The Influence of the Material Type and the Placement in the Print Chamber on the Roughness of MJF-Printed 3D Objects

This paper describes a surface-roughness study performed on samples manufactured additively using the Multi Jet Fusion (MJF) technology. The samples were divided into three groups based on the material used in the process: polypropylene (PP), thermoplastic polyurethane (TPU), and polyamide 11 (PA11). Subsequently, they were tested by means of a roughness-measuring system, which made it possible to determine the typical surface roughness parameters (Ra, Rq, Rz). The tests were designed to examine whether the placement and orientation of 3D objects while printing, in connection with the material used, can significantly influence the surface quality of MJF-printed objects. The results show that the TPU samples have a surface roughness much higher than the PP and PA11 ones, which exhibit roughness levels very similar to each other. It can also be concluded that surfaces printed vertically (along the Z-axis) tend to be less smooth—similarly to the surfaces of objects made of TPU located in the central zones of the print chamber during printing. This information may be of value in cases where low surface roughness is preferred (e.g., manufacturing patient-specific orthoses), although this particular study does not focus on one specific application.

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Comparison of Experimental Stamping Punch Machinability Made out of Unconventional Materials

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.635.81 ◽

2014 ◽

Vol 635 ◽

pp. 81-84

Author(s):

Peter Ižol ◽

Dagmar Draganovská ◽

Juraj Hudák ◽

Miroslav Tomáš ◽

Jozef Beňo

Keyword(s):

Surface Roughness ◽

Surface Quality ◽

Experimental Work ◽

Roughness Parameters ◽

Scallop Height ◽

Shaped Surface ◽

Final Surface ◽

Surface Roughness Parameters ◽

Cam Software

The paper describes experimental stamping punch production from the view machinability and quality of stamping punch active surfaces. The tin car-body stamping punch has been chosen as a subject of experimental work. Two unconventional materials such as Textit J and Fibroflex 5 have been chosen for stamping punch. Milling strategies have been proposed, optimized and verified using CAM software SolidCAM considering the maximum Scallop Height. The final surface quality on selected areas of stamping punch shaped surface has been evaluated by surface roughness parameters Ra and Rz. These have been compared to Scallop Height set in CAM software. Manufactured areas on shaped surface were optically evaluated as well.

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A Comprehensive Investigation on 3D Printing of Polyamide 11 and Thermoplastic Polyurethane via Multi Jet Fusion

Polymers ◽

10.3390/polym13132139 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2139

Author(s):

Wei Shian Tey ◽

Chao Cai ◽

Kun Zhou

Keyword(s):

Tensile Strength ◽

Flexural Strength ◽

Wear Rate ◽

Mechanical Performance ◽

Thermoplastic Polyurethane ◽

Print Quality ◽

Polyamide 11 ◽

Powder Bed

Multi Jet Fusion (MJF) is a recently developed polymeric powder bed fusion (PBF) additive manufacturing technique that has received considerable attention in the industrial and scientific community due to its ability to fabricate functional and complex polymeric parts efficiently. In this work, a systematic characterization of the physicochemical properties of MJF-certified polyamide 11 (PA11) and thermoplastic polyurethane (TPU) powder was conducted. The mechanical performance and print quality of the specimens printed using both powders were then evaluated. Both PA11 and TPU powders showed irregular morphology with sharp features and had broad particle size distribution, but such features did not impair their printability significantly. According to the DSC scans, the PA11 specimen exhibited two endothermic peaks, while the TPU specimen exhibited a broad endothermic peak (116–150 °C). The PA11 specimens possessed the highest tensile strength in the Z orientation, as opposed to the TPU specimens which possessed the lowest tensile strength along the same orientation. The flexural properties of the PA11 and TPU specimens displayed a similar anisotropy where the flexural strength was highest in the Z orientation and lowest in the X orientation. The porosity values of both the PA11 and the TPU specimens were observed to be the lowest in the Z orientation and highest in the X orientation, which was the opposite of the trend observed for the flexural strength of the specimens. The PA11 specimen possessed a low coefficient of friction (COF) of 0.13 and wear rate of 8.68 × 10−5 mm3/Nm as compared to the TPU specimen, which had a COF of 0.55 and wear rate of 0.012 mm3/Nm. The PA11 specimens generally had lower roughness values on their surfaces (Ra < 25 μm), while the TPU specimens had much rougher surfaces (Ra > 40 μm). This investigation aims to uncover and explain phenomena that are unique to the MJF process of PA11 and TPU while also serving as a benchmark against similar polymeric parts printed using other PBF processes.

