X-ray Tube Target Brazed Emission Layer Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Newer x-ray tubes face reliability and performance issues due to high peak temperatures at the target assembly, particularly at the target 'track,' when higher peak power is applied, leading to life and reliability concerns.
Innovation Solution
A method and apparatus for brazing a target track to a target substrate in an x-ray tube using a braze joint formed by interdiffusing an initial braze material between the substrate and track materials at elevated temperatures, creating a strong bond that enhances thermal performance and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If higher peak power is applied to the x-ray tube, then the x-ray generation capability is improved, but the peak temperature at the target track increases causing reliability issues
Solution Approach 1:
The patent applies composite materials by creating a multi-layer target structure consisting of a target substrate, a track layer, and a braze joint layer. The track material (e.g., tungsten or tungsten alloy) is bonded to the target substrate (e.g., copper or copper alloy) through a braze joint, forming a composite structure that combines the high melting point and x-ray generation capability of the track material with the high thermal conductivity of the substrate material, thereby managing peak temperatures while maintaining reliability
Solution Approach 2:
The patent employs parameter changes by modifying the physical and chemical properties of the materials and their interfaces. Specifically, the braze joint material is selected and processed to achieve optimal bonding strength and thermal conductivity at the interface between the track and substrate. The brazing temperature, time, and material composition are optimized to create a joint that can withstand high peak temperatures while maintaining structural integrity, thus resolving the contradiction between power handling and reliability
2Temperature
If the target rotates faster to counter high peak temperatures, then the thermal management is improved, but the reliability and performance of other components deteriorates
Solution Approach 1:
The patent changes the thermal parameters of the target assembly by optimizing the braze joint's thermal conductivity and bonding strength. This allows the system to manage peak temperatures through improved heat conduction at the track-substrate interface rather than relying solely on rotational cooling, thereby maintaining component reliability at lower rotational speeds
3Strength
If a braze joint is formed by interdiffusing initial joint material at elevated temperatures, then the bond strength between substrate and track is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent uses an intermediary braze joint material that facilitates bonding between the track and substrate. This intermediate layer enables diffusion bonding at elevated temperatures, creating a strong metallurgical bond that is superior to mechanical bonding methods. The braze material acts as a mediator that promotes atomic diffusion and bond formation, achieving high bond strength while keeping the manufacturing process manageable through controlled thermal processing
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
The braze joint improves the thermal management and reliability of the x-ray tube target, allowing for higher peak power operation without compromising the reliability of other components, by forming a strong and durable bond between the target substrate and track materials.
Implementation Method 1
elevating a temperature of the substrate, the track, and the initial joint material to disperse the initial joint material into at least one of the substrate and the track to form a final joint therebetween
Data Source
AI summary
A target for generating x-rays includes a target substrate comprising molybdenum and having a beveled surface according to a desired track angle, a track comprising tungsten and configured to generate x-rays from high-energy electrons impinging thereon, wherein the track comprises a brazing surface having an area that is less than an area of the beveled surface of the target substrate, and a braze joint attaching the brazing surface of the track to the beveled surface of the target substrate.