Experimental Investigations for Surface Roughness and Dimensional Accuracy of FDM Components with Barrel Finishing

Previous studies on accuracy of three-dimensional (3D) printed model focused on full arch measurements at few points. The aim of this study was to examine the dimensional accuracy of 3D-printed models which were teeth-prepped for three-unit fixed prostheses, especially at margin and proximal contact areas. The prepped dental model was scanned with a desktop scanner. Using this reference file, test models were fabricated by digital light processing (DLP), Multi-Jet printing (MJP), and stereo-lithography apparatus (SLA) techniques. We calculated the accuracy (trueness and precision) of 3D-printed models on 3D planes, and deviations of each measured points at buccolingual and mesiodistal planes. We also analyzed the surface roughness of resin printed models. For overall 3D analysis, MJP showed significantly higher accuracy (trueness) than DLP and SLA techniques; however, there was not any statistically significant difference on precision. For deviations on margins of molar tooth and distance to proximal contact, MJP showed significantly accurate results; however, for a premolar tooth, there was no significant difference between the groups. 3D color maps of printed models showed contraction buccolingually, and surface roughness of the models fabricated by MJP technique was observed as the lowest. The accuracy of the 3D-printed resin models by DLP, MJP, and SLA techniques showed a clinically acceptable range to use as a working model for manufacturing dental prostheses

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Selective laser melting for improving quality characteristics of a prism shaped topology injection mould tool insert for the automotive industry

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406221989382 ◽

2021 ◽

pp. 095440622198938

Author(s):

Mennatallah F El Kashouty ◽

Allan EW Rennie ◽

Mootaz Ghazy ◽

Ahmed Abd El Aziz

Keyword(s):

Surface Roughness ◽

Selective Laser Melting ◽

Automotive Industry ◽

Injection Moulding ◽

Dimensional Accuracy ◽

Quality Characteristics ◽

Surface Topology ◽

Laser Melting ◽

Injection Mould ◽

Tool Insert

Manufacturing process constraints and design complexities are the main challenges that face the aftermarket automotive industry. For that reason, recently, selective laser melting (SLM) is being recognised as a viable approach in the fabrication of injection moulding tool inserts. Due to its versatility, SLM technology is capable of producing freeform designs. For the first reported time, in this study SLM is recognized for its novel application in overcoming fabrication complexities for prism shaped topology of a vehicle headlamp’s reflector injection moulding tool insert. Henceforth, performance measures of the SLM-fabricated injection mould tool insert is assessed in comparison to a CNC-milled counterpart to improve quality characteristics. Tests executed and detailed in this paper are divided into two stages; the first stage assesses both fabricated tool inserts in terms of manufacturability; the second stage assesses the functionality of the end-products by measuring the surface roughness, dimensional accuracy and light reflectivity from the vehicle reflectors. The results obtained show that employing SLM technology can offer an effective and efficient alternative to subtractive manufacturing, successfully producing tool inserts with complex surface topology. Significant benefits in terms of surface roughness, dimensional accuracy and product functionality were achieved through the use of SLM technology. it was concluded that the SLM-fabricated inserts products proved to have relatively lower values of surface roughness in comparison to their CNC counterparts.

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Additive manufacturing using fine wire-based laser metal deposition

Rapid Prototyping Journal ◽

10.1108/rpj-04-2019-0110 ◽

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.

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Formability of the Layer Additive Ceramic Part

Materials Science Forum ◽

10.4028/www.scientific.net/msf.594.241 ◽

2008 ◽

Vol 594 ◽

pp. 241-248 ◽

Cited By ~ 4

Author(s):

Fwu Hsing Liu ◽

Yunn Shiuan Liao ◽

Hsiu Ping Wang

Keyword(s):

