scholarly journals A Review on Design and Mechanical Properties of Additively Manufactured NiTi Implants for Orthopedic Applications

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Yintao Zhang ◽  
Shokouh Attarilar ◽  
Liqiang Wang ◽  
Weijie Lu ◽  
Junlin Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Porous Structure ◽  
Niti Alloy ◽  
Fatigue Behavior ◽  
Processing Parameters ◽  
Structure Design ◽  
Design Parameters ◽  
Powder Preparation ◽  
Wide Range ◽  
Manufacturing Technologies

NiTi alloy has a wide range of applications as a biomaterial due to its high ductility, low corrosion rate, and favorable biocompatibility. Although Young’s modulus of NiTi is relatively low, it still needs to be reduced; one of the promising ways is by introducing porous structure. Traditional manufacturing processes, such as casting, can hardly produce complex porous structures. Additive manufacturing (AM) is one of the most advanced manufacturing technologies that can solve impurity issues, and selective laser melting (SLM) is one of the well-known methods. This paper reviews the developments of AMNiTi with a particular focus on SLM-NiTi utilization in biomedical applications. Correspondingly, this paper aims to describe the three key factors, including powder preparation, processing parameters, and gas atmosphere during the overall process of porous NiTi. The porous structure design is of vital importance, so the unit cell and pore parameters are discussed. The mechanical properties of SLM-NiTi, such as hardness, compressive strength, tensile strength, fatigue behavior, and damping properties and their relationship with design parameters are summarized. In the end, it points out the current challenges. Considering the increasing application of NiTi implants, this review paper may open new frontiers for advanced and modern designs.

Computational Study of a Target Fluidic Flowmeter

2010 ◽  
Author(s):  
Andrzej F. Nowakowski ◽  
Franck C. G. A. Nicolleau ◽  
S. M. Muztaba Salim
Keyword(s):  
Reynolds Number ◽  
Computational Study ◽  
Numerical Technique ◽  
Three Dimensional ◽  
Boundary Layer Separation ◽  
Structure Design ◽  
Design Parameters ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Wide Range

The computational studies on the flow structure, design and performance of a target fluidic flowmeter have been carried out. The computational challenge was to find a universal approach to study a wide range of flow regimes. To this end the Detached Eddy Simulation (DES) approach for unsteady flows was applied. The numerical technique enabled to accurately reproduced three dimensional flow structures in a target fluidic flowmeter. The signal analysis of the obtained results was conducted for a range of Reynolds numbers from laminar case up to 4000. The results show that a number of factors such as meter geometry and aspect ratio can influence the performance of the flow meter significantly. A minimum Reynolds number constraint for the measurements to be accurate was evaluated for various design parameters. The significance of using knife edges which influence boundary layer separation was also established. The experimental data, which were obtained for a prototype of flowmeter setup were used to validate numerical tools in the important area of low Reynolds number flows.

scholarly journals An overview of additive manufacturing technologies for musical wind instruments

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Ajith Damodaran ◽  
M. Sugavaneswaran ◽  
Larry Lessard
Keyword(s):  
Additive Manufacturing ◽  
Processing Parameters ◽  
Design Parameters ◽  
Wind Instruments ◽  
Systematic Review Methodology ◽  
Professional Musicians ◽  
Ancient Music ◽  
Materials Used ◽  
Technical Features ◽  
Manufacturing Technologies

AbstractThis paper aimed to provide a foundation database for understanding the important applications of the different additive manufacturing (AM) technologies for musical wind instruments. A systematic review methodology was adopted in this study. The different AM techniques, materials used, the technical features, and processing parameters uniquely related to wind instruments were discussed. Selected heterogeneous applications demonstrate how AM techniques are being exploited in the innovation, improvement in aesthetics of the existing wind instruments, understanding the ancient music, and personalization with its capability to tune specific instrument design parameters for professional musicians.

Analysis of the process influences on injection molded thermosets filled with hollow glass bubbles

2018 ◽  
Vol 38 (7) ◽  
pp. 695-701
Author(s):  
Christian Hopmann ◽  
Matthias Theunissen ◽  
Stefan Haase
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Processing Parameters ◽  
Injection Molding Process ◽  
Filler Materials ◽  
Molding Process ◽  
Molding Compound ◽  
Hollow Glass ◽  
Molding Compounds ◽  
Wide Range

