Additive manufacturing in prosthesis development – a case study

2014 ◽  
Vol 20 (6) ◽  
pp. 480-489 ◽  
Author(s):  
Palash Kumar Maji ◽  
Amit Jyoti Banerjee ◽  
Partha Sarathi Banerjee ◽  
Sankar Karmakar
Keyword(s):  
Additive Manufacturing ◽  
Surface Finish ◽  
Dimensional Accuracy ◽  
Shrinkage Porosity ◽  
Cnc Machining ◽  
Shielding Effect ◽  
Patient Specific ◽  
Femoral Prosthesis ◽  
Metallic Component ◽  
Content Type

Purpose – The purpose of this paper was development of patient-specific femoral prosthesis using rapid prototyping (RP), a part of additive manufacturing (AM) technology, and comparison of its merits or demerits over CNC machining route. Design/methodology/approach – The customized femoral prosthesis was developed through computed tomography (CT)-3D CAD-RP-rapid tooling (RT)-investment casting (IC) route using a stereolithography apparatus (SLA-250) RP machine. A similar prosthesis was also developed through conventional CT-CAD-CAM-CNC, using RP models to check the fit before machining. The dimensional accuracy, surface finish, cost and time involvement were compared between these two routes. Findings – In both the routes, RP had an important role in checking the fit. Through the conventional machining route, higher-dimensional accuracies and surface finish were achieved. On the contrary, RP route involved lesser time and cost, with rougher surface finish on the prosthesis surface and less internal shrinkage porosity. The rougher surface finish of the prosthesis is favourable for bone ingrowths after implantation and porosity reduce the effective stiffness of the prosthesis, leading to reduced stress shielding effect after implantation. Research limitations/implications – As there is no AM machine for direct fabrication of metallic component like laser engineered net shaping and electron beam melting in our Institute, the metallic prosthesis was developed through RP-RT-IC route using the SLA-250 machine. Practical implications – The patient-specific prosthesis always provides better fit and favourable stress distribution, leading to longer life of the prosthesis. The described RP route can be followed to develop the customized prosthesis at lower price within the shortest time. Originality/value – The described methodology of customized prosthesis development through the AM route and its advantages are applicable for development of any metallic prostheses.

Additive manufacturing using fine wire-based laser metal deposition

2019 ◽  
Vol 26 (3) ◽  
pp. 473-483
Author(s):  
Muhammad Omar Shaikh ◽  
Ching-Chia Chen ◽  
Hua-Cheng Chiang ◽  
Ji-Rong Chen ◽  
Yi-Chin Chou ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
High Precision ◽  
Surface Finish ◽  
Dimensional Accuracy ◽  
Laser Metal Deposition ◽  
Cross Sectional ◽  
Content Type ◽  
Fine Wire

Purpose Using wire as feedstock has several advantages for additive manufacturing (AM) of metal components, which include high deposition rates, efficient material use and low material costs. While the feasibility of wire-feed AM has been demonstrated, the accuracy and surface finish of the produced parts is generally lower than those obtained using powder-bed/-feed AM. The purpose of this study was to develop and investigate the feasibility of a fine wire-based laser metal deposition (FW-LMD) process for producing high-precision metal components with improved resolution, dimensional accuracy and surface finish. Design/methodology/approach The proposed FW-LMD AM process uses a fine stainless steel wire with a diameter of 100 µm as the additive material and a pulsed Nd:YAG laser as the heat source. The pulsed laser beam generates a melt pool on the substrate into which the fine wire is fed, and upon moving the X–Y stage, a single-pass weld bead is created during solidification that can be laterally and vertically stacked to create a 3D metal component. Process parameters including laser power, pulse duration and stage speed were optimized for the single-pass weld bead. The effect of lateral overlap was studied to ensure low surface roughness of the first layer onto which subsequent layers can be deposited. Multi-layer deposition was also performed and the resulting cross-sectional morphology, microhardness, phase formation, grain growth and tensile strength have been investigated. Findings An optimized lateral overlap of about 60-70% results in an average surface roughness of 8-16 µm along all printed directions of the X–Y stage. The single-layer thickness and dimensional accuracy of the proposed FW-LMD process was about 40-80 µm and ±30 µm, respectively. A dense cross-sectional morphology was observed for the multilayer stacking without any visible voids, pores or defects present between the layers. X-ray diffraction confirmed a majority austenite phase with small ferrite phase formation that occurs at the junction of the vertically stacked beads, as confirmed by the electron backscatter diffraction (EBSD) analysis. Tensile tests were performed and an ultimate tensile strength of about 700-750 MPa was observed for all samples. Furthermore, multilayer printing of different shapes with improved surface finish and thin-walled and inclined metal structures with a minimum achievable resolution of about 500 µm was presented. Originality/value To the best of the authors’ knowledge, this is the first study to report a directed energy deposition process using a fine metal wire with a diameter of 100 µm and can be a possible solution to improving surface finish and reducing the “stair-stepping” effect that is generally observed for wires with a larger diameter. The AM process proposed in this study can be an attractive alternative for 3D printing of high-precision metal components and can find application for rapid prototyping in a range of industries such as medical and automotive, among others.

