A novel method for the fabrication of tubular WE43 magnesium scaffold based on laser micro-spot welding

Abstract

Biodegradable materials such as WE43 magnesium are of great interest for bone tissue engineering applications. This research paper presents a novel manufacturing methodology (i.e., Joining Stacking based Laser Micro-Spot Welding (JS-LMSW)) for produce tubular WE43 Magnesium scaffolds. The proposed methodology consists of laser-cut tailored geometries joined and stacked using laser micro-spot welding to form a porous structure (scaffold). The relationship between microstructure and mechanical properties of the manufactured WE43 magnesium scaffolds is summarized in this paper. Additionally, the manufactured scaffolds were dimensionally and morphologically characterized, and the obtained results are close to the designed values (relative errors of ∼ 1.04%, 0.93%, 0.83%, and 1.53% for length, width, height, and interconnected porosity, respectively). Compressive testing was conducted on the scaffolds for axial and transversal loading conditions and, micro-hardness was evaluated in the micro spot welds. The obtained results indicated that the developed WE43 magnesium scaffold features bone-like mechanical properties. The elastic modulus range of cancellous bone is between 0.01 and 0.90 GPa compared to WE43 magnesium scaffold́s elastic modulus between 0.07 and 0.41 GPa for transversal and axial conditions, respectively. Hardness results showed values between 74 HV and 80 HV in the fusion zone and heat-affected zone, respectively. This novel methodology opens a new path for the construction of complex geometries such as scaffolds.

Keywords

• WE43 magnesium
• Laser micro spot welding
• Tube stacking
• Stress shielding
• Bone tissue engineering
• Biodegradable scaffold