Surface Roughness ◽

Laser Scanning ◽

Selective Laser Sintering ◽

Single Layer ◽

Dimensional Accuracy ◽

Scanning Speed ◽

Laser Sintering ◽

Single Line ◽

Laser Scanning Speed ◽

Silica Slurry

The material in powder state has long been used by selective laser sintering (SLS) for making rapid prototyping (RP) parts. A new approach to fabricate smoother surface roughness RP parts of ceramic material from slurry-sate has been developed in this study. The silica slurry was successfully laser-gelling in a self-developed laser sintering equipment. In order to overcome the insufficient bonding strength between layers, a strategy is proposed to generate ceramic parts from a single line, a single layer, to multi-layers of gelled cramic in this paper. It is found that when the overlap of each single line is 25% and the over-gel between layers is 30%, stronger and more accurate dimensional parts can be obtained under a laser power of 15W, a laser scanning speed of 250 mm/s, and a layer thickness of 0.1 mm. The 55:45 wt. % of the proportion between the silica powder and silica solution results in suitable viscosity of the ceramic slurries without precipitation. Furthermore, the effects of process parameters for the dimensional accuracy and surface roughness of the gelled parts are investigated and appropriate parameters are obtained.

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Investigation on Selective Laser Melting AlSi10Mg Cellular Lattice Strut: Molten Pool Morphology, Surface Roughness and Dimensional Accuracy

Materials ◽

10.3390/ma11030392 ◽

2018 ◽

Vol 11 (3) ◽

pp. 392 ◽

Cited By ~ 40

Author(s):

Xuesong Han ◽

Haihong Zhu ◽

Xiaojia Nie ◽

Guoqing Wang ◽

Xiaoyan Zeng

Keyword(s):

Surface Roughness ◽

Selective Laser Melting ◽

Molten Pool ◽

Dimensional Accuracy ◽

Laser Melting

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Experimental Investigations of the Machinability of Titanium Alloy TC4 with Different Hydrogen Contents

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.418-420.1307 ◽

2011 ◽

Vol 418-420 ◽

pp. 1307-1311

Author(s):

Jun Hu ◽

Yong Jie Bao ◽

Hang Gao ◽

Ke Xin Wang

Keyword(s):

Surface Roughness ◽

Titanium Alloy ◽

Cutting Force ◽

Hydrogen Content ◽

Experimental Results ◽

Cutting Conditions ◽

Experimental Investigations ◽

Cutting Condition ◽

The Given

The experiments were carried out in the paper to investigate the effect of adding hydrogen in titanium alloy TC4 on its machinability. The hydrogen contents selected were 0, 0.25%, 0.49%, 0.63%, 0.89% and 1.32%, respectively. Experiments with varing hydrogen contents and cutting conditions concurrently. Experimental results showed that the cutting force of the titanium alloy can be obviously reduced and the surface roughness can be improved by adding appropriate hydrogen in the material. In the given cutting condition, the titanium alloy TC4 with 0.49% hydrogen content showed better machinability.

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Experimental investigations into abrasive flow machining (AFM) of 3D printed ABS and PLA parts

Rapid Prototyping Journal ◽

10.1108/rpj-01-2021-0013 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Nitin Dixit ◽

Varun Sharma ◽

Pradeep Kumar

Keyword(s):

Surface Roughness ◽

Biomedical Applications ◽

Fused Deposition Modeling ◽

Experimental Investigations ◽

Future Research ◽

Content Type ◽

Abrasive Flow Machining ◽

Fused Deposition ◽

Cylindrical Parts ◽

3D Printed

Purpose The surface roughness of additively manufactured parts is usually found to be high. This limits their use in industrial and biomedical applications. Therefore, these parts required post-processing to improve their surface quality. The purpose of this study is to finish three-dimensional (3D) printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) parts using abrasive flow machining (AFM). Design/methodology/approach A hydrogel-based abrasive media has been developed to finish 3D printed parts. The developed abrasive media has been characterized for its rheology and thermal stability using sweep tests, thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The ABS and PLA cylindrical parts have been prepared using fused deposition modeling (FDM) and finished using AFM. The experiments were designed using Taguchi (L9 OA) method. The effect of process parameters such as extrusion pressure (EP), layer thickness (LT) and abrasive concentration (AC) was investigated on the amount of material removed (MR) and percentage improvement in surface roughness (%ΔRa). Findings The developed abrasive media was found to be effective for finishing FDM printed parts using AFM. The microscope images of unfinished and finished showed a significant improvement in surface topography of additively manufactures parts after AFM. The results reveal that AC is the most significant parameter during the finishing of ABS parts. However, EP and AC are the most significant parameters for MR and %ΔRa, respectively, during the finishing of PLA parts. Practical implications The FDM technology has applications in the biomedical, electronics, aeronautics and defense sectors. PLA has good biodegradable and biocompatible properties, so widely used in biomedical applications. The ventilator splitters fabricated using FDM have a profile similar to the shape used in the present study. Research limitations/implications The present study is focused on finishing FDM printed cylindrical parts using AFM. Future research may be done on the AFM of complex shapes and freeform surfaces printed using different additive manufacturing (AM) techniques. Originality/value An abrasive media consists of xanthan gum, locust bean gum and fumed silica has been developed and characterized. An experimental study has been performed by combining printing parameters of FDM and finishing parameters of AFM. A comparative analysis in MR and %ΔRa has been reported between 3D printed ABS and PLA parts.

