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.

scholarly journals Metal Machining—Recent Advances, Applications, and Challenges

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 580
Author(s):  
Francisco J. G. Silva
Keyword(s):  
Surface Finish ◽  
Manufacturing Process ◽  
Dimensional Accuracy ◽  
Machining Process ◽  
High Dimensional ◽  
Manufacturing Processes ◽  
Recent Advances ◽  
Metal Machining ◽  
Rapid Manufacture

Though new manufacturing processes that revolutionize the landscape regarding the rapid manufacture of parts have recently emerged, the machining process remains alive and up-to-date in this context, always presenting itself as a manufacturing process with several variants and allowing for high dimensional accuracy and high levels of surface finish [...]

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.

scholarly journals Analysis and Optimization of Dimensional Accuracy and Porosity of High Impact Polystyrene Material Printed by FDM Process: PSO, JAYA, Rao, and Bald Eagle Search Algorithms

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7479
Author(s):  
Manjunath Patel Gowdru Chandrashekarappa ◽  
Ganesh Ravi Chate ◽  
Vineeth Parashivamurthy ◽  
Balakrishnamurthy Sachin Kumar ◽  
Mohd Amaan Najeeb Bandukwala ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Shell Thickness ◽  
Dimensional Accuracy ◽  
High Impact ◽  
Bald Eagle ◽  
Proper Function ◽  
Control Variables ◽  
Fused Deposition ◽  
High Impact Polystyrene ◽  
Cylindricity Error

High impact polystyrene (HIPS) material is widely used for low-strength structural applications. To ensure proper function, dimensional accuracy and porosity are at the forefront of industrial relevance. The dimensional accuracy cylindricity error (CE) and porosity of printed parts are influenced mainly by the control variables (layer thickness, shell thickness, infill density, print speed of the fused deposition modeling (FDM) process). In this study, a central composite design (CCD) matrix was used to perform experiments and analyze the complete insight information of the process (control variables influence on CE and porosity of FDM parts). Shell thickness for CE and infill density for porosity were identified as the most significant factors. Layer thickness interaction with shell thickness, infill density (except for CE), and print speed were found to be significant for both outputs. The interaction factors, i.e., shell thickness and infill density, were insignificant (negligible effect) for both outputs. The models developed produced a better fit for regression with an R2 equal to 94.56% for CE, and 99.10% for porosity, respectively. Four algorithms (bald eagle search optimization (BES), particle swarm optimization (PSO), RAO-3, and JAYA) were applied to determine optimal FDM conditions while examining six case studies (sets of weights assigned for porosity and CE) focused on minimizing both CE and porosity. BES and RAO-3 algorithms determined optimal conditions (layer thickness: 0.22 mm; shell thickness: 2 mm; infill density: 100%; print speed: 30 mm/s) at a reduced computation time equal to 0.007 s, differing from JAYA and PSO, which resulted in an experimental CE of 0.1215 mm and 2.5% of porosity in printed parts. Consequently, BES and RAO-3 algorithms are efficient tools for the optimization of FDM parts.

scholarly journals Analysis of Density, Roughness, and Accuracy of the Atomic Diffusion Additive Manufacturing (ADAM) Process for Metal Parts

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4122 ◽  
Author(s):  
Manuela Galati ◽  
Paolo Minetola
Keyword(s):  
Additive Manufacturing ◽  
Layer Thickness ◽  
Dimensional Accuracy ◽  
Raw Material ◽  
Atomic Diffusion ◽  
Powder Bed ◽  
Metal Parts ◽  
Unique System ◽  
Am Processes ◽  
Metal Additive

Atomic Diffusion Additive Manufacturing (ADAM) is a recent layer-wise process patented by Markforged for metals based on material extrusion. ADAM can be classified as an indirect additive manufacturing process in which a filament of metal powder encased in a plastic binder is used. After the fabrication of a green part, the plastic binder is removed by the post-treatments of washing and sintering (frittage). The aim of this work is to provide a preliminary characterisation of the ADAM process using Markforged Metal X, the unique system currently available on the market. Particularly, the density of printed 17-4 PH material is investigated, varying the layer thickness and the sample size. The dimensional accuracy of the ADAM process is evaluated using the ISO IT grades of a reference artefact. Due to the deposition strategy, the final density of the material results in being strongly dependent on the layer thickness and the size of the sample. The density of the material is low if compared to the material processed by powder bed AM processes. The superficial roughness is strongly dependent upon the layer thickness, but higher than that of other metal additive manufacturing processes because of the use of raw material in the filament form. The accuracy of the process achieves the IT13 grade that is comparable to that of traditional processes for the production of semi-finished metal parts.

scholarly journals Comparison of different additive manufacturing patterns on the performance of rapid vacuum casting for mating parts via the Taguchi method

