Optimization of selective laser melting parameters to enhance mechanical properties of titanium alloy for bone tissue engineering scaffolds

: Background In recent years, selective laser melting (SLM) technology for manufacturing titanium alloy bone tissue engineering scaffolds (BTES) has attracted much attention. Problem However, the SLM process parameters have a great influence on the mechanical properties of the scaffolds, and the optimization of SLM process parameters, such as laser power, scanning speed and layer thickness, is still needed. Design/Methodology In this paper, a full factorial design of experiments (DoE) methodology was used to set up the process parameter matrix, and the compression test was performed on the brackets by fabricating Schwarz P (Primitives) structural brackets of two different materials, namely, Ti-5Al-4.75Mo-4.75V and Ti6Al4V, and the test results of the loads, displacements, stresses, strains, compressive strengths, and Young's modulus were analyzed and finally optimized and characterized. The data were analyzed to finally optimize the process parameters and characterized. Findings The stress-strain curve of porous titanium alloy BTES showed five stages, including nonlinear deformation stage, elastic deformation stage, elastic-plastic deformation stage, strengthening stage, and failure fracture densification stage. For compressive strength, the three single factors of Laser Power, Scanning Speed, Scanning Spacing, and the interaction of Laser Power-Scanning Spacing have an effect, and the compressive strength will be increased with the increase of laser power and the decrease of scanning speed and scanning spacing. For Young's modulus, the three single factors, Laser Power, Scanning Speed, Scanning Spacing, and the interaction of Scanning Speed-Scanning Spacing, have an effect, and the Young's modulus will increase as the laser power and scanning spacing increase and the scanning speed decreases. The mechanical properties of the samples of Ti-5Al-4.75Mo-4.75V are better than those of Ti-6Al-4V both in terms of Young's modulus and compressive strength. The BTES of titanium alloys with the The titanium alloy BTES with Schwarz P (Primitives) structure has 2 failure forms, layer-by-layer compression and diagonal damage. After these two materials were compressed, the samples of Ti-5Al-4.75Mo-4.75V showed a better form of failure with cracking than Ti-6Al-4V. Impact and significant of this paper The optimization method of SLM process parameters studied in this paper, the influence law of SLM process parameters on the structural properties of TPMS, provides a theoretical basis reference for the enhancement of the titanium alloy material preparation process, and provides a practical application value for obtaining a higher mechanical properties and more effective titanium alloy BTES.