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Ti6Al4V Parts Produced by Electron Beam Melting: Analysis of Dimensional Accuracy and Surface Roughness

Journal of Advanced Manufacturing Systems ◽

10.1142/s0219686720500067 ◽

2020 ◽

Vol 19 (01) ◽

pp. 107-130 ◽

Cited By ~ 2

Author(s):

R. Borrelli ◽

S. Franchitti ◽

C. Pirozzi ◽

L. Carrino ◽

L. Nele ◽

...

Keyword(s):

Surface Roughness ◽

Electron Beam ◽

Additive Manufacturing ◽

Electron Beam Melting ◽

Complex Shape ◽

Electron Beam Welding ◽

Raw Materials ◽

Dimensional Accuracy ◽

High Energy ◽

Quality Certification

Additive manufacturing (AM), applied to metal industry, is a family of processes that allows complex shape components to be realized from raw materials in the form of powders. Electron beam melting (EBM) is a relatively new additive manufacturing (AM) technology. Similar to electron-beam welding, EBM utilizes a high-energy electron beam as a moving heat source to melt metal powder, and 3D parts are produced in a layer-building fashion by rapid self-cooling. By EBM, it is possible to realize metallic complex shape components, e.g. fine network structures, internal cavities and channels, which are difficult to make by conventional manufacturing means. This feature is of particular interest in titanium industry in which numerous efforts are done to develop near net shape processes. In the field of mechanical engineering and, in particular, in the aerospace industry, it is crucial for quality certification purpose that components are produced through qualified and robust manufacturing processes ensuring high product repeatability. The contribution of the present work is to experimentally identify the EBM job parameters (sample orientation, location of the sample in the layer and height in the build chamber) that influence the dimensional accuracy and the surface roughness of the manufactured parts in Ti6Al4V. The repeatability of EBM is investigated too.

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Micromachining of Biolox Forte Ceramic Utilizing Combined Laser/Ultrasonic Processes

Materials ◽

10.3390/ma13163505 ◽

2020 ◽

Vol 13 (16) ◽

pp. 3505

Author(s):

Basem M. A. Abdo ◽

Syed Hammad Mian ◽

Abdualziz El-Tamimi ◽

Hisham Alkhalefah ◽

Khaja Moiduddin

Keyword(s):

Surface Roughness ◽

Material Removal ◽

Thermal Damage ◽

High Surface ◽

Dimensional Accuracy ◽

Ultrasonic Machining ◽

Rotary Ultrasonic Machining ◽

Machining Time ◽

Laser Beam Machining ◽

Wide Range

Micromachining has gained considerable interest across a wide range of applications. It ensures the production of microfeatures such as microchannels, micropockets, etc. Typically, the manufacturing of microchannels in bioceramics is a demanding task. The ubiquitous technologies, laser beam machining (LBM) and rotary ultrasonic machining (RUM), have tremendous potential. However, again, these machining methods do have inherent problems. LBM has issues concerning thermal damage, high surface roughness, and vulnerable dimensional accuracy. Likewise, RUM is associated with high machining costs and low material-removal rates. To overcome their limits, a synthesis of LBM and RUM processes known as laser rotary ultrasonic machining (LRUM) has been conceived. The bioceramic known as biolox forte was utilized in this investigation. The approach encompasses the exploratory study of the effects of fundamental input process parameters of LBM and RUM on the surface quality, machining time, and dimensional accuracy of the manufactured microchannels. The performance of LRUM was analyzed and the mechanism of LRUM tool wear was also investigated. The results revealed that the surface roughness, depth error, and width error is decreased by 88%, 70%, and 80% respectively in the LRUM process. Moreover, the machining time of LRUM is reduced by 85%.

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