3D printing of Aluminium alloys: Additive Manufacturing of Aluminium alloys using selective laser melting

High-speed 3D shape measurement with structured light methods: A review

A critical review of powder-based additive manufacturing of ferrous alloys: Process parameters, microstructure and mechanical properties

Three-dimensional (3D) printing enables the production of anatomically matched and patient-specific devices and constructs with high tunability and complexity. It also allows on-demand fabrication with high productivity in a cost-effective manner. As a result, 3D printing has become a leading manufacturing technique in healthcare and medicine for a wide range of applications including dentistry, tissue engineering and regenerative medicine, engineered tissue models, medical devices, anatomical models and drug formulation. Today, 3D printing is widely adopted by the healthcare industry and academia. It provides commercially available medical products and a platform for emerging research areas including tissue and organ printing. In this review, our goal is to discuss the current and emerging applications of 3D printing in medicine. A brief summary on additive manufacturing technologies and available printable materials is also given. The technological and regulatory barriers that are slowing down the full implementation of 3D printing in the medical field are also discussed.

https://iopscience.iop.org/article/10.1088/1758-5090/aa7279/pdf

Current and emerging applications of 3D printing in medicine.

Effects of defects on mechanical properties in metal additive manufacturing: A review focusing on X-ray tomography insights

Effect of matte coating on 3D optical measurement accuracy

Purpose – The purpose of this paper is to describe a manufacturing methodology for a wrist orthosis. The case study aims to offer new approaches in the area of human orthoses. Design/methodology/approach – The article describes the utilization of rapid prototyping (RP), passive stereo photogrammetry and software tools for the orthosis design process. This study shows the key points of the design and manufacturing methodology. The approach uses specific technologies, such as 3D digitizing, reverse engineering and polygonal-surface software, FDM RP and 3D printing. Findings – The results show that the used technologies reflect the patient's requirements and also they could be an alternative solution to the standard method of orthosis design. Research limitations/implications – The methodology provides a good position for further development issues. Practical implications – The methodology could be usable for clinical practice and allows the manufacturing of the perfect orthosis of the upper limb. The usage ...

Pilot study of the wrist orthosis design process

This paper deals with various selective laser melting (SLM) processing strategies for aluminum 2618 powder in order to get material densities and properties close to conventionally-produced, high-strength 2618 alloy. To evaluate the influence of laser scanning strategies on the resulting porosity and mechanical properties a row of experiments was done. Three types of samples were used: single-track welds, bulk samples and samples for tensile testing. Single-track welds were used to find the appropriate processing parameters for achieving continuous and well-shaped welds. The bulk samples were built with different scanning strategies with the aim of reaching a low relative porosity of the material. The combination of the chessboard strategy with a 2 × 2 mm field size fabricated with an out-in spiral order was found to eliminate a major lack of fusion defects. However, small cracks in the material structure were found over the complete range of tested parameters. The decisive criteria was the elimination of small cracks that drastically reduced mechanical properties. Reduction of the thermal gradient using support structures or fabrication under elevated temperatures shows a promising approach to eliminating the cracks. Mechanical properties of samples produced by SLM were compared with the properties of extruded material. The results showed that the SLM-processed 2618 alloy could only reach one half of the yield strength and tensile strength of extruded material. This is mainly due to the occurrence of small cracks in the structure of the built material.

Influence of Scanning Strategies on Processing of Aluminum Alloy EN AW 2618 Using Selective Laser Melting

The aim of this study is to observe the effect of process parameters on residual stresses and relative density of Ti6Al4V samples produced by Selective Laser Melting. The investigated parameters were hatch laser power, hatch laser velocity, border laser velocity, high-temperature preheating and time delay. Residual stresses were evaluated by the bridge curvature method and relative density by the optical method. The effect of the observed process parameters was estimated by the design of experiment and surface response methods. It was found that for an effective residual stress reduction, the high preheating temperature was the most significant parameter. High preheating temperature also increased the relative density but caused changes in the chemical composition of Ti6Al4V unmelted powder. Chemical analysis proved that after one build job with high preheating temperature, oxygen and hydrogen content exceeded the ASTM B348 limits for Grade 5 titanium.

https://www.mdpi.com/1996-1944/12/6/930/pdf

David Paloušek

Papers

Effect of matte coating on 3D optical measurement accuracy

Pilot study of the wrist orthosis design process

Influence of Scanning Strategies on Processing of Aluminum Alloy EN AW 2618 Using Selective Laser Melting

Effect of Process Parameters and High-Temperature Preheating on Residual Stress and Relative Density of Ti6Al4V Processed by Selective Laser Melting

Finite element analysis for the evaluation of the structural behaviour, of a prosthesis for trans-tibial amputees.