Friction Weld Pin Shank Solder Coating for Low Thermal Stress

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Solution Overview

Problem

Existing component connection methods using friction welding require high energy input, leading to potential deformation and reduced strength due to high temperatures, and often damage anti-corrosion layers, resulting in unreliable and weak connections.

Innovation Solution

A soldered connection is achieved by coating the connecting element's shank with soldering material, eliminating the need for melting the component materials, which reduces energy input and thermal stress, and using a surface structure with undercuts to retain solder material for enhanced bonding, allowing for a non-positive and positive connection with improved corrosion protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If friction welding is used to connect components with high contact force and rotation, then a material connection is achieved, but high temperatures cause deformation and reduce connection strength

Engineering Contradiction:
Improveconnection strengthVSAvoidprocess temperature
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

A flux-coating is applied to the shank of the connecting element as an intermediary substance. This flux-coating facilitates the material connection between the connecting element and components at lower temperatures by enabling diffusion processes without requiring the high temperatures of traditional friction welding, thus preventing deformation while achieving strong connections

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the chemical and physical parameters of the connection interface by introducing a flux-coating with specific compositional characteristics. This allows the connection process to occur at reduced temperatures by altering the interaction properties between the connecting element and components, avoiding the temperature-induced deformation problems of conventional friction welding

Inventive Principle:
Principle #35Parameter changes

2Strength

If high pressure force and high speeds are applied during friction welding, then a material connection is achieved, but the connecting element deforms and connection strength is impaired

Engineering Contradiction:
Improveconnection strengthVSAvoidconnecting element deformation
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The flux-coating serves as a mediator that enables material connection through diffusion processes at lower pressures and speeds. By coating the shank with this intermediary substance, the connecting element can form strong bonds without undergoing the high-stress conditions that cause deformation in traditional friction welding

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the process parameters by using a flux-coating that enables connection formation at reduced pressure and speed levels. This parameter modification prevents the connecting element from deforming while still achieving reliable material connections through the flux-facilitated diffusion process

Inventive Principle:
Principle #35Parameter changes

3Strength

If the contact surfaces are brought into a molten state during friction welding, then a material connection is achieved, but anti-corrosion layers are damaged

Engineering Contradiction:
Improvematerial connectionVSAvoidanti-corrosion protection
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the temperature parameter by using a flux-coating that enables material connection through diffusion at temperatures below the melting point of the base materials. This parameter change prevents the damage to anti-corrosion layers that occurs during high-temperature friction welding while still achieving reliable material connections

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The flux-coating acts as an intermediary that facilitates bonding without requiring the contact surfaces to reach molten states. This intermediary substance enables diffusion-based material connections at lower temperatures, preserving the integrity of anti-corrosion layers on the components

Inventive Principle:
Principle #24Intermediary (Mediator)

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 soldered connection provides a reliable, high-strength bond with reduced energy consumption, lower thermal stress, and enhanced corrosion protection, while minimizing the risk of deformation and overheating, allowing for faster process times and reduced production costs.

Implementation Method 1

the solder material is melted and can flow into the annular undercut (4a) on the underside of the connecting element head (4) and into the undercuts (3a) on the shaft (3)

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

a soldered connection is achieved by coating the connecting element's shank with soldering material

Methodology Applied
Scientific EffectSoldering: Soldering

Implementation Method 3

the connection element can have at least one undercut in which the solder material that is liquid during the joining process can collect

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 4

The high temperatures that occur create a friction-welded connection

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 5

in which the contact surfaces between the connecting element and the components are brought into a molten state

Methodology Applied
Scientific EffectFriction welding: Friction Welding

Implementation Method 6

A material connection is achieved in particular by diffusion processes at the contact surfaces between the solder material and the components and the connecting element

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP2741886B1Connection of at least two components resting against one another by means of a pin-like connecting element by friction welding
Publication Date: 2017.09.20 VOLKSWAGEN AG
  • EP2741886B1 patent drawingFigure 1
  • EP2741886B1 patent drawingFigure 2
  • EP2741886B1 patent drawingFigure 3

AI summary

The invention relates to a connection of at least two components (5, 6) resting against one another by means of a pin-like connecting element (1) having a shank (3), which merges into a point (2) and has a widened head (4) for driving in the connecting element (1) under the application of pressure and rotation, wherein the firm connection is created via frictional heating and local deformation of the component materials. The shank (3) is covered with a coating made of a solder material (11) which forms a solder connection between the components (5, 6) and the connecting element (1).