Rethinking reverse logistics: role of additive manufacturing technology in metal remanufacturing

2019 ◽  
Vol 31 (1) ◽  
pp. 124-144 ◽  
Author(s):  
Danielle Strong ◽  
Michael Kay ◽  
Thomas Wakefield ◽  
Issariya Sirichakwal ◽  
Brett Conner ◽  
...  
Keyword(s):  
Supply Chain ◽  
Additive Manufacturing ◽  
Facility Location ◽  
Reverse Logistics ◽  
Small And Medium Enterprises ◽  
Real Data ◽  
Cnc Machining ◽  
Numerical Control ◽  
Content Type ◽  
The Usa

Purpose Although the adoption of metal additive manufacturing (AM) for production has continuously grown, in-house access to production grade metal AM systems for small and medium enterprises (SMEs) is a major challenge due to costs of acquiring metal AM systems, specifically powder bed fusion AM. On the other hand, AM technology in directed energy deposition (DED) has been evolving in both: processing capabilities and adaptable configuration for integration within existing traditional machines that are available in most SME manufacturing facilities, e.g. computer numerical control (CNC) machining centers. Integrating DED with conventional processes such as machining and grinding into Hybrid AM is well suited for remanufacturing of metal parts. The paper aims to discuss these issues. Design/methodology/approach Classical facility location models are employed to understand the effects of SMEs adopting DED systems to offer remanufacturing services. This study identifies strategically located counties in the USA to advance hybrid AM for reverse logistics using North American Industry Classification System (NAICS) data on geographical data, demand, fixed and transportation costs. A case study is also implemented to explore its implications on remanufacturing of high-value parts on the reverse logistics supply chain using an aerospace part and NAICS data on aircraft maintenance, repair and overhaul facilities. Findings The results identify the candidate counties, their allocations, allocated demand and total costs. Offering AM remanufacturing services to traditional manufacturers decreases costs for SMEs in the supply chain by minimizing expensive new part replacement. The hubs also benefit from hybrid AM to repair their own parts and tools. Originality/value This research provides a unique analysis on reverse logistics through hybrid AM focused on remanufacturing rather than manufacturing. Facility location using real data is used to obtain results and offers insights into integrating AM for often overlooked aspect of remanufacturing. The study shows that SMEs can participate in the evolving AM economy through remanufacturing services using significantly lower investment costs.

