Finishing Performance of the Abrasive Flow Machining in Complex Holes by Using Helical Cores

2020 ◽  
Vol 831 ◽  
pp. 52-56
Author(s):  
A. Cheng Wang ◽  
Ken Chuan Cheng ◽  
Kuan Yu Chen ◽  
Yan Cherng Lin
Keyword(s):  
Surface Roughness ◽  
Smooth Surfaces ◽  
Narrow Gap ◽  
Abrasive Flow Machining ◽  
The Core ◽  
Fine Surface ◽  
Spiral Grooves

Since abrasive gels with single direction motion are very difficulty to achieve the smooth surfaces in the complex holes finishing during abrasive flow machining (AFM), therefore, the helical cores were proposed here to create the multiple motions of abrasive gels to get the even surface of the complex holes in AFM. The results showed that helical core with 5 spiral grooves and narrow gap between the core tip and the hole could obtain the even surface and fine surface roughness after AMF.

Adhesion and Pull-Off Forces for Polysilicon MEMS Surfaces Using the Sub-Boundary Lubrication Model

2002 ◽  
Vol 125 (1) ◽  
pp. 193-199 ◽  
Author(s):  
Allison Y. Suh ◽  
Andreas A. Polycarpou
Keyword(s):  
Surface Roughness ◽  
Boundary Lubrication ◽  
Intermolecular Forces ◽  
Contact Forces ◽  
Root Mean Square Roughness ◽  
Magnetic Storage ◽  
Smooth Surfaces ◽  
Adhesion Forces ◽  
Disk Interface ◽  
Adhesion Model

Miniature devices including MEMS and the head disk interface in magnetic storage often include very smooth surfaces, typically having root-mean-square roughness, σ of the order of 10 nm or less. When such smooth surfaces contact, or come into proximity of each other, either in dry or wet environments, then strong intermolecular (adhesive) forces may arise. Such strong intermolecular forces may result in unacceptable and possibly catastrophic adhesion, stiction, friction and wear. In the present paper, a model termed sub-boundary lubrication (SBL) adhesion model is used to calculate the adhesion forces, and an elastic-plastic model is used to calculate the contact forces at typical MEMS interfaces. Several levels of surface roughness are investigated representing polished and as-deposited polysilicon films that are typically found in MEMS. The SBL adhesion model reveals the significance of the surface roughness on the adhesion and pull-off forces as the surfaces become smoother. The validity of using the SBL adhesion model to estimate the pull-off forces in miniature systems is further supported by direct comparison with experimental pull-off force measurements performed on silicon and gold interfaces. Finally, the significance of the interfacial forces as relate to the reliability of MEMS interfaces is discussed.

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

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.

Development of the improved Preston equation for abrasive flow machining of aerofoil structures and components

2018 ◽  
Vol 233 (9) ◽  
pp. 1397-1404 ◽  
Author(s):  
Kai Cheng ◽  
Yizhi Shao ◽  
Mitul Jadva ◽  
Rodrigo Bodenhorst
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Machining Process ◽  
Dynamics Simulation ◽  
Abrasive Machining ◽  
Abrasive Particles ◽  
Abrasive Flow Machining ◽  
Flow Features ◽  
The Media ◽  
Experimental Trials

The paper presents an improved Preston equation, which aims to be part of the industrial application to abrasive flow machining. The equation will aid the engineers to optimise the process for desired surface roughness and edge tolerance characteristics on complex geometries in an intuitive and scientific manner. The methodology presented to derive the equation underpins the fundamental cutting mechanics of abrasive machining or polishing assuming all abrasive particles within the media are spherical as manufacturers defined. Further to derivation, full four factorial experimental trials and computational fluid dynamics simulation are implemented to generate the flow features of media on coupon to evaluate and validate the equation for its competency and accuracy on prediction of material removal. The modified Preston equation can significantly contribute to optimise the abrasive flow machining process, and will advantage the integrated machine design to predict better virtual surface roughness and material removal rates.

Study on the improvement of the surface integrity and efficiency of electrical-discharge-machined TC4 titanium alloy via abrasive flow machining

2020 ◽  
pp. 095440542097109
Author(s):  
Ze Yu ◽  
Dunwen Zuo ◽  
Yuli Sun ◽  
Guohua Li ◽  
Xuemei Chen ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Surface Quality ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Small Hole ◽  
Machining Process ◽  
Machining Efficiency ◽  
Abrasive Flow Machining ◽  
Tc4 Titanium Alloy

To simultaneously optimize the surface quality and machining efficiency of the electrical discharge machining (EDM) processes used to produce titanium alloy quadrilateral group small hole parts, a combined “EDM + AFM” machining technology is proposed in this paper as an efficient and high-quality machining approach. In the proposed method, TC4 titanium alloy is first machined using the EDM process with graphite electrodes and the abrasive flow machining (AFM) process is then used to finish the machined surface. The effects of various electrical parameters on EDM-derived surface quality and improvements in EDM-derived quality under the application of AFM were assessed and, using the final surface roughness as a constraint condition, the effects of various combinations of EDM and “EDM + AFM” on efficiency were studied. The results revealed that the thickness and surface roughness of the superficial recast layer of the TC4 titanium alloy increase with both current and pulse width; in particular, increasing these parameters can increase the surface roughness by two to three grades. Following AFM, the alloy has a more uniform hardness distribution and the surface stress state changes from tensile to compressive stress, indicating that the combined “EDM + AFM” machining scheme can significantly enhance the surface quality of EDM-produced titanium alloy quadrilateral small group holes. The combined scheme achieves a balancing point beyond which increasing the roughness or the number of machining holes enhances either the machining efficiency or the machining surface quality. In the case of typical titanium alloy quadrilateral group small hole parts, the combined machining process can improve the finishing efficiency and total machining efficiency by 71.2% and 25.36%, respectively.

scholarly journals Experimental Study on the Effects of Coolants on Surface Quality and Mechanical Properties of Micromilled Thin-Walled Elgiloy

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1497 ◽  
Author(s):  
Da Qu ◽  
Peng Zhang ◽  
Jiadai Xue ◽  
Yun Fan ◽  
Zuhui Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Surface Quality ◽  
Lower Surface ◽  
Work Piece ◽  
Dry Machining ◽  
Core Component ◽  
The Core ◽  
Thin Walled ◽  
The One

In this study, minimum quantity coolant/lubrication (MQCL) is found to have significant impact on the surface quality and mechanical properties of the micromilled thin-walled work piece that is the core component of an aeroaccelerometer. Three kinds of coolants were used in the micromilling process to analyze their effects on surface quality and mechanical properties of the component. The experiment results show that an appropriate dynamic viscosity of coolant helