Composite Vane Shield Attachment via Controlled Heating Cycle
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Solution Overview
Problem
Current methods for manufacturing composite material vanes for aircraft turbomachines face challenges in ensuring optimal attachment of metal shields to the blades, particularly in terms of adhesive polymerization, resin injection, and maintaining mechanical properties.
Innovation Solution
A method involving a specific mould heating cycle with successive temperature rises and maintenance stages, where the resin is injected during the second temperature rise, ensuring the adhesive and resin viscosities are significantly different, allowing for controlled attachment and polymerization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the shield is attached by gluing after polymerization, then the attachment can be performed separately, but additional heat treatment equipment and surface preparation are required
Solution Approach 1:
The patent merges the shield attachment process with the resin injection and polymerization process. The adhesive is applied to the preform before resin injection, and both the adhesive and resin are polymerized simultaneously during the same heating cycle, eliminating the need for separate gluing operations and additional heat treatment equipment.
Solution Approach 2:
The adhesive is applied to the preform in advance, before resin injection. This preliminary action allows the adhesive to be in position and ready for simultaneous polymerization with the resin, eliminating the need for subsequent surface preparation and separate attachment operations.
2Productivity
If the shield is attached by co-moulding with fibre preform, then the attachment is integrated into injection step, but controlling adhesive polymerization and resin injection simultaneously is difficult
Solution Approach 1:
The patent uses a multi-stage heating cycle with periodic temperature increases. The cycle includes an initial heating phase, a first maintenance phase, a second heating phase, and a second maintenance phase. This periodic action allows controlled progression of adhesive polymerization and resin polymerization at different rates, ensuring both materials achieve proper curing without interfering with each other.
Solution Approach 2:
The patent changes temperature parameters during the manufacturing process. By controlling the temperature progression through multiple heating and maintenance phases, the viscosity and polymerization rate of both adhesive and resin are controlled. The temperature is maintained within specific ranges during different phases to ensure proper material behavior and final properties.
3Ease of operation
If the resin is injected at high temperature to reduce viscosity, then the resin flows better, but the adhesive may polymerize prematurely
Solution Approach 1:
The heating cycle includes distinct phases where temperature is increased in steps rather than continuously. During the initial and first maintenance phases, the temperature is controlled to allow resin injection without causing premature adhesive polymerization. The second heating phase then raises the temperature further to complete the polymerization of both materials, ensuring proper timing and material properties.
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 ensures a robust and reliable attachment of the metal shield to the blade, maintaining the mechanical properties of the composite material while simplifying the manufacturing process by eliminating the need for additional heat treatment equipment and surface preparation.
Implementation Method 1
the mould is heated in a cycle comprising: an initial temperature rise from a temperature T1 to a temperature T2, possibly a first temperature maintenance stage T2 for a predetermined period, a second temperature rise from the temperature T2 to a temperature T3, and a second temperature maintenance stage T3 for a predetermined period
Implementation Method 2
the injected resin passes successively from the liquid state to the gelled state and finally to the solid state
Implementation Method 3
the resin is injected in a liquid state by maintaining a pressure on the injected resin
Data Source
AI summary
Method for manufacturing a blade made of a composite material for a turbomachine, in particular of an aircraft, including steps of: a) arranging a preform produced by three-dimensional weaving of fibres within a mould, a polymerisable adhesive being inserted between a shield and an edge of the preform, b) closing and heating the mould, then injecting the polymerisable resin into the mould, wherein the mould is heated according to a cycle including increases in temperature from T1 to T2, then from T2 to T3, and in that the resin is injected in step b) during or just before the increase in temperature from T2 to T3, the temperature T2 being selected so that the viscosity of the adhesive is greater than the viscosity of the resin.