Polyvinylidene fluoride (PVDF) as a feedstock for material extrusion additive manufacturing

2020 ◽  
Vol 26 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Niknam Momenzadeh ◽  
Hadi Miyanaji ◽  
Daniel Allen Porter ◽  
Thomas Austin Berfield
Keyword(s):  
Additive Manufacturing ◽  
Polyvinylidene Fluoride ◽  
Mechanical Response ◽  
Dimensional Accuracy ◽  
Piezoelectric Response ◽  
Content Type ◽  
Material Extrusion ◽  
Deposition Parameters ◽  
The Individual ◽  
Deposition Conditions

Purpose This study aims to investigate the material extrusion additive manufacturing (MEAM) deposition parameters for creating viable 3-D printed polyvinylidene fluoride (PVDF) structures with a balanced mix of mechanical and electrical properties. Design/methodology/approach Different combinations of deposition conditions are tested, and the influence of these parameters on the final dimensional accuracy, semi-crystalline phase microstructure and effective mechanical strength of MEAM homopolymer PVDF printed parts is experimentally assessed. Considering printed part integrity, appearance, print time and dimensional accuracy, MEAM parameters for PVDF are suggested. Findings A range of viable printing parameters for MEAM fabricated PVDF Kynar 740 objects of different heights and in-plane length dimensions was determined. For PVDF structures printed under the suggested conditions, the mechanical response and the microstructure development related to Piezoelectric response are reported. Originality/value This research first reports on a range of parameters that have been confirmed to facilitate effective MEAM printing of 3-D PVDF objects, presents effects of the individual parameters and gives the mechanical and microstructure properties of PVDF structures fabricated under the suggested deposition conditions.

Stereo vision-based repair of metallic components

2017 ◽  
Vol 23 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Renwei Liu ◽  
Zhiyuan Wang ◽  
Todd Sparks ◽  
Frank Liou ◽  
Cedo Nedic
Keyword(s):  
Stereo Vision ◽  
Tool Path ◽  
Cnc Machining ◽  
Displacement Sensor ◽  
Laser Displacement Sensor ◽  
Laser Metal Deposition ◽  
Metallic Component ◽  
Content Type ◽  
Defect Area ◽  
Automated Alignment

Purpose This paper aims to investigate a stereo vision-based hybrid (additive and subtractive) manufacturing process using direct laser metal deposition, computer numerical control (CNC) machining and in-process scanning to repair metallic components automatically. The focus of this work was to realize automated alignment and adaptive tool path generation that can repair metallic components after a single setup. Design/methodology/approach Stereo vision was used to detect the defect area for automated alignment. After the defect is located, a laser displacement sensor is used to scan the defect area before and after laser metal deposition. The scan is then processed by an adaptive algorithm to generate a tool path for repairing the defect. Findings The hybrid manufacturing processes for repairing metallic component combine the advantages of free-form fabrication from additive manufacturing with the high-accuracy offered by CNC machining. A Ti-6Al-4V component with a manufacturing defect was repaired by the proposed process. Compared to previous research on repairing worn components, introducing stereo vision and laser scanning dramatically simplifies the manual labor required to extract and reconstruct the defect area’s geometry. Originality/value This paper demonstrates an automated metallic component repair process by integrating stereo vision and a laser displacement sensor into a hybrid manufacturing system. Experimental results and microstructure analysis shows that the defect area could be repaired feasibly and efficiently with acceptable heat affected zone using the proposed approach.

A review of melt extrusion additive manufacturing processes: II. Materials, dimensional accuracy, and surface roughness

2015 ◽  
Vol 21 (3) ◽  
pp. 250-261 ◽  
Author(s):  
Brian N. Turner ◽  
Scott A Gold
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Product Design ◽  
Fused Deposition Modeling ◽  
Dimensional Accuracy ◽  
Design Parameters ◽  
Content Type ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Am Processes

Purpose – The purpose of this paper is to critically review the literature related to dimensional accuracy and surface roughness for fused deposition modeling and similar extrusion-based additive manufacturing or rapid prototyping processes. Design/methodology/approach – A systematic review of the literature was carried out by focusing on the relationship between process and product design parameters and the dimensional and surface properties of finished parts. Methods for evaluating these performance parameters are also reviewed. Findings – Fused deposition modeling® and related processes are the most widely used polymer rapid prototyping processes. For many applications, resolution, dimensional accuracy and surface roughness are among the most important properties in final parts. The influence of feedstock properties and system design on dimensional accuracy and resolution is reviewed. Thermal warping and shrinkage are often major sources of dimensional error in finished parts. This phenomenon is explored along with various approaches for evaluating dimensional accuracy. Product design parameters, in particular, slice height, strongly impact surface roughness. A geometric model for surface roughness is also reviewed. Originality/value – This represents the first review of extrusion AM processes focusing on dimensional accuracy and surface roughness. Understanding and improving relationships between materials, design parameters and the ultimate properties of finished parts will be key to improving extrusion AM processes and expanding their applications.

