Deformable Core Tooling for Brazing Large Metal Parts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional brazing methods are inefficient and costly for manufacturing large-sized metal parts, particularly those with high thermal expansion coefficients like Inconel 625, due to high thermal inertia and lengthy cycle times, and have unreliable sealing systems in gas pressurization tools.
Innovation Solution
A method involving a tooling assembly with a counter-form and a tight, deformable core comprising inner and outer skins, a honeycomb structure, and brazing elements, where the core is sealed by welding lids to the inner skin, allowing direct gas introduction and reducing thermal inertia by eliminating the need for a central cask, thus shortening assembly and sealing times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal tooling is used for brazing large-sized parts, then the part can be assembled, but the thermal inertia becomes very high and cycle time becomes extremely long
Solution Approach 1:
The tooling is segmented into a deformable core with inner and outer skins instead of a solid metal mass. The core can be deformed by gas pressure to create the necessary plating action, eliminating the need for heavy solid metal tooling while maintaining assembling capability.
Solution Approach 2:
Gas pressure is introduced into the deformable core to cause expansion and plating of the part. This pneumatic mechanism replaces the thermal expansion of heavy metal tooling, achieving the same brazing effect with dramatically reduced thermal inertia and cycle time.
2Ease of operation
If a central cask is used for gas introduction in pressurization tools, then gas can be introduced, but the thermal inertia increases and assembly time lengthens
Solution Approach 1:
The central cask is completely removed from the tooling design. Gas introduction is achieved by deforming the core itself through controlled gas pressure application, eliminating the intermediate cask structure and its associated assembly and thermal inertia penalties.
Solution Approach 2:
The gas introduction function is merged with the deformable core structure. The core serves both as the pressure transmission medium and as the plating mechanism, eliminating the need for separate cask and tooling components.
3Reliability
If conventional brazing methods are used for parts with high thermal expansion coefficients, then the parts can be joined, but the process becomes inefficient and costly
Solution Approach 1:
The process changes from thermal expansion-based plating to gas pressure-based plating. By changing the fundamental mechanism from thermal to pneumatic, the method becomes efficient for materials with high thermal expansion coefficients like Inconel 625, improving productivity without sacrificing joining capability.
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 significantly reduces thermal inertia and cycle time, enabling efficient manufacturing of large metal parts like inner fixed structures of turbojet engine nacelles and ejection cones, while ensuring a reliable sealing system.
Implementation Method 1
heating the tooling assembly so as to cause successively: the plating of the core against the counter-form by expansion of said pressurized gas
Implementation Method 2
the brazing of the honeycomb structure and of the inner and outer skins
Data Source
AI summary
A manufacturing method for a metal part uses a tooling assembly. The tooling assembly includes a counter-form and a deformable core which includes inner and outer skins, a honeycomb structure positioned between the inner and outer skins, and a brazing material interposed between the honeycomb structure and the inner and outer skins. In particular, the core is closed by a lid equipped with ducts through which a gas is introduced. The manufacturing method includes the following steps: positioning the tooling assembly in a vacuum furnace; introducing a pressurized gas directly inside an inner skin of the core of the tooling assembly; purging the pressurized gas from an inner portion of the inner skin of the tooling assembly; and dismounting the tooling assembly so as to extract a metal part manufactured.