Titanium-Magnesium Implant Structure for Stress Shielding Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current medical implant alloys, such as titanium and magnesium alloys, face challenges such as 'stress shielding' due to mismatched Young's modulus with natural bone, poor bone-promoting properties, and excessive degradation, leading to inefficiencies in bone repair and replacement, especially in pelvic bone and hip joint applications.
Innovation Solution
A titanium-magnesium interpenetrating phase composite structure is prepared using additive manufacturing and pressureless infiltration or hot isostatic pressing, creating a porous skeleton with a Young's modulus adjustable within the range of 10-20 GPa and compressive strength exceeding 180 MPA, combined with a hydroxyapatite coating to enhance biocompatibility and bone integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If titanium alloy is used for medical implant, then strength is improved, but bone-promoting property deteriorates and bone-forming period is prolonged
Solution Approach 1:
The patent creates a composite structure by filling magnesium alloy powder into the porous titanium alloy skeleton, combining the high strength of titanium with the bone-promoting properties of magnesium. The titanium alloy provides structural support while the magnesium alloy fills the pores to enhance osteogenesis, resolving the contradiction between strength and bone-promoting property.
Solution Approach 2:
The patent utilizes a porous titanium alloy skeleton with controlled porosity (30-70%) created through additive manufacturing. This porous structure allows magnesium alloy powder to be filled inside, increasing the surface area for bone attachment and facilitating bone ingrowth, thereby improving bone-promoting property while maintaining overall structural strength.
2Reliability
If magnesium alloy is used for medical implant, then bone-promoting activity is improved, but degradation resistance deteriorates
Solution Approach 1:
The patent combines magnesium alloy powder with titanium alloy skeleton to create a composite structure where the titanium provides long-term structural support and corrosion resistance, while the magnesium provides bone-promoting activity. The titanium matrix protects the magnesium from rapid degradation while still allowing it to maintain bone health.
Solution Approach 2:
The patent applies different materials to different locations within the implant structure - the titanium alloy forms the external skeleton that provides structural integrity and degradation resistance, while the magnesium alloy is localized within the porous pores to provide bone-promoting activity at the bone-implant interface, where it is most needed.
3Manufacturing precision
If traditional processing techniques are used for implant preparation, then manufacturing precision is improved, but production cost deteriorates
Solution Approach 1:
The patent employs additive manufacturing technology that allows for digital design and direct fabrication of complex porous structures with precise control over porosity (30-70%) and pore distribution. This digital approach enables customization without requiring expensive custom molds or extensive material removal, reducing production costs while maintaining high manufacturing precision.
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 composite structure effectively addresses 'stress shielding' by matching the mechanical properties of natural bone, enhances bone formation through magnesium's bone-promoting activity, and slows down magnesium degradation with the hydroxyapatite coating, thereby improving the efficacy and durability of pelvic bone and hip joint implants.
Implementation Method 1
preparing, based on a selective laser melting technique or a laser powder bed fusion technique, titanium alloy powder into a porous skeleton
Implementation Method 2
filling magnesium after being melted into pores of the porous skeleton
Implementation Method 3
filling magnesium after being melted into pores of the porous skeleton by means of magnesium pressureless infiltration or hot isostatic pressing
Implementation Method 4
covering a surface of the titanium-magnesium interpenetrating phase composite structure with a hydroxyapatite coating
Data Source
AI summary
Disclosed is a method for preparing a heterogeneous metal composite structure for medical implantation, including the steps of: step 1, preparing titanium alloy powder into a porous skeleton according to different printing strategies; step 2, filling magnesium after being melted into pores of the porous skeleton; and step 3, cooling a titanium-magnesium interpenetrating phase composite structure prepared in step 2 to room temperature, and covering a surface of the titanium-magnesium interpenetrating phase composite structure with a hydroxyapatite coating. In the present disclosure, a porous lattice dot-array structure of titanium alloy is used as a skeleton, and the skeleton pore is filled by pressureless infiltration of magnesium or hot isostatic pressure.