Friction Squeeze Welding Disc Element for Metal Sheet Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for joining flat or sheet-like workpieces, such as fusion and pressure welding, face limitations including oxide layer issues, inconsistent bonding strengths, and complexity in heat distribution, particularly with pin-shaped friction elements and the need for reliable, cost-effective, and simple machinery for various materials like aluminum and copper.
Innovation Solution
A method using a rotating disc-shaped friction element pressed against the surface of overlapping metal sheets to create a pressure-welded connection, allowing for continuous or punctiform welds, with the friction element's rotation and contact pressure causing local heating and plasticization, effectively breaking through oxide layers and ensuring consistent bonding across the contact surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a pin-shaped friction element is used for heating and joining workpieces, then local heating and plasticization can be achieved, but the contact area has different relative speeds leading to inconsistent bonding strengths
Solution Approach 1:
The patent replaces the pin-shaped friction element with a disc-shaped friction element. The disc shape provides a curved surface where all contact points have the same relative speed with respect to the workpiece, eliminating the speed variation inherent in pin-shaped elements. This curvature ensures uniform friction heating and consistent plasticization across the entire contact area, resulting in uniform bonding strength throughout the joint.
2Strength
If additional materials are introduced into the joining area, then welding can be achieved, but the process becomes more complex and requires additional handling
Solution Approach 1:
The friction element itself serves dual purposes: it generates the heat needed for plasticization through friction and simultaneously acts as the pressing element that forces the plasticized materials together. The process uses only the materials from the workpieces themselves, with no additional filler materials required. This self-service approach simplifies the overall process while achieving strong joints through pure friction-based plasticization and pressure welding.
3Strength
If friction welding is used to join workpieces, then joining can be achieved, but oxide layers between surfaces cannot be removed resulting in poor connection quality
Solution Approach 1:
The patent converts the harmful effect of oxide layers into a beneficial process feature. The intense friction heating and plasticization caused by the disc-shaped friction element actually help to break through and remove oxide layers from the workpiece surfaces. The plasticized state of the materials allows the oxide layers to be disrupted and excluded during the pressing phase, resulting in clean metal-to-metal contact and strong joints despite the initial presence of oxides.
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 provides reliable, cost-effective, and efficient joining of metals and ceramics with consistent bonding quality, capable of producing continuous welds, stitched seams, or point joints, without the need for additional materials or protective gases, and can handle materials like aluminum and copper with ease, while minimizing heat influence and machine effort.
Implementation Method 1
the friction element being pressed against the surface by means of a contact pressure... the friction element's rotation and contact pressure causing local heating and plasticization
Implementation Method 2
the friction element's rotation and contact pressure causing local heating and plasticization... brought to its softening temperature and pressed together by a contact pressure, resulting in a welded joint
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a method for joining essentially flat or metal sheet-type workpieces (1, 2). In said method, the regions of the workpieces (1, 2) to be joined are placed on top of one another, the surface of one (1) of the workpieces is brought in contact with a rotating frictional element (3), and the frictional element (3) is pressed against the surface using a certain contact pressure (4).