Multi-Material Bolt Element for Corrosion-Safe Sheet Attachment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bolt elements face issues with galvanic corrosion and mechanical stresses due to thermal expansion when attaching to workpieces with different materials, requiring deviations from optimal design to accommodate material hardness requirements.
Innovation Solution
A bolt element with a fastening section and a functional section made from different materials, where the fastening section is produced from a material that prevents galvanic corrosion and mechanical stresses, and the functional section is optimized for its intended function, with features like rotational fixation, security against rotation, and reshaping capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the functional element is produced from a single material that is different from the workpiece material, then the functional region can have optimal material properties (e.g., high hardness for threading), but galvanic corrosion and mechanical stresses due to thermal expansion occur
Solution Approach 1:
The functional element is divided into two distinct sections: a fastening section made from the same material as the workpiece (e.g., aluminum alloy) and a functional section made from a different material with optimal properties (e.g., steel with high hardness). This segmentation allows each section to have material properties optimized for its specific function while avoiding galvanic corrosion between dissimilar materials in contact with the workpiece.
Solution Approach 2:
Different sections of the functional element have different material qualities tailored to their specific requirements. The fastening section uses material matching the workpiece for compatibility, while the functional section (e.g., threaded region) uses material with superior hardness and strength properties. This local differentiation of material quality resolves the contradiction between needing hard functional surfaces and avoiding galvanic corrosion.
2Strength
If the functional element is produced from a single material that is harder than the workpiece material, then the functional region can have optimal material hardness, but mechanical stresses arise during thermal expansion leading to damage
Solution Approach 1:
The functional element is segmented into a fastening section made from the same material as the workpiece (matching thermal expansion characteristics) and a functional section made from harder material. This segmentation ensures that the fastening section expands and contracts with the workpiece during thermal cycles, preventing mechanical stresses and damage, while the functional section maintains its optimal hardness.
3Reliability
If the functional element is produced from the same material as the workpiece, then galvanic corrosion and thermal expansion stresses are avoided, but the functional region cannot achieve optimal material properties
Solution Approach 1:
The functional element employs local quality differentiation where the fastening section is made from material matching the workpiece (ensuring galvanic compatibility) while the functional section (e.g., threaded portion) is made from material with superior hardness and strength properties. This allows the functional region to achieve optimal material properties without compromising corrosion resistance at the interface with the workpiece.
4Reliability
If the functional element uses a single material optimized for fastening, then reliable attachment to the workpiece is achieved, but the functional region must deviate from optimal design
Solution Approach 1:
The functional element is segmented into a fastening section and a functional section, each with material optimized for its specific purpose. The fastening section uses material matching the workpiece for reliable attachment, while the functional section uses material with properties optimized for its intended function (e.g., high hardness for threading, corrosion resistance for chemical exposure). This segmentation enables both reliable fastening and optimal functional region design.
Solution Approach 2:
Different sections of the functional element have different material qualities: the fastening section has material properties optimized for bonding to the workpiece, while the functional section has material properties optimized for its specific function. This local quality differentiation allows the functional region to achieve optimal design without compromising fastening reliability.
Data Source
AI summary
The invention relates to a functional element, in particular to a bolt element, for attachment to a workpiece, in particular a sheet metal part. The functional element comprises a fastening section that has a reshaping section that can be reshaped to fasten the functional element to the workpiece, in particular wherein the reshaping section is a rivet section, and a functional section having a functional region, wherein the functional section is connected, in particular is rotationally fixedly connected, to the fastening section. The fastening section and the functional section are produced from different materials.