Abstract Thermoset molding compounds have a wide range of beneficial properties such as easy handling, high temperature, chemical resistance, low shrinkage as well as low electrical conductivity. However, these properties come at the cost of a higher density than technical thermoplastic materials and thus the potential for lightweight applications is reduced. Due to the low viscosity of the resin within thermoset molding compounds a wide variety of filler materials can be used. The addition of low density hollow glass bubbles as a filler material in thermoset molding compounds offers the opportunity to decrease the density of the molding compound. At the same time the stiffness of the micro glass bubbles is expected to increase the stiffness of the material. In the present study, a thermoset molding compound was filled with different quantities of hollow glass bubbles and the effects of the filler content as well as the processing parameters were investigated regarding their effect on the weight and mechanical properties of the parts. Based on the results, significant weight reductions up to 5% were achieved. Furthermore, a significant impact of the process parameters on weight reductions was found. The results indicate that higher shearing reduces the weight. This can also contribute to damaging of the glass bubbles during the injection molding process. Similar results were found regarding the effect of process parameters on the mechanical properties.

Optimization of SLM productivity by aligning 17-4PH material properties on part requirements

2014 ◽  
Vol 20 (6) ◽  
pp. 444-448 ◽  
Author(s):  
A. B. Spierings ◽  
M. Schoepf ◽  
R. Kiesel ◽  
K. Wegener
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Processing Parameters ◽  
Powder Layer ◽  
Clear Correlation ◽  
Porosity Level ◽  
Content Type ◽  
Wide Range ◽  
Material Porosity ◽  
Process Productivity

Purpose – The purpose of this study is the development of a global SLM-manufacturing optimization strategy taking into account material porosity and SLM process productivity. Selective laser melting (SLM) is a master forming process generating not only a near net shape geometry, but also the material with its properties. Research focuses primarily on optimal processing parameters for maximised material properties. However, the process allows also designing the material structure by internal porosity, affecting global material properties and the process productivity. Design/methodology/approach – The study investigates the influence of the main SLM process parameters on material porosity and consequently on the static mechanical properties of hardened SS17-4PH material. Furthermore, a model for the SLM scanning productivity is developed based on the SLM processing parameters. Findings – The results show a clear correlation between porosity level and mechanical properties. Thereby, the mechanical strength and material modulus can be varied in a wide range. The degree of internal material porosity can be correlated to the energy input defined by a set of SLM processing parameters, such as Laser power, powder layer thickness and scan speed, allowing pre-definition of a specific degree of porosity. Originality/value – Aligning of the SLM processing parameters to the technical material requirements of the parts to be produced, e.g. maximal stresses in service, required E-modulus or lightweight aspects, enlarges the general design space significantly. In combination with the presented model for the scanning productivity, it is further possible to optimize the SLM build rate.

scholarly journals A study of tensile and bending properties of 3D-printed biocompatible materials used in dental appliances

2022 ◽  
Author(s):  
Marcos García Reyes ◽  
Alex Bataller Torras ◽  
Juan A. Cabrera Carrillo ◽  
Juan M. Velasco García ◽  
Juan J. Castillo Aguilar
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Biocompatible Materials ◽  
Rupture Stress ◽  
Bending Tests ◽  
Wide Range ◽  
3D Printers ◽  
Materials Used ◽  
Manufacturing Technologies ◽  
Printing Direction

AbstractIn the last years, a large number of new biocompatible materials for 3D printers have emerged. Due to their recent appearance and rapid growth, there is little information about their mechanical properties. The design and manufacturing of oral appliances made with 3D printing technologies require knowledge of the mechanical properties of the biocompatible material used to achieve optimal performance for each application. This paper focuses on analysing the mechanical behaviour of a wide range of biocompatible materials using different additive manufacturing technologies. To this end, tensile and bending tests on different types of recent biocompatible materials used with 3D printers were conducted to evaluate the influence of the material, 3D printing technology, and printing orientation on the fragile/ductile behaviour of the manufactured devices. A test bench was used to perform tensile tests according to ASTM D638 and bending tests according to ISO 178. The specimens were manufactured with nine different materials and five manufacturing technologies. Furthermore, specimens were created with different printing technologies, biocompatible materials, and printing orientations. The maximum allowable stress, rupture stress, flexural modulus, and deformation in each of the tested specimens were recorded. Results suggest that specimens manufactured with Stereolithography (SLA) and milling (polymethyl methacrylate PMMA) achieved high maximum allowable and rupture stress values. It was also observed that Polyjet printing and Selective Laser Sintering technologies led to load–displacement curves with low maximum stress and high deformation values. Specimens manufactured with Digital Light Processing technology showed intermediate and homogeneous performance. Finally, it was observed that the printing direction significantly influences the mechanical properties of the manufactured specimens in some cases.

