Aluminum Electrical Contact With Creep-Resistant Mating Zone

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Solution Overview

Problem

Existing electrical contacts, particularly copper contacts, face challenges in providing stable mechanical and electrical connections with aluminum conductors, especially in applications requiring low weight and high mechanical stability, such as electric vehicles, where copper contacts are difficult to link with aluminum conductors due to weight and material cost issues.

Innovation Solution

An electrical contact featuring an aluminum body with a connecting portion made of aluminum or aluminum alloy, integrated with a contact spring that extends from a sleeve connected to the aluminum body, allowing for a form-fitting connection to an aluminum conductor, and a creep-resistant contact zone made of a noble metal like silver to ensure long-term contact quality without mechanical stress on the aluminum body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If copper contacts are used to connect electrical conductors, then mechanical stability and contact reliability are improved, but weight and material costs increase

Engineering Contradiction:
Improvecontact reliabilityVSAvoidcontact weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The contact is divided into two functional parts: an aluminum body for mechanical stability and weight reduction, and a copper contact zone for electrical conductivity and contact reliability. This segmentation allows each material to perform its optimal function without the drawbacks of using copper throughout the entire contact structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The contact combines aluminum and copper materials in a single component, with the copper contact zone integrated into the aluminum body. This composite structure leverages the high strength-to-weight ratio of aluminum and the superior electrical and contact properties of copper, resolving the contradiction between weight reduction and contact reliability.

Inventive Principle:
Principle #40Composite materials

2Strength

If copper contacts are used to connect aluminum conductors, then mechanical stability is improved, but linking difficulty and processing complexity increase

Engineering Contradiction:
Improvemechanical stabilityVSAvoidlinking ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The connecting portion of the contact body is made of aluminum, matching the material of the aluminum conductor. This material homogeneity eliminates galvanic corrosion issues and simplifies the linking process, as aluminum can be directly crimped or bonded to aluminum conductors without requiring special processing or intermediate materials.

Inventive Principle:
Principle #33Homogeneity

Solution Approach 2:

The contact is segmented into an aluminum body portion for easy linking with aluminum conductors and a copper contact zone for electrical performance. This allows the connecting portion to be optimized for ease of manufacture with aluminum conductors while maintaining overall mechanical stability through the copper reinforcement.

Inventive Principle:
Principle #1Segmentation

3Weight of moving object

If aluminum body is used for electrical contact, then weight and material costs are reduced, but mechanical stress resistance and contact stability worsen

Engineering Contradiction:
Improvecontact weightVSAvoidcontact stability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The contact combines aluminum and copper materials, with the copper contact zone providing enhanced mechanical strength and contact stability at the critical contact interface, while the aluminum body maintains weight reduction. The copper zone acts as a reinforcement that compensates for aluminum's lower mechanical properties where needed.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The copper material is strategically placed only in the contact zone where high mechanical stress resistance and contact stability are required, rather than throughout the entire contact. This local quality approach provides mechanical reinforcement exactly where needed while minimizing the overall weight penalty of using copper.

Inventive Principle:
Principle #3Local quality

4Weight of moving object

If aluminum body is used with standard contact zone, then weight reduction is achieved, but wear resistance and long-term contact quality worsen

Engineering Contradiction:
Improvecontact weightVSAvoidcontact durability
Core Design Contradiction:
Weight of moving objectVSDuration of action of stationary object

Solution Approach 1:

The contact uses a copper contact zone integrated into the aluminum body, where copper's superior wear resistance and creep resistance protect the contact interface during repeated mating and demating operations. This composite structure maintains the weight benefits of aluminum while ensuring long-term contact durability through copper's enhanced material properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The copper material is applied specifically to the contact zone surface and interface areas where wear and creep occur during operation. This localized application of wear-resistant material protects the critical contact surfaces while maintaining the overall lightweight aluminum construction, thereby extending the service life of the contact.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3621161B1Electrical contact for mating with a mating contact
Publication Date: 2023.10.04 TE CONNECTIVITY GERMANY GMBH
  • EP3621161B1 patent drawingFigure 1~2

AI summary

The invention relates to an electrical contact (1) for mating with a mating contact (16), comprising an aluminium body (2), extending along a longitudinal axis (L), made of aluminium or an aluminium alloy, said aluminium body (2) being provided with a connecting portion (4) for connection to an aluminium conductor (6), a contact zone (10), arranged on a surface (8) of the aluminium body (2), for electrical connection to the mating contact (16), and at least one contact spring (12) connected to the aluminium body (2) with a contact region (14) for contacting the mating contact (16), wherein the at least one contact spring (12) at least partially rests on the contact zone (10) and is formed from a material which is harder than the aluminium or aluminium alloy and wherein the contact zone (10) is formed from a material which is more creep-resistant than the aluminium or aluminium alloy. Furthermore, the invention relates to a contact arrangement (3) comprising an electrical contact (1) according to the invention and an aluminium conductor (6) connected in an integrally bonded and/or form-fitting manner to the connecting portion (4).