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Observation in the Surface Roughness of Silicon Wafer during Semi-Fixed Abrasive Machining with Large Grains

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.69-70.253 ◽

2009 ◽

Vol 69-70 ◽

pp. 253-257

Author(s):

Ping Zhao ◽

Jia Jie Chen ◽

Fan Yang ◽

K.F. Tang ◽

Ju Long Yuan ◽

...

Keyword(s):

Surface Roughness ◽

Surface Quality ◽

Silicon Wafer ◽

Processing Parameters ◽

Wafer Surface ◽

Abrasive Machining ◽

Fixed Abrasive ◽

Is Failure ◽

Better Than

Semi-fixed abrasive is a novel abrasive. It has a ‘trap’ effect on the hard large grains that can prevent defect effectively on the surface of the workpiece which is caused by large grains. In this paper, some relevant experiments towards silicon wafers are carried out under the different processing parameters on the semi-fixed abrasive plates, and 180# SiC is used as large grains. The processed workpieces’ surface roughness Rv are measured. The experimental results show that the surface quality of wafer will be worse because of higher load and faster rotating velocity. And it can make a conclusion that the higher proportion of bond of the plate, the weaker of the ‘trap’ effect it has. Furthermore the wet environment is better than dry for the wafer surface in machining. The practice shows that the ‘trap’ effect is failure when the workpiece is machined by abrasive plate which is 4.5wt% proportion of bond in dry lapping.

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The mechanism of process parameters influencing the AlSi10Mg side surface quality fabricated via laser powder bed fusion

Rapid Prototyping Journal ◽

10.1108/rpj-11-2020-0266 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Shimin Dai ◽

Hailong Liao ◽

Haihong Zhu ◽

Xiaoyan Zeng

Keyword(s):

Surface Roughness ◽

Surface Quality ◽

Process Parameters ◽

Laser Power ◽

Side Surface ◽

Laser Powder Bed Fusion ◽

Scanning Velocity ◽

Content Type ◽

Powder Bed

Purpose For the laser powder bed fusion (L-PBF) technology, the side surface quality is essentially important for industrial applicated parts, such as the inner flow parts. Contour is generally adopted at the parts’ outline to enhance the side surface quality. However, the side surface roughness (Ra) is still larger than 10 microns even with contour in previous studies. The purpose of this paper is to study the influence of contour process parameters, laser power and scanning velocity on the side surface quality of the AlSi10Mg sample. Design/methodology/approach Using L-PBF technology to manufacture AlSi10Mg samples under different contour process parameters, use a laser confocal microscope to capture the surface information of the samples, and obtain the surface roughness Ra and the maximum surface height Rz of each sample after analysis and processing. Findings The results show that the side surface roughness decreases with the increase of the laser power at the fixed scanning velocity of 1,000 mm/s, the side surface roughness Ra stays within the error range as the contour velocity increases. It is found that the Ra increases with the scanning velocity increasing and the greater the laser power with the greater Ra increases when the laser power of contour process parameters is 300 W, 350 W and 400 W. The Rz maintain growth with the contour scanning velocity increasing at constant laser power. The continuous uniform contour covers the pores in the molten pool of the sample edge and thus increase the density of the sample. Two mechanisms named “Active adhesion” and “Passive adhesion” cause sticky powder. Originality/value Formation of a uniform and even contour track is key to obtain the good side surface quality. The side surface quality is determined by the uniformity and stability of the contour track when the layer thickness is fixed. These research results can provide helpful guidance to improve the surface quality of L-PBF manufactured parts.