Determining Undeformed Chip Thickness Models in Milling and its Verification during Wood Processing

2017 ◽  
Vol 265 ◽  
pp. 598-605 ◽  
Author(s):  
A.A. Fomin
Keyword(s):  
Chip Thickness ◽  
Processing Parameters ◽  
Energy Performance ◽  
Milling Process ◽  
Design Parameters ◽  
Chip Area ◽  
Undeformed Chip Thickness ◽  
Wood Processing ◽  
Wide Range ◽  
Cutter Design

This paper presents a mathematical model of the maximum thickness and the chip area for the processes of cylindrical and profile milling of various materials, including wood. The analytical dependences connecting the geometry of the shear layer with the elements of the milling mode and cutter design parameters are determined. Also, a model of the volume of material removed from the surface of the workpiece during the milling profile is presented. The comparative calculations of the previously known models and the models developed by the author were done. It was found that the models of the geometric parameters of cutting layer presented in the article are adequate and can be used to calculate the energy performance of the wood milling process with cylindrical and shaping cutters. These models are suitable for use in the calculations of the processing parameters for a wide range of material: metals, wood, plastic, glass and others.

scholarly journals Substantiation of foamy structure formation in a gluten-free biscuit

10.5219/1399 ◽  
2020 ◽  
Vol 14 ◽  
pp. 1008-1019
Author(s):  
Igor Stadnyk ◽  
Olena Kolomiiets ◽  
Oksana Dziana
Keyword(s):  
Porous Structure ◽  
Wheat Flour ◽  
Rotation Frequency ◽  
Comparative Characteristic ◽  
Design Parameters ◽  
Gluten Free ◽  
Corn Flour ◽  
Frontal Surface ◽  
Organoleptic Characteristics ◽  
Wide Range

A promising way to create gluten-free foods based on purposeful use of ingredients with a wide range of technological properties is analyzed. Steps to regulate the structural and mechanical properties of gluten-free dough have been determined. These steps allow to improve the structural-mechanical and organoleptic characteristics of the biscuit semi-finished product, to adjust the nutritional value. To determine the technological effect, we considered the connection between the recipe components and the properties of the dough when forming a foamy structure of gluten-free cupcake products. The influence of the design parameters of the mixer (independent factors xi) on the foaming process (Q) has been determined, that is, determining the productivity magnitude from the changes of three main factors: from the attack angle of the frontal surface of the plate working body α, the distance between the plates (step) t and the rotation frequency of working body n. The stability of the foam formed and the rate of its settling and the role of the liquid phase of the dough during short storage before baking were investigated. The comparative characteristics of the microstructure of wheat flour (WF) and extruded corn flour (ECF) in the ratios are presented: a) WF – 100 wt.%; b) WF: ECF – 80:20 wt.%; c) ECF – 100 wt.%. In the tested mixtures, the moisture-holding capacity increases for the sample containing 20% by weight of extruded corn flour two and a half times, and three times for the sample with extruded flour to 100% by weight. With an increasing proportion of extruded corn flour in the flour mixture, the dough density increases and the optimum value is in the range of 0.444 – 0.446 kg.m-3. The comparative characteristic of the microstructure of the samples is given, which has the appearance of foam with the existing and even distribution of air bubbles which later form the porous structure of the biscuit of the semi-finished product. Thus, the size of the formed bubbles of air with the content of wheat flour and starch have a large difference in diameters, in the sample of biscuit dough using ECF 100 wt.% – almost the same size, and between the channels are formed that promote the equalization of air pressure in the middle of the foam system of biscuit dough. It was found that the use of 20 wt.% and 100 wt.% of corn extruded flour contributes to the formation of a fine porous structure of biscuit dough.

Effect of Processing Parameters on Mechanical Properties of 3D Printed Samples

2018 ◽  
Vol 919 ◽  
pp. 230-235 ◽  
Author(s):  
Jaroslav Maloch ◽  
Eva Hnátková ◽  
Milan Žaludek ◽  
Petr Krátký
Keyword(s):  
Mechanical Properties ◽  
Low Cost ◽  
Flexural Modulus ◽  
Acrylonitrile Butadiene Styrene ◽  
Processing Parameters ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
3D Printed ◽  
Manufacturing Technologies ◽  
Functional Components

3D printing technology enables the production of functional components in small quantities which can be used as end-use parts. The mechanical properties of the final product define its quality and determine its success or failure in a given application. One at the various additive manufacturing technologies - Fused Deposition Modelling is very often used due to its relatively low cost and the availability of 3D printers and thermoplastic materials. During the process, there are many factors that can affect the mechanical properties of the final product. The temperature of the extrusion nozzle and the layer thickness are two of the basic process parameters. The objective of this work is to investigate the effect of these two processing parameters on the final mechanical properties of the 3D printed samples from acrylonitrile butadiene styrene. Mechanical testing includes the tensile and flexural strength, as well as tensile and flexural modulus.