2020 ◽  
Vol 14 (1) ◽  
pp. 6417-6429 ◽  
Author(s):  
Nur Nabilah Mohd Mustafa ◽  
Aini Zuhra Abdul Kadir ◽  
N. H. Akhmal Ngadiman ◽  
A. Ma'aram ◽  
K. Zakaria
Keyword(s):  
Additive Manufacturing ◽  
Taguchi Method ◽  
Surface Finish ◽  
Fused Deposition Modeling ◽  
Dimensional Accuracy ◽  
Casting Process ◽  
Vacuum Casting ◽  
Fused Deposition ◽  
Small Series ◽  
Master Pattern

Rapid vacuum casting has been proven to be a successful method in producing high-quality parts in small series. However, a challenge lies in the selection of proper Additive Manufacturing (AM) technologies for the development of a master pattern for the vacuum casting process. Each AM technologies differ from one another in terms of dimensional accuracy, surface finish, cost and lead times. The aim of this study is to investigate the performance of casting mating parts based on different additive manufacturing patterns for small batch. Three types of AM-based patterns: Fused Deposition Modeling (FDM), Stereolithography (SLA) and Multi-Jet Fusion (MJF) were compared. The Taguchi method, Signal to Noise ratio (S/N), Analysis of Variance (ANOVA) and T-test were conducted in determining the optimized parameters. From the findings, curing time is shown to be a significant parameter for dimensional accuracy and surface finish. Dimensional deviation varies in different directions of parts. For surface finish, there was only a slight change from the master pattern whereas the surface roughness of casting parts decreased within the range 0.23% to 2.85%. Tolerance grades for the selected dimensions of the parts were in the permissible range, based on ISO286-1:2010. When using distinct kinds of AM patterns to create replacement components, design tolerance is needed. It was suggested to select AM technology similar to that had been used for the original components.  Battery cover was selected as a case study to represent the mating application parts.

Rapid Investment Casting: Design and Manufacturing Technologies

2019 ◽  
Author(s):  
Christopher T. Richard ◽  
Tsz-Ho Kwok
Keyword(s):  
Additive Manufacturing ◽  
Fatigue Strength ◽  
3D Printing ◽  
Surface Finish ◽  
Investment Casting ◽  
Biomedical Engineering ◽  
Design And Manufacturing ◽  
Manufacturing Methods ◽  
Manufacturing Technologies ◽  
Casting Design

Abstract With the emergence of new metal AM (additive manufacturing) methods, rapid IC (investment casting), a variation of conventional investment casting has been a popular topic of research in the fields of: aerospace, dentistry and biomedical engineering. RIC (Rapid investment casting) takes advantage of the additive nature of 3D printing for pattern making which allows for more complex castings than traditional investment casting. RIC is a manufacturing process that combines the casting knowledge accumulated over five thousand years with relatively novel AM knowledge. The result is a process that can compete with newer metal AM methods with the added benefits of excellent surface finish, fatigue strength and the ability to create parts from almost any metal or metal alloy. This article will focus on research advancements in investment casting, AM and all the topics that are closely related to optimizing these two processes. Beyond that, aerospace, dentistry and biomedical engineering advancements using investment casting will be reviewed.

Part Build Orientation Optimization and Neural Network-Based Geometry Compensation for Additive Manufacturing Process

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Sushmit Chowdhury ◽  
Kunal Mhapsekar ◽  
Sam Anand
Keyword(s):  
Neural Network ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Surface Finish ◽  
Quality Measurement ◽  
Dimensional Accuracy ◽  
Build Orientation ◽  
Part Quality ◽  
Heating And Cooling ◽  
Orientation Optimization

Significant advancements in the field of additive manufacturing (AM) have increased the popularity of AM in mainstream industries. The dimensional accuracy and surface finish of parts manufactured using AM depend on the AM process and the accompanying process parameters. Part build orientation is one of the most critical process parameters, since it has a direct impact on the part quality measurement metrics such as cusp error, manufacturability concerns for geometric features such as thin regions and small fusible openings, and support structure parameters. In conjunction with the build orientation, the cyclic heating and cooling of the material involved in the AM processes lead to nonuniform deformations throughout the part. These factors cumulatively affect the design conformity, surface finish, and the postprocessing requirements of the manufactured parts. In this paper, a two-step part build orientation optimization and thermal compensation methodology is presented to minimize the geometric inaccuracies resulting in the part during the AM process. In the first step, a weighted optimization model is used to determine the optimal build orientation for a part with respect to the aforementioned part quality and manufacturability metrics. In the second step, a novel artificial neural network (ANN)-based geometric compensation methodology is used on the part in its optimal orientation to make appropriate geometric modifications to counteract the thermal effects resulting from the AM process. The effectiveness of this compensation is assessed on an example part using a new point cloud to part conformity metric and shows significant improvements in the manufactured part's geometric accuracy.

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.

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