical constraints or polymer adhesives, which often result in weakened components or lack of durability.

Innovation Solution

A method of direct brazing between zirconia-based ceramic and titanium alloy components is employed, involving the creation of recesses in the ceramic substrate, deposition of solder, and precise positioning of the metal alloy component, followed by heating under controlled atmosphere to achieve fusion and bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If chasing, bonding (polymer adhesive), or screwing techniques are used to assemble ceramic components with metal alloy components, then assembly can be achieved, but the components are weakened or durability is not guaranteed

Engineering Contradiction:
Improvedurability of assemblyVSAvoidstrength of components
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the bonding mechanism by using brazing technology with specific temperature parameters (heating to brazing temperature to melt the filler metal) and controlled atmosphere parameters (vacuum or protective gas) to achieve strong, durable bonds without mechanical constraints or polymer adhesives that weaken components

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a filler metal as an intermediary material between the ceramic component and metal alloy component. This filler metal acts as a mediator that creates a strong bond between the two dissimilar materials, replacing weak polymer adhesives or mechanical fastening systems

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If direct brazing is used between zirconia-based ceramic and titanium alloy components, then durable assembly with better mechanical and thermal properties is achieved, but additional process steps (creating recesses, depositing solder) are required

Engineering Contradiction:
Improvedurability of assemblyVSAvoidcomplexity of brazing process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary actions by creating recesses in the ceramic component and depositing solder on the bearing surfaces before the actual brazing operation. These preparatory steps ensure proper filler metal distribution and bonding, achieving durable assembly despite the additional process steps

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

This method allows for a durable and high-quality assembly between titanium and ceramic components, providing better mechanical and thermal properties compared to conventional techniques, while controlling production costs by eliminating the need for thin-layer metallization.

Implementation Method 1

heating under controlled atmosphere to achieve fusion and bonding

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

heating under controlled atmosphere to achieve fusion and bonding

Methodology Applied
Scientific EffectOxidation prevention: Oxidation

Data Source

PatentEP3666745B1Method for brazing titanium alloy components with ceramic components made of zirconia for timepieces or jewellery
Publication Date: 2025.06.18 COMADUR
  • EP3666745B1 patent drawingFigure 1~8
  • EP3666745B1 patent drawingFigure 9~14

AI summary

A brazing process for a first ceramic component (10) and a second metal alloy component (20) to create a structural or casing element (100) for a watch, is used. For the first component (10), a zirconia-based ceramic is chosen, and for the second component (20), a titanium alloy. A first housing (4) is made in the heart of the first component (10), set back from a first surface (1) in a junction zone (3) with a second surface (2) of the second component (20). Brazing (5) is deposited on this first surface (1) and in each housing (4). The second surface (2) is positioned in accordance with the first surface (1) to form an assembly. The assembly is heated under a controlled atmosphere beyond the melting temperature of the brazing (5) to perform the brazing at the junction zone (3).