Fluid Fitting Friction Welding for Low-Porosity Sealed Joints
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Solution Overview
Problem
Conventional welding processes for fluid systems, such as GTAW-P, result in a large weld surface area, heat-affected zone, and susceptibility to contamination, leading to porosity and reduced material properties, while also requiring shielding gases and filler metals, which are not ideal for creating strong, reliable connections.
Innovation Solution
The use of friction welding, a low-temperature solid-state process that generates heat through friction and forging, eliminating the need for filler metals and shielding gases, and producing a small heat-affected zone with high strength welds by aligning and compressing workpieces to create a metal-to-metal seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional welding processes (GTAW-P) are used to permanently connect fluid elements, then the fluid elements are connected together, but the weld surface area is large, heat-affected zone is large, and susceptibility to contamination increases leading to porosity and reduced material properties
Solution Approach 1:
The patent replaces thermal welding processes (GTAW-P) with friction welding, a solid-state mechanical process. The friction welding process uses mechanical friction and forging pressure to join materials without melting, thereby eliminating the harmful effects of thermal processes such as large heat-affected zones, contamination susceptibility, and porosity formation, while maintaining strong welds.
Solution Approach 2:
The patent changes the fundamental parameters of the welding process by transitioning from high-temperature thermal welding to low-temperature solid-state friction welding. This parameter change reduces the heat-affected zone, eliminates contamination pathways, and prevents porosity formation while achieving strong metallurgical bonds between fluid elements.
2Strength
If conventional welding processes (GTAW-P) are used to permanently connect fluid elements, then the fluid elements are connected together, but shielding gases and filler metals are required
Solution Approach 1:
The patent extracts and eliminates the need for shielding gases and filler metals from the welding process by using friction welding. This solid-state process joins materials through friction heat and forging pressure alone, removing the complexity associated with gas shielding systems and filler material handling while producing strong, clean welds.
Solution Approach 2:
The friction welding process is self-sufficient, generating its own heat through friction between the workpieces and using the applied forging pressure to create the bond. This eliminates the need for external shielding gases and filler metals, simplifying the overall process and reducing equipment complexity.
3Strength
If conventional welding processes are used, then fluid elements are permanently connected, but energy consumption and material waste increase
Solution Approach 1:
The patent changes the thermal parameters of the welding process by using solid-state friction welding instead of high-temperature fusion welding. This reduces energy consumption by avoiding the complete melting of materials and the subsequent cooling cycle, while still achieving strong metallurgical bonds through friction heat and forging pressure.
Solution Approach 2:
The patent converts the potentially harmful friction heat, which could cause distortion or damage, into a beneficial bonding mechanism. By controlling the friction process and applying forging pressure, the friction heat is used to soften the material surfaces and facilitate metallurgical bonding, transforming what could be a harmful thermal effect into a useful joining mechanism.
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
Friction welding achieves a strong, low-stress weld with no porosity, maintaining material properties, and reducing energy consumption and waste, while allowing for the joining of dissimilar metals and complex shapes, enhancing the reliability and efficiency of fluid system connections.
Implementation Method 1
a low-temperature solid-state process that generates heat through friction
Implementation Method 2
generates heat through friction and forging, eliminating the need for filler metals and shielding gases
Data Source
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AI summary
A method of friction welding a workpiece to a fluid element includes the step of placing a workpiece weld surface in contact with a fluid element weld surface. The workpiece weld surface is driven in a predetermined pattern along the fluid element weld surface. Pressure is applied between the workpiece weld surface and the fluid element weld surface to produce friction and heat sufficient to raise the temperature of the weld surfaces to welding temperature. A weld bond is formed by stopping the driving of the workpiece weld surface while applying the pressure between the weld surfaces. Before and/or after the weld bond is formed, at least a portion of the workpiece is machined to form at least a portion of a fluid fitting configured to receive and sealingly attach to a pipe in a non-leaking manner to convey a flow of fluid therethrough.