Pulsed Laser Cladding for Abrasive Particle Embedding
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Solution Overview
Problem
Existing methods for cladding substrates with abrasive particles, such as those used in turbine components, face challenges including particle damage from laser light, the need for special coatings, and difficulty in controlling the process, leading to inhomogeneous surfaces and reduced abrasive properties.
Innovation Solution
A process involving an energy beam directed as a pulse and a stream of particles, where the energy pulse is ended or the beam is redirected before the particles enter the molten pool, preventing substantial melting or change in the particles, allowing them to be trapped in a solidified state with preserved sharp features and uniform distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a continuous energy beam is used to create a molten pool for particle embedding, then the particles can be trapped in the solidified material, but the particles undergo substantial melting and loss of sharp features
Solution Approach 1:
The patent applies periodic pulsed energy beam irradiation instead of continuous irradiation. The energy beam is delivered in discrete pulses with specific duration and intensity, allowing the molten pool to be created and particles to be embedded before the beam is interrupted. This periodic action limits the total thermal exposure time of particles, preventing substantial melting while still achieving effective embedding in the solidified matrix.
2Reliability
If the energy beam intensity is increased to ensure complete particle embedding, then particle trapping is improved, but particle damage and melting increases
Solution Approach 1:
The patent employs dynamic control of the energy beam parameters including variable pulse duration, intensity modulation, and timing synchronization with particle feed. The beam intensity and pulse width are dynamically adjusted based on process requirements, allowing optimization of embedding effectiveness while minimizing thermal damage to particles through controlled temporal and spatial energy distribution.
3Object-affected harmful factors
If special thermal insulating coatings are applied to particles before processing, then particle protection from laser damage is improved, but process complexity and manufacturing steps increase
Solution Approach 1:
The patent extracts and eliminates the requirement for special thermal insulating coatings on particles by using pulsed energy beam processing. The short duration pulses limit heat diffusion into particles, making thermal protection coatings unnecessary. This simplifies the overall process by removing the coating application step while still achieving effective particle protection through temporal control of energy input.
4Stability of the object's composition
If the energy beam pulse duration is extended to ensure thorough mixing and embedding, then particle distribution homogeneity improves, but particle melting and agglomeration increases
Solution Approach 1:
The patent applies preliminary action by creating the molten pool and establishing proper fluid dynamics before introducing particles into the energy beam path. The pool is pre-formed with appropriate temperature and flow characteristics, allowing particles to be rapidly incorporated and distributed during the pulse duration without requiring extended exposure times that would cause melting and agglomeration.
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 approach ensures that temperature-sensitive particles are not damaged, maintaining their abrasive properties and achieving a robust, uniformly abrasive surface without the need for special coatings or tightly controlled partial melting, resulting in a more efficient and controlled cladding process.
Implementation Method 1
directing an energy beam onto an area of a surface of a substrate to create a pool of molten material at the area of the surface
Implementation Method 2
allowing the pool of molten material to cool and solidify thus trapping a second portion of the particles in the solidified pool of material
Data Source
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AI summary
A process for cladding a substrate 1 is disclosed. The process comprises the steps of (i) directing an energy beam 2 onto an area 3 of a surface 4 of the substrate 1 to create a pool of molten material 5 at the area 3 of the surface 4, (ii) directing a stream 6 of particles 7 toward the pool of molten material 5 so that at least a first portion of the particles 7 enters the pool of molten material, iii allowing the pool of molten material 5 to cool and solidify thus trapping a second portion of the particles 7 in the solidified pool of material 8 to form trapped particles 71, wherein the energy beam 2 directed at the area 3 of the surface 4 is in the form of a energy pulse and the stream 6 of particles 7 is in the form of a pulse of particles 7, wherein the energy pulse is ended or the energy beam 2 is redirected or the energy beam 2 is reduced in power before the particles 7 enter the path of the energy beam 2 and before the particles 7 enter the pool of molten material 5, and wherein the ending of the energy pulse or the redirection of the energy beam 2 or the reduction in power of the energy beam 2 is embodied such that a substantial melting, fusing together or change in shape of the particles 7 by the energy beam 2 is avoided. The invention further relates to an apparatus 16 for carrying out said process. The present invention further relates also to the use of the process or apparatus 6 in cladding turbine components and to clad substrates obtainable by said process.