scholarly journals A Proposed Scan Strategy Used on SLM Inner Structure Part

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 937 ◽  
Author(s):  
Jitai Han ◽  
Meiping Wu ◽  
Weipeng Duan
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Laser Energy ◽  
Side Surface ◽  
Test Results ◽  
New Strategy ◽  
Optimal Surface ◽  
The Relationship ◽  
Main Factor

A model with an inner structure was designed to study the relationship between the surface quality of the inner structure and the scan strategy in this study. The test results showed that the precision of the inner structure was highly affected by the scan strategy, and the specimens printed using different strategies showed different performances on the surface quality of the inner structure. The specimen printed using the square-framed scan strategy had a lower flatness value on the positive face of the inner structure compared to that of the other two specimens printed using Z-shape scan strategies, while the specimen printed using the Z-shape scan strategy (along the inner structure) had a relative optimal surface roughness on the side surface of the inner structure in all three specimens. The bending deformation caused by the scan strategies was considered to be the main factor affecting the flatness on the positive surface, while laser energy fluctuation showed a significant impact on side surface roughness. Combined with the experimental data, a new scan strategy was proposed; we found that the specimen printed using this new strategy improved positive surface flatness and side surface roughness.

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

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.

scholarly journals Pseudo-random Path Generation Algorithms and Strategies for the Surface Quality Improvement of Optical Aspherical Components

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1216
Author(s):  
Jun Zha ◽  
Hangcheng Zhang ◽  
Yipeng Li ◽  
Yaolong Chen
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Path Generation ◽  
Optical Components ◽  
Validation Experiment ◽  
Polishing Path ◽  
Computer Controlled Optical Surfacing ◽  
The Relationship ◽  
Convolution Effect

This study proposes two path generation algorithms to diminish the superposition of the convolution effect on the polishing path in computer-controlled optical surfacing. According to the polishing of aluminum-alloy based hyperboloid optical components, different proportions of polishing agents were blended. Then, the surface roughness of the optical components were determined through a validation experiment of the algorithms. Furthermore, the relationship between surface roughness and the polishing agent concentration, and the compensation strategies for surface roughness were analyzed. The results show that the two algorithms effectively compensated for surface waviness. The findings support the strategies for improving the surface quality of optical components with aspherical surfaces.

Dry WEDM in Improving HS-WEDMed Surface Quality

2008 ◽  
Vol 392-394 ◽  
pp. 624-628 ◽  
Author(s):  
Tong Wang ◽  
Yu Mei Lu ◽  
Shuang Shuang Hao ◽  
Shu Qiang Xie ◽  
Xiao Cun Xu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Material Removal ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Dry Wedm ◽  
Finish Cut ◽  
The Relationship

This paper studies the surface quality of mould steel with high-speed wire electrical discharge machining (WEDM) method, which is conducted in gas to improve the accuracy of finish cut, and compares the surface quality in atmosphere and in emulsion dielectric. Experiment results showed that WEDM in atmosphere offers advantages such as better surface roughness and higher material removal rate. The relationship about winding speed and worktable feed on WEDMed surface quality in semi-finishing cut and finishing cut had been obtained. Morover, a new attemption was successful in applying dry WEDM in multiple cut to improve surface roughness.

Modeling for Prediction of Surface Roughness and Experimental Research in Ultra-Precision Flycutting Machining

2018 ◽  
Author(s):  
Jiasheng Li ◽  
Yang Jiao ◽  
Pinkuan Liu
Keyword(s):  
Surface Roughness ◽  
Prediction Model ◽  
Surface Quality ◽  
Cutting Parameters ◽  
Machining Parameters ◽  
Ultra Precision ◽  
Set Up ◽  
Validation Tests ◽  
The Relationship

To improve the surface quality of the copper and reduce the diamond tool wear, a prediction model is established experimentally for the relationship between surface roughness and machining parameters. Based on the processing principle of flycutting machining, the prediction model for surface roughness is set up by response surface methodology. Then, a machining experiment for the copper is conducted under different cutting parameters designed by Taguchi method and the surface roughness is tested by 4D technology dynamic laser interferometer. After that, the prediction model is obtained by analyzing the experimental data, and the accuracy of the model is verified by analysis of variance (ANOVA), R2 value and residual analysis. Furthermore, the effect of cutting parameters upon the surface roughness is analyzed. Finally, validation tests are conducted to verify the model. Experimental results demonstrate that the prediction model is adequate at 95% confidence level. The output of prediction model helps to select cutting parameters to reduce surface roughness which ensures surface quality in ultra-precision fly cutting machining.

