Magnesium Microtube Drawing for Precise Dimensions and Biodegradation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods struggle to produce thin, narrow magnesium tubes with precise dimensions and controlled biodegradation time for biodegradable medical devices like stents, due to limitations in material processing and dimensional precision, especially for tubes with diameters of 2 mm or less and lengths of 500 mm or greater.
Innovation Solution
A drawing method and apparatus that orient the hexagonal basal plane of magnesium crystals at a predetermined inclination angle, using a die and mandrel system to achieve precise diameter reduction and maintain thickness, allowing for controlled biodegradation and improved ductility without altering the material composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If magnesium material is used for biodegradable stents, then biodegradability is improved, but ductility is insufficient and breaking easily occurs during expansion
Solution Approach 1:
The patent applies parameter changes by controlling the crystal orientation parameters of magnesium. Specifically, it orients the hexagonal basal plane <0001> at a predetermined inclination angle (30-60 degrees) relative to the tube axis direction, which fundamentally changes the material's deformation behavior and enables both biodegradability and sufficient ductility for stent expansion.
2Duration of action of moving object
If magnesium material is used for biodegradable stents, then biodegradability is improved, but workability is extremely insufficient due to limited slip system
Solution Approach 1:
The patent changes the crystal orientation parameters of magnesium to overcome the limited slip system issue. By orienting the basal plane <0001> at a specific inclination angle, it activates additional slip systems that are not available in conventional randomly oriented magnesium, thereby dramatically improving workability while preserving biodegradability.
3Ease of manufacture
If conventional drawing methods are used for magnesium tubes, then manufacturing is simplified, but dimensional precision is poor and length does not satisfy 100 mm
Solution Approach 1:
The patent applies preliminary action by pre-orienting the crystal structure of magnesium before the drawing process. This preliminary crystal orientation ensures that during subsequent drawing and expansion operations, the material deforms uniformly and maintains high dimensional precision, enabling production of tubes with outer diameter ≤2mm and length ≥500mm with precision of 0.15mm or less.
4Reliability
If material composition is changed to control biodegradation time and enhance ductility, then performance is improved, but mass production efficiency is poor
Solution Approach 1:
Instead of changing material composition, the patent changes the crystal orientation parameters of pure magnesium or near-pure magnesium. This approach maintains material consistency across production batches, enabling precise control of biodegradation time through orientation control while preserving high mass production efficiency, as the same magnesium material can be used with different orientation treatments.
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 method enables the production of magnesium tubes with high precision in outer and inner diameters and thickness, enhancing biodegradability and mechanical properties, such as increased corrosion rate and balanced thickness and width reduction, suitable for biodegradable medical devices.
Implementation Method 1
when the crystals forming the round tube are viewed in a round tube axis direction of the round tube, a hexagonal basal plane (0001) is oriented at a predetermined inclination angle with respect to a circumferential direction perpendicular to a radial direction
Data Source
AI summary
Provided is a thin, narrow tube for use in a biodegradable medical device formed from a round tube made of a magnesium material as the base material, in which a desired outer diameter and an inner diameter are provided with good precision over the entire region in a longitudinal direction and a circumferential direction, and the length of biodegradation time can be controlled without changing a material composition. The thin, narrow tube is a thin, narrow tube of a biodegradable medical device, in which the thin, narrow tube is a round tube made of crystals containing magnesium (Mg) having a hexagonal crystal structure, and when the crystals forming the round tube are viewed in a round tube axis direction of the round tube, a hexagonal basal plane (0001) is oriented at a predetermined inclination angle with respect to a circumferential direction perpendicular to a radial direction (a direction from an inner surface to an outer surface) of the round tube.