Nickel-Iron Alloy Electroformed Part for Timepiece Springs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electroformed nickel parts exhibit poor creep resistance and stress relaxation properties, making them unsuitable for spring components due to instability and brittleness when iron content exceeds 25%, leading to dimensional issues and reduced strength.
Innovation Solution
A nickel-iron alloy with an iron content of 5-25% by mass, featuring a roughly layered structure with an inclined iron content gradient and face-centered cubic lattice, where nickel atoms are partially substituted by iron, and crystal grains have an average diameter of 50 nm or less, enhancing mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If iron content is increased to improve creep resistance and stress relaxation resistance, then mechanical properties are improved, but electroforming stability deteriorates and brittleness increases when iron content exceeds 25%
Solution Approach 1:
The patent optimizes the iron content parameter to within 25% by mass, preventing the formation of body-centered cubic lattice phase while maintaining improved creep and stress relaxation resistance. This parameter control resolves the contradiction by staying within the stable electroforming range while achieving the desired mechanical property enhancements.
Solution Approach 2:
The patent creates a nickel-iron alloy composite material that combines the advantages of both nickel (electroforming stability) and iron (creep and stress relaxation resistance). The composite structure allows the material to exhibit both electroforming stability and improved mechanical properties simultaneously.
2Strength
If iron content is increased to improve mechanical properties, then strength and creep resistance are enhanced, but brittleness increases and dimensional stability decreases
Solution Approach 1:
The patent controls iron content to maximum 25% by mass and maintains crystal grain size of 50 μm or less, optimizing the balance between strength improvement and brittleness prevention. This dual parameter control resolves the contradiction by achieving enhanced mechanical properties while avoiding excessive brittleness.
Solution Approach 2:
The patent creates a layered structure with alternating high-iron and low-iron content layers, where each layer has different local compositions optimized for specific functions. The high-iron layers provide strength and creep resistance, while the low-iron layers maintain ductility and reduce brittleness, resolving the contradiction through spatial differentiation of material properties.
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 solution provides excellent creep resistance, stress relaxation resistance, and spring properties, enabling high-precision electroformed parts suitable for applications like timepieces, with improved mechanical strength and dimensional stability.
Implementation Method 1
a production method by an electroforming method is being adopted
Implementation Method 2
an electroformed part composed of a nickel-iron alloy that is constituted by Ni, Fe, and unavoidable impurities
Data Source
AI summary
An object of the present invention is to provide an electroformed part favorable for an assembly part of a timepiece or the like and a timepiece using the same. The present invention relates to an electroformed part, which is an electroformed part composed of a nickel-iron alloy constituted by nickel, iron, and unavoidable impurities, containing iron at 5 to 25% by mass, and having a roughly layered form portion in which a stacked form portion having an inclined iron content in a thickness direction is repeatedly stacked a plurality of times. It is preferred that the stacked portion is constituted by crystal grains having an average grain diameter of 50 nm or less.