Dimensional Accuracy in PolyJet Printing: A Literature Review

2019 ◽  
Author(s):  
Ketan Thakare ◽  
Xingjian Wei ◽  
Zhijian Pei
Keyword(s):  
Additive Manufacturing ◽  
Layer Thickness ◽  
Surface Finish ◽  
Dimensional Accuracy ◽  
High Dimensional ◽  
Control Variables ◽  
Current Trends ◽  
Manufacturing Methods ◽  
Polyjet Printing ◽  
Part Orientation

Abstract PolyJet printing process is one of the additive manufacturing methods to print parts with high dimensional accuracy. To date, dimensional accuracies of such process have been investigated by a number of studies. This review will summarize those studies, and identify current trends. With respect to methods of measurements used in the reported studies, it is noted that no special preference is given to use of any method. In addition, the effects of four control variables of PolyJet process: part orientation, layer thickness, surface finish type and materials, on dimensional accuracy are noted based on the results of reported studies. There is consistency in results in studies considering control variables of layer thickness, surface finish type and materials. However, the results are inconsistent in studies considering part orientation.

Development of a patient-specific immobilisation facemask for radiation therapy using additive manufacturing, pressure sensors and topology optimisation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Amirhossein Asfia ◽  
James I. Novak ◽  
Bernard Rolfe ◽  
Tomas Kron
Keyword(s):  
Additive Manufacturing ◽  
Head Movement ◽  
Pressure Sensors ◽  
Sensor Data ◽  
Patient Specific ◽  
Topology Optimisation ◽  
Content Type ◽  
Fused Deposition ◽  
And Topology ◽  
Mask Design

Purpose Radiotherapy relies on the delivery of radiation to cancer cells with millimetre accuracy, and immobilisation of patients is essential to minimise unwanted damage to surrounding healthy cells due to patient movement. Traditional thermoformed face masks can be uncomfortable and stressful for patients and may not be accurately fitted. The purpose of this study was to use 3D scanning and additive manufacturing to digitise this workflow and improve patient comfort and treatment outcomes. Design/methodology/approach The head of a volunteer was scanned using an Artec Leo optical scanner (Artec, Luxembourg) and ANSYS (Ansys, Canonsburg, USA) software was used to make two 3D models of the mask: one with a nose bridge and one open as would be used with optical surface guidance. Data based on measurements from ten pressure sensors around the face was used to perform topology optimisation, with the best designs 3D printed using fused deposition modelling (FDM) and tested on the volunteer with embedded pressure sensors. Findings The two facemasks proved to be significantly different in terms of restricting head movement inside the masks. The optimised mask with a nose bridge effectively restricted head movement in roll and yaw orientations and exhibited minimal deformation as compared to the open mask design and the thermoformed mask. Originality/value The proposed workflow allows customisation of masks for radiotherapy immobilisation using additive manufacturing and topology optimisation based on collected pressure sensor data. In the future, sensors could be embedded in masks to provide real-time feedback to clinicians during treatment.

Quantifying accuracy of a concept laser metal additive machine through the NIST test artifact

2019 ◽  
Vol 25 (2) ◽  
pp. 221-231
Author(s):  
Jason M. Weaver ◽  
T.J. Barton ◽  
John Linn ◽  
Derrik Jenkins ◽  
Michael P. Miles ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Industry ◽  
Optical Measurement ◽  
Dimensional Accuracy ◽  
Additive Process ◽  
Content Type ◽  
System A ◽  
Inclined Surfaces ◽  
Touch Probe ◽  
Metal Additive

