Novel high-strength low-modulus 3D printing titanium alloy porous hard bone scaffold

Abstract

The utility model discloses a novel high-strength low-modulus 3D printing titanium alloy porous hard bone scaffold which is characterized by comprising a plurality of lattice units, the outer contour of each lattice unit is of a cube hollow structure, the top face, the bottom face and the four side faces of each cube hollow structure are each composed of two supporting rods which are arranged in a perpendicularly-crossed mode, and the supporting rods are arranged in a staggered mode. The supporting rods on every two adjacent faces are connected with each other, and the cross points of the supporting rods on the four side faces are sequentially connected through axial stress rods. And a plurality of structural unit arrays form the porous hard bone scaffold. According to the porous hard bone scaffold structure, a lattice configuration with ultra-low weight and good mechanical property can be obtained, and the mechanical property of the structure is effectively improved by axially adding a group of stress rods, so that the compressive strength is greatly improved on the premise that the elastic modulus is not increased; and the supporting column is prevented from being fractured in a fracture mode before a stress rod is added, and cracks are prevented from expanding along 45 degrees.

Description

Technical Field

[0001] The utility model relates to the technical field of porous titanium alloys, and in particular to a novel high-strength, low-modulus 3D-printed titanium alloy porous hard bone scaffold. Background Art

[0002] In addition to attractive properties such as high strength and light weight, titanium alloys are widely used as biomaterials due to their relatively low elastic modulus, good biocompatibility and corrosion resistance. However, compared to human bones, the elastic modulus of titanium alloys is still dozens of times that of human bones, which can form a stress shielding effect and cause the graft to fall off. Porous titanium alloys are a promising alternative orthopedic implant material because they can be produced with customized stiffness and improve mechanical compatibility with bone tissue. The interconnected pore structure also allows bone to grow inward, providing strong bone interlocking. Currently, various technologies produce titanium alloy scaffolds.

[0003] Among them, additive manufacturing (AM) has gained a lot of attention in the past few years because it has great advantages: the scaffold can be easily customized according to other structural requirements, and the pore size, porosity, unit structure and interconnectivity can be controlled directly from the CAD model.

[0004] Under such conditions, it becomes possible to purposefully regulate the unit structure to obtain ideal mechanical properties. This design pattern has also become an important development direction for biomedical titanium alloys. Utility Model Content

[0005] In view of this, the purpose of the present invention is to provide a new type of high-strength, low-modulus 3D printed titanium alloy porous hard bone scaffold to solve one or more of the above-mentioned prior art problems.

[0006] To achieve the above-mentioned purpose, the utility model provides a new type of high-strength, low-modulus 3D-printed titanium alloy porous hard bone scaffold, a new type of high-strength, low-modulus 3D-printed titanium alloy porous hard bone scaffold, characterized in that it includes a plurality of lattice units, the outer contour of the lattice unit is a cubic hollow structure, the top surface, bottom surface and four side surfaces of the cubic hollow structure are respectively composed of two vertically cross-arranged support rods, the support rods of each two adjacent surfaces are connected to each other, and the intersection points of the support rods on the four side surfaces are connected in sequence through axial force rods; a plurality of the lattice unit arrays form a porous hard bone scaffold.

[0007] In some embodiments, the length of the support rod is 2.5 mm, and the diameter of the support rod is 0.227 mm.

[0008] In some embodiments, the length of the stress-bearing rod is 2.5 mm, and the diameter of the stress-bearing rod is 0.227 mm.

[0009] In some embodiments, the support rod and the stress-bearing rod are cylindrical structures formed by pressing Ti-6Al-4V powder with a particle size of 45-106 μm.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] The utility model provides a novel high-strength, low-modulus 3D-printed titanium alloy porous hard bone scaffold structure, which can obtain a lattice configuration with both ultra-low weight and good mechanical properties, and effectively improves the mechanical properties of the structure by axially adding a group of stress-bearing rods, so that the compressive strength is greatly improved without increasing the elastic modulus, preventing the fracture mode before adding the stress-bearing rods from showing a pillar fracture and the crack extending along 45°. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of a lattice unit structure of a novel high-strength, low-modulus 3D-printed titanium alloy porous hard bone scaffold in one embodiment of the utility model;

[0013] Figure 2 This is a schematic diagram of the lattice unit structure of a novel high-strength, low-modulus 3D-printed titanium alloy porous hard bone scaffold in a pair of ratios of the utility model;

[0014] Figure 3 This is a schematic diagram of the structure of a new type of high-strength, low-modulus 3D printed titanium alloy porous bone scaffold in a pair of ratios of the utility model;

[0015] Figure 4 This is an optical metallographic image of a lattice unit of a novel high-strength, low-modulus 3D-printed titanium alloy porous hard bone scaffold in one embodiment of the utility model;

[0016] Figure 5 This is an optical metallographic image of a lattice unit of a novel high-strength, low-modulus 3D-printed titanium alloy porous hard bone scaffold in a pair of ratios of the utility model;

[0017] Figure 6 The stress-strain curves of the lattice unit structure of the embodiment and the lattice unit structure of the comparative example obtained after compression test;