Tailorable Thermal Expansion of Lightweight and Robust Dual-Constituent Triangular Lattice Material

2017 ◽  
Vol 84 (10) ◽  
Author(s):  
Kai Wei ◽  
Yong Peng ◽  
Weibin Wen ◽  
Yongmao Pei ◽  
Daining Fang
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Triangular Lattice ◽  
Coefficient Of Thermal Expansion ◽  
Bulk Material ◽  
Structure Design ◽  
Thermally Induced ◽  
Precise Control ◽  
Wide Range ◽  
Lattice Material

Current studies on tailoring the coefficient of thermal expansion (CTE) of materials focused on either exploring the composition of the bulk material or the design of composites which strongly depend on a few negative CTE materials or fibers. In this work, an approach to achieve a wide range of tailorable CTEs through a dual-constituent triangular lattice material is studied. Theoretical analyses explicitly reveal that through rational arrangement of commonly available positive CTE constituents, tailorable CTEs, including negative, zero, and large positive CTEs can be easily achieved. We experimentally demonstrate this approach through CTE measurements of the specimens, which were exclusively fabricated from common alloys. The triangular lattice material fabricated from positive CTE alloys is shown to yield large positive (41.6 ppm/°C), near-zero (1.9 ppm/°C), and negative (−32.9 ppm/°C) CTEs. An analysis of the collapse strength and stiffness ensures the robust mechanical properties. Moreover, hierarchal triangular lattice material is proposed, and with certain constituents, wide range of tailorable CTEs can be easily obtained through the rationally hierarchal structure design. The triangular lattice material presented here integrates tailorable CTEs, lightweight characteristic, and robust mechanical properties, and is very promising for engineering applications where precise control of thermally induced expansion is in urgently needed.

scholarly journals 3466 Innovative 3D Printed Intravaginal Rings: Developing AnelleO PRO, the First Intravaginal Ring for Infertility

2019 ◽  
Vol 3 (s1) ◽  
pp. 58-58
Author(s):  
Rima Janusziewicz ◽  
Janus S. Rahima Benhabbour
Keyword(s):  
Mechanical Properties ◽  
In Vitro Release ◽  
Design Parameters ◽  
Vaginal Fluid ◽  
Radial Compression ◽  
Target Drug ◽  
Intravaginal Rings ◽  
Wide Range ◽  
3D Printed ◽  
Model Drug

OBJECTIVES/SPECIFIC AIMS: The study aims to develop and test a biocompatible 3D-printed IVRs for the mechanical and release properties of a model drug, β-estradiol, then translate these methods to the target drug, progesterone. The goals include demonstrating decoupling of mechanical and release properties of the rings, release profiles driven by geometry and efficacy in sheep animal models to evaluate device safety. METHODS/STUDY POPULATION: A novel 3D-printing platform, continuous liquid interface production (CLIP), pioneered by Carbon, enables the fabrication of complex designs on a timescale that is amenable to manufacturing. The process utilizes computational-aided design (CAD), specifying shape and geometry, which is recreated via a photopolymerization process. IVRs are fabricated with CLIP using a biocompatible resin at a rate of approximately 15 min. per ring. Rings were fabricated and assessed for the release of a model drug, β-estradiol. The process was then translated to the target drug, progesterone. Rings were evaluated for radial compression and in vitro release in simulated vaginal fluid (SVF). RESULTS/ANTICIPATED RESULTS: Intravaginal rings (IVRs) were designed and fabricated to be geometrically complex in an effort to control release. Ring geometry and subsequent pore size was achieved through the use of unit cells. Several design parameters were explored including unit cell type, size, and band presence in two resins of differing mechanical properties. Through design, a wide range of radial compressive properties were achieved which spanned values covered by commercially available rings. The release of β-estradiol in SVF was found to span 57 – 115 days and resulted in near or complete release of the total loaded drug. Changing the internal geometric design of the ring was found to have minimal influence on the compression properties, thus the mechanical and release characteristics of the rings were largely decoupled. DISCUSSION/SIGNIFICANCE OF IMPACT: This is a novel approach to the design and fabrication of intravaginal rings for the treatment of infertility. The use of CAD and the decoupling of release from mechanical properties allows for us to move away from the one-size one-dose fits all approach to IVRs.

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