Purpose The purpose of this paper is to describe the use of a test artifact proposed by NIST to quantify the dimensional accuracy of a metal additive manufacturing process. Insights from this paper are given concerning both the performance of the machine, a concept laser Mlab cusing machine, and the applicability of the NIST test artifact in characterizing accuracy. Recommendations are given for improving the artifact and standardizing a process for evaluating dimensional accuracy across the additive manufacturing industry. Design/methodology/approach Three builds of the NIST additive manufacturing test artifact were fabricated in 316 stainless steel on a concept laser Mlab cusing machine. The paper follows the procedure described by NIST for characterizing dimensional accuracy of the additive process. Features including pins, holes and staircase flats of various sizes were measured using an optical measurement system, a touch probe and a profilometer. Findings This paper describes the accuracy of printed features’ size and position on the test artifact, as well as surface finish on flat and inclined surfaces. Trends in variation of these dimensions are identified, along with possible root causes and remedies. This paper also describes several strengths and weaknesses in the design of the test artifact and the proposed measurement strategy, with recommendations on how to improve and standardize the process. Originality/value This paper reviews a previously proposed design and process for measuring the capabilities of additive manufacturing processes. It also suggests improvements that can be incorporated into future designs and standardized across the industry.

Comparing environmental impacts of additive manufacturing vs traditional machining via life-cycle assessment

2015 ◽  
Vol 21 (1) ◽  
pp. 14-33 ◽  
Author(s):  
Jeremy Faludi ◽  
Cindy Bayley ◽  
Suraj Bhogal ◽  
Myles Iribarne
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Additive Manufacturing ◽  
Environmental Impacts ◽  
Surface Finish ◽  
Numerical Control ◽  
Cutting Fluid ◽  
Content Type ◽  
Electricity Use

Purpose – The purpose of this study is to compare the environmental impacts of two additive manufacturing machines to a traditional computer numerical control (CNC) milling machine to determine which method is the most sustainable. Design/methodology/approach – A life-cycle assessment (LCA) was performed, comparing a Haas VF0 CNC mill to two methods of additive manufacturing: a Dimension 1200BST FDM and an Objet Connex 350 “inkjet”/“polyjet”. The LCA’s functional unit was the manufacturing of two specific parts in acrylonitrile butadiene styrene (ABS) plastic or similar polymer, as required by the machines. The scope was cradle to grave, including embodied impacts, transportation, energy used during manufacturing, energy used while idling and in standby, material used in final parts, waste material generated, cutting fluid for CNC, and disposal. Several scenarios were considered, all scored using the ReCiPe Endpoint H and IMPACT 2002+ methodologies. Findings – Results showed that the sustainability of additive manufacturing vs CNC machining depends primarily on the per cent utilization of each machine. Higher utilization both reduces idling energy use and amortizes the embodied impacts of each machine. For both three-dimensional (3D) printers, electricity use is always the dominant impact, but for CNC at maximum utilization, material waste became dominant, and cutting fluid was roughly on par with electricity use. At both high and low utilization, the fused deposition modeling (FDM) machine had the lowest ecological impacts per part. The inkjet machine sometimes performed better and sometimes worse than CNC, depending on idle time/energy and on process parameters. Research limitations/implications – The study only compared additive manufacturing in plastic, and did not include other additive manufacturing technologies, such as selective laser sintering or stereolithography. It also does not include post-processing that might bring the surface finish of FDM parts up to the quality of inkjet or CNC parts. Practical implications – Designers and engineers seeking to minimize the environmental impacts of their prototypes should share high-utilization machines, and are advised to use FDM machines over CNC mills or polyjet machines if they provide sufficient quality of surface finish. Originality/value – This is the first paper quantitatively comparing the environmental impacts of additive manufacturing with traditional machining. It also provides a more comprehensive measurement of environmental impacts than most studies of either milling or additive manufacturing alone – it includes not merely CO2 emissions or waste but also acidification, eutrophication, human toxicity, ecotoxicity and other impact categories. Designers, engineers and job shop managers may use the results to guide sourcing or purchasing decisions related to rapid prototyping.

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