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Investigation of the Effects of Technological Parameters on Surface Roughness in Extrusion Bars of Aluminum Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.889.155 ◽

2019 ◽

Vol 889 ◽

pp. 155-160

Author(s):

Trong Mai Nguyen ◽

Đuc Quy Tran ◽

Van Nghe Pham ◽

Van Canh Nguyen

Keyword(s):

Surface Roughness ◽

Aluminum Alloy ◽

Surface Quality ◽

Research Work ◽

Extrusion Process ◽

Optimal Parameters ◽

Technological Parameters

In this research work, the result of the effects of technological parameters on surface roughness in extrusion bars of aluminum alloy were pesented. The results of this study may be used for choosing optimal parameters of extrusion process so that surface quality of extruded bar was improved.

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Impact of Structural Defects on the Surface Quality of Hardwood Species Sliced Veneers

Applied Sciences ◽

10.3390/app10186265 ◽

2020 ◽

Vol 10 (18) ◽

pp. 6265

Author(s):

Vasiliki Kamperidou ◽

Efstratios Aidinidis ◽

Ioannis Barboutis

Keyword(s):

Surface Roughness ◽

Surface Quality ◽

Wood Species ◽

Research Work ◽

Structural Defects ◽

Material Surface ◽

Typical Structure ◽

Hardwood Species ◽

The Impact

The surface roughness constitutes one of the most critical properties of wood and wood veneers for their extended utilization, affecting the bonding ability of the veneers with one another in the manufacturing of wood composites, the finishing, coating and preservation processes, and the appearance and texture of the material surface. In this research work, logs of five significant European hardwood species (oak, chestnut, ash, poplar, cherry) of Balkan origin were sliced into decorative veneers. Their surface roughness was examined by applying a stylus tracing method, on typical wood structure areas of each wood species, as well as around the areas of wood defects (knots, decay, annual rings irregularities, etc.), to compare them and assess the impact of the defects on the surface quality of veneers. The chestnut veneers presented the smoothest surfaces, while ash veneers, despite the higher density, recorded the highest roughness. In most of the cases, the roughness was found to be significantly lower around the defects, compared to the typical structure surfaces, probably due to lower porosity, higher density and the presence of tensile wood. The results reveal that the presence of defects does not affect the roughness of the veneers and increases neither the processing requirements of the veneer sheets before finishing, nor the respective production cost of veneers and the veneer-based wood panels. The high utilization prospects of the examined wood species in veneer production, even those bearing various defects, is highlighted.

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Surface Roughness Investigation of Poly-Jet 3D Printing

Mathematics ◽

10.3390/math8101758 ◽

2020 ◽

Vol 8 (10) ◽

pp. 1758

Author(s):

Nectarios Vidakis ◽

Markos Petousis ◽

Nikolaos Vaxevanidis ◽

John Kechagias

Keyword(s):

Surface Roughness ◽

3D Printing ◽

Surface Quality ◽

Back Propagation ◽

Physical Models ◽

Layer By Layer ◽

Linear Regression Models ◽

Feed Forward Back Propagation ◽

The Impact

An experimental investigation of the surface quality of the Poly-Jet 3D printing (PJ-3DP) process is presented. PJ-3DP is an additive manufacturing process, which uses jetted photopolymer droplets, which are immediately cured with ultraviolet lamps, to build physical models, layer-by-layer. This method is fast and accurate due to the mechanism it uses for the deposition of layers as well as the 16 microns of layer thickness used. Τo characterize the surface quality of PJ-3DP printed parts, an experiment was designed and the results were analyzed to identify the impact of the deposition angle and blade mechanism motion onto the surface roughness. First, linear regression models were extracted for the prediction of surface quality parameters, such as the average surface roughness (Ra) and the total height of the profile (Rt) in the X and Y directions. Then, a Feed Forward Back Propagation Neural Network (FFBP-NN) was proposed for increasing the prediction performance of the surface roughness parameters Ra and Rt. These two models were compared with the reported ones in the literature; it was revealed that both performed better, leading to more accurate surface roughness predictions, whilst the NN model resulted in the best predictions, in particular for the Ra parameter.