A study on the surface quality of the 3D printed parts caused by the scanning strategy

2019 ◽  
Vol 25 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Jitai Han ◽  
Yanan Ge ◽  
Yuxin Mao ◽  
Meiping Wu
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Scanning Strategy ◽  
Clear Trend ◽  
Content Type ◽  
3D Printed ◽  
Side Face ◽  
Zigzag Shape ◽  
The Relationship

Purpose The purpose of this paper is to mainly focus on the relationship between the scanning strategy and surface quality. Surface quality, including surface roughness and flatness, is important for printed parts. So this paper optimizes the surface quality by changing the scanning strategy. Design/methodology/approach This paper is based on the phenomenon after the printed parts. A clear trend can be seen that the surface roughness on the side face shows a clear zigzag shape, so an optimized scanning strategy is used. Surface roughness in measured in macrostructure first by Mitutoyo and the flatness is measured by Hexagon Metrocogy. After that, microstructure on the side face is seen by RTEC to explain this phenomenon. Findings The surface quality on the side face shows a significant optimize by changing the scanning strategy. The surface quality on the positive face has some optimization to some degree. Originality/value This paper determines the relationship between the surface roughness on the side face and the scanning strategy. Few studies focus on the surface roughness, especially on the side face. Some studies try to optimize the surface roughness on the positive face. However, researchers always neglect the surface roughness on the side face. 2. This paper measures not only the surface roughness, but also the flatness. Surface roughness has a significant impact on the surface quality. However, it still has some limitations. Flatness is also measured to make this paper more representative. 3. This paper explains why scanning strategy can affect the surface quality. These images explain the research better and not just at the theoretical level.

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

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.

SLS Process Parameter Optimization to Improve Surface Quality and Accuracy of Polyamide Parts

2021 ◽  
Vol 11 (4) ◽  
pp. 57-74
Author(s):  
Sunil Dutt Baloni ◽  
Somesh K. Sharma ◽  
Jagroop Singh ◽  
Sushant Negi
Keyword(s):  
Surface Roughness ◽  
Layer Thickness ◽  
Surface Quality ◽  
Manufacturing Industry ◽  
Selective Laser Sintering ◽  
Anova Analysis ◽  
Part Quality ◽  
Bed Temperature ◽  
Optimal Surface ◽  
Part Orientation

The contribution of selective laser sintering (SLS) technique in the 4.0 manufacturing industry is undisputedly significant. SLS part quality exhibits high dependence on SLS process parameters and is a major challenge. Therefore, this research aims to investigate the effect of input parameters (i.e., part orientation, bed temperature, and layer thickness) on the surface roughness and accuracy of laser-sintered polyamide specimens. Response surface methodology (RSM) and ANOVA analysis aided the testing and evaluation. Optimal working conditions for minimum shrinkage were 0.17 mm layer thickness, 177.89°C part bed temperature, and part orientation at 88.91 degrees. The surface quality deteriorated with the increment in part bed temperature and layer thickness, and it shows an inverse trend (or improves) with the part orientation in the prescribed range. The optimal surface roughness was at a layer thickness of 0.11 mm, bed temperature at 174.55°C, and part orientation at 86.5 degrees.

scholarly journals Study of the effect of institutional ownership on accounting quality and cost of capital

2021 ◽  
Vol 9 (SPE2) ◽  
Author(s):  
Reza Fallah
Keyword(s):  
Significant Relationship ◽  
Cost Of Capital ◽  
Accounting Information ◽  
Institutional Ownership ◽  
Test Results ◽  
Accounting Quality ◽  
Quality Of Accounting Information ◽  
The Relationship

The test results of the research hypotheses showed that there is a significant relationship between institutional ownership and quality of accounting information and cost of capital debt, but institutional ownership has not been able to moderate the relationship between quality of accounting information and cost of capital debt.

scholarly journals Analysis of the surface quality of polycaprolactam 3D prints enriched with carbon and glass fiber

2021 ◽  
Vol 338 ◽  
pp. 01005
Author(s):  
Damian Dzienniak ◽  
Jan Pawlik
Keyword(s):  
Glass Fiber ◽  
Surface Quality ◽  
Fused Deposition Modeling ◽  
Polyamide 6 ◽  
Fiber Glass ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
The Impact ◽  
The Relationship

Additive manufacturing has been gaining popularity and availability year by year, which has resulted in its dynamic development. The most common 3D printing method as of today, FDM (Fused Deposition Modeling), owing to its peculiarity, does not always guarantee producing objects with low surface roughness. The authors of the present article have taken on the analysis of the impact of FDM printing on the roughness of the filament thus processed. They also investigate the relationship between the roughness of the unprocessed filament (made of polycaprolactam, that is, polyamide 6 or PA6) with admixtures of other materials (carbon fiber, glass fiber) and the surface quality of the manufactured object. The main subject of the analysis is the side surfaces of 3D prints, as it is their quality that is usually directly dependent on many factors connected with the process of the laying of the consecutive layers. The authors check step by step whether there exists a pronounced relationship between the roughness of the original filament material and the roughness of the obtained surface.

Study on Surface Roughness Based on Dynamic Minimum Thickness of Cut

2011 ◽  
Vol 88-89 ◽  
pp. 34-37
Author(s):  
Kuai Ji Cai
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Atomic Force Microscope ◽  
Surface Quality ◽  
Experimental Verification ◽  
Cutting Parameters ◽  
Minimum Thickness ◽  
Atomic Force ◽  
Relationship Of ◽  
The Relationship

The relationship of the friction coefficient and the MTC were discussed, and the MTC and its effects on surface roughness were a theoretical analysised and experimental verification by AFM (atomic force microscope). The results show that the theoretical MTC tends to be minimal value then before the adhering effect to reach remarkable. Appropriate adjustments cutting parameters, the cutting process can always micro-cutting phase to reach the steady-thin chip, and no plowing phenomenon. So the surface residues highly were reduced and higher surface quality was achieved.

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