HIP Can and Skin Component Bonding for Hollow Metal Parts
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Solution Overview
Problem
Conventional powder Hot Isostatic Pressing (HIP) processes face challenges in manufacturing complex and hollow metal parts due to thermal expansion mismatches between can materials and powders, and difficulties in forming and removing can material from internal regions.
Innovation Solution
A method involving a HIP can and skin component made from metals with similar thermal expansion coefficients, where the HIP can is welded to the skin and filled with powder, allowing pressure communication through vents, eliminating the need for can removal post-processing, and using electron beam welding for a secure bond.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If steel cans are used with titanium powder, then the can provides structural support during HIP processing, but the mismatched thermal expansion coefficients cause manufacturing defects
Solution Approach 1:
The patent applies homogeneity by selecting can material with thermal expansion coefficients matching the powder material (e.g., Invar for titanium powder, stainless steel for Inconel powder). This material compatibility ensures uniform thermal expansion behavior during HIP processing, eliminating the manufacturing defects caused by mismatched expansion rates while maintaining can structural support.
2Ease of manufacture
If conventional HIP cans are used, then the process is simple, but hollow-section parts are extremely hard to manufacture due to difficulties in forming moulds and removing can material
Solution Approach 1:
The patent inverts the conventional approach by making the can itself the forming mould. Instead of using separate external moulds to shape hollow parts and then removing can material, the can's internal cavity directly defines the hollow part geometry. The powder is packed against the can's internal surface, and during HIP processing, the powder bonds to the can wall, eliminating the need for mould removal and post-processing.
Solution Approach 2:
The patent merges the can structure with the final part by bonding the powder to the can wall during HIP processing. The can transitions from a temporary container to an integral part of the final component, combining the forming function with the structural support function in a single integrated solution.
3Manufacturing precision
If the can is removed after HIP processing, then the part is free of container material, but acid etching creates additional processing steps and potential surface defects
Solution Approach 1:
The patent applies self-service by selecting can materials that are inherently compatible with the powder material (matching thermal expansion coefficients and chemical compatibility). The can material becomes part of the final part without requiring removal or special treatment, making the can self-sufficient as both processing container and structural component.
Solution Approach 2:
The patent treats the can as a consumable component that is intentionally bonded to the part and remains as part of the final product. Rather than designing for can removal, the can serves its purpose during processing and then becomes an integral, permanent feature of the component, eliminating disposal and removal operations.
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
Enables the fabrication of complex, hollow metal parts with reduced defects and minimal post-processing, as the HIP can and skin expand and contract similarly, facilitating the formation of lightweight, high-strength components like aircraft parts.
Implementation Method 1
the skin component, the HIP can and the metal powder are formed from metals with the same thermal expansion coefficient ± 15% differential
Implementation Method 2
The HIP can may be welded to the skin using electron beam welding
Implementation Method 3
a vent into the hollow space to allow pressure applied during the HIP process to be communicated into the hollow space
Implementation Method 4
The powder is placed into a container, known as a can, which is shaped according to the desired component's shape. The can containing the powder is evacuated to remove any gaseous elements and then sealed and held at a high pressure and temperature. The powder particles fuse and diffusion bond into a solid mass
Implementation Method 5
The powder particles fuse and diffusion bond into a solid mass producing a component having an external shape defined by the internal shape of the can
Data Source
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AI summary
A method of manufacturing a part, the method involving providing an apparatus, the apparatus having a metal skin component; a metal HIP can and a hollow space between a portion of the HIP can and a portion of the skin component, the method further involving filling the HIP can with a metal powder;evacuating the HIP can;sealing the evacuated HIP can; and applying a HIP process to the apparatus in a HIP chamber so as to form the part.