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Surface Quality Assessment after Milling AZ91D Magnesium Alloy Using PCD Tool

Materials ◽

10.3390/ma13030617 ◽

2020 ◽

Vol 13 (3) ◽

pp. 617 ◽

Cited By ~ 3

Author(s):

Ireneusz Zagórski ◽

Jarosław Korpysa

Keyword(s):

Surface Roughness ◽

Magnesium Alloy ◽

High Speed ◽

Cutting Speed ◽

Cutting Parameters ◽

Depth Of Cut ◽

Machining Parameters ◽

Roughness Parameters ◽

Operational Parameters

Surface roughness is among the key indicators describing the quality of machined surfaces. Although it is an aggregate of several factors, the condition of the surface is largely determined by the type of tool and the operational parameters of machining. This study sought to examine the effect that particular machining parameters have on the quality of the surface. The investigated operation was the high-speed dry milling of a magnesium alloy with a polycrystalline diamond (PCD) cutting tool dedicated for light metal applications. Magnesium alloys have low density, and thus are commonly used in the aerospace or automotive industries. The state of the Mg surfaces was assessed using the 2D surface roughness parameters, measured on the lateral and the end face of the specimens, and the end-face 3D area roughness parameters. The description of the surfaces was complemented with the surface topography maps and the Abbott–Firestone curves of the specimens. Most 2D roughness parameters were to a limited extent affected by the changes in the cutting speed and the axial depth of cut, therefore, the results from the measurements were subjected to statistical analysis. From the data comparison, it emerged that PCD-tipped tools are resilient to changes in the cutting parameters and produce a high-quality surface finish.

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Rotary Ultrasonic Machining of Alumina Ceramic: An Experimental Investigation of Tool Path and Tool Overlapping

Applied Sciences ◽

10.3390/app10051667 ◽

2020 ◽

Vol 10 (5) ◽

pp. 1667 ◽

Cited By ~ 1

Author(s):

Basem M. A. Abdo ◽

Abdualziz El-Tamimi ◽

Emad Abouel Nasr

Keyword(s):

Surface Roughness ◽

Surface Morphology ◽

Surface Quality ◽

Tool Path ◽

Removal Rate ◽

Ultrasonic Machining ◽

Rotary Ultrasonic Machining ◽

Roughness Surface ◽

Tool Wear Mechanisms

Pocket milling has been regarded as one of the most widely used operations in machining. The surface quality of the machined pockets is an essential aspect of any engineering and medical applications. In the current study, rotary ultrasonic machining (RUM) was applied for milling micro-pockets on alumina (Al2O3) ceramic. The objective of this research was to analyze the effect of the tool overlapping parameters on the surface roughness, surface morphology and the profiles of the machined pockets. Subsequently, the effect of different tool path strategies was analyzed on the surface quality and the material removal rate (MRR) of the machined pockets. A scanning electron microscope is used for analyzing the tool wear mechanisms. The experimental results provide evidence that the surface roughness, surface morphology and the MRR have been significantly affected by the considered tool overlapping and the tool path strategies. Furthermore, among the selected tool overlapping parameters (5–25%) and the tool path strategies, the best surface roughness (Ra = 0.155 μm and Rt = 1.432 µm) of the machined pockets can be found at 20% of the tool overlapping with a mix of uni-directional and zigzag tool path strategy.

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ANALYSIS OF THE CORRELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE SIGNAL AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽

10.1142/s0218348x19500130 ◽

2019 ◽

Vol 27 (02) ◽

pp. 1950013 ◽

Cited By ~ 23

Author(s):

AHMAD THUFFAIL THASTHAKEER ◽

ALI AKHAVAN FARID ◽

CHANG TECK SENG ◽

HAMIDREZA NAMAZI

Keyword(s):

Surface Roughness ◽

Cutting Force ◽

Surface Quality ◽

Cutting Forces ◽

End Milling ◽

Complex Structure ◽

Machined Surface ◽

End Mills ◽

Machining Operations

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.

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