[0018] Figure 7 It is a data comparison chart of the compressive strength, elastic modulus, and the ratio of the lattice unit structure of the embodiment and the lattice unit structure of the comparative example. DETAILED DESCRIPTION

[0019] The utility model is described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Example 1

[0021] like Figure 1As shown:

[0022] A novel high-strength, low-modulus 3D-printed titanium alloy porous bone scaffold, comprising a plurality of lattice units, the outer contour of the lattice unit is a cubic hollow structure, the top surface, bottom surface and four side surfaces of the cubic hollow structure are respectively composed of two vertically cross-arranged support rods 1, the support rods 1 of each two adjacent surfaces are connected to each other, and the intersection points of the support rods 1 on the four side surfaces are connected in sequence through axial force-bearing rods 2; a plurality of the lattice unit arrays form a porous bone scaffold, the length of the support rod is 2.5 mm, the diameter of the support rod is 0.227 mm, the length of the force-bearing rod is 2.5 mm, the diameter of the force-bearing rod is 0.227 mm, the support rod and the force-bearing rod are cylindrical structures pressed from Ti-6Al-4V powder with a particle size of 45-106 μm, and the size of the porous bone scaffold is 10x10x15 mm, such as Figure 3 As shown, it is recorded as AFCC-X structure.

[0023] The porous hard bone scaffold is prepared by an EBM printer. The equipment uses the high-density energy generated at the focal point after deflection and focusing of a high-energy electron beam to generate high temperature in a local tiny area of ​​the scanned metal powder layer, causing the metal particles to melt. Continuous scanning of the electron beam will cause tiny metal molten pools to fuse and solidify with each other, connecting to form linear and surface metal layers.

[0024] Comparative Example 1

[0025] like Figure 2 As shown, the difference from Example 1 is that there is no axial force-bearing rod in the lattice unit structure of Comparative Example 1, which is recorded as an AFCC structure.

[0026] from Figure 4 and 5 From the optical metallographic images of the AFCC structure and the AFCC-X structure, it can be seen that after the crossbar is added, the structure of the AFCC-X structure is affected by the heat-affected zone during printing, and the structure is finer in morphology, so the structure strength is higher.

[0027] from Figure 6 From the stress-strain curves obtained after the compression test of the AFCC structure and the AFCC-X structure, it can be seen that the elastic modulus of the AFCC-X structure did not change significantly compared with the AFCC prototype structure, but from the peak of the curve, it can be seen that the compressive strength of the ADCC-X structure increased by about 20MPa. It can be considered that the AFCC-X structure has greatly improved the compressive strength without increasing the elastic modulus, and optimized the mechanical properties of the original AFCC structure.

[0028] from Figure 7Comparison of the compressive strength, elastic modulus, and ratio of the AFCC structure and the AFCC-X structure shows that the compressive strength of the AFCC-X structure is greatly improved, while the elastic modulus has a small increase, and the ratio of compressive strength to elastic modulus has been significantly improved.

[0029] Therefore, a new type of high-strength, low-modulus 3D printed titanium alloy porous hard bone scaffold structure in an embodiment of the utility model can obtain a lattice configuration with both ultra-low weight and good mechanical properties, and by adding a group of stress-bearing rods axially, the mechanical properties of the structure are effectively improved, so that the compressive strength is greatly improved without increasing the elastic modulus, and the fracture mode before the addition of the stress-bearing rods is prevented from showing a pillar fracture and the crack extending along 45°.

[0030] Finally, it should be noted that: technicians in this industry should understand that the utility model is not limited to the above-mentioned implementation cases. The above-mentioned embodiments and descriptions only illustrate the principles of the utility model. Without departing from the spirit and scope of the utility model, the utility model will have various changes and improvements, and these changes and improvements must fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A new type of high-strength low-modulus 3D printed titanium alloy porous bone scaffold, characterized in that: It comprises a plurality of lattice units, the outer contour of which is a hollow cube structure. The top surface, bottom surface and four side surfaces of the hollow cube structure are respectively formed by two vertically cross-arranged support rods, the support rods of every two adjacent surfaces are connected to each other, and the intersection points of the support rods on the four side surfaces are connected in sequence through axial force-bearing rods; an array of the plurality of lattice units forms a porous hard bone scaffold.

2. A novel high-strength, low-modulus 3D printed titanium alloy porous bone scaffold as claimed in claim 1, characterized in that: The length of the support rod is 2.5 mm, and the diameter of the support rod is 0.227 mm.

3. A novel high-strength, low-modulus 3D printed titanium alloy porous bone scaffold as claimed in claim 1, characterized in that: The length of the stress-bearing rod is 2.5 mm, and the diameter of the stress-bearing rod is 0.227 mm.

4. A novel high-strength, low-modulus 3D printed titanium alloy porous bone scaffold as claimed in claim 1, characterized in that: The support rod and the stress-bearing rod are cylindrical structures formed by pressing Ti-6Al-4V powder with a particle size of 45-106 μm.

5. A novel high-strength, low-modulus 3D printed titanium alloy porous bone scaffold as claimed in claim 1, characterized in that: The size of the porous bone scaffold is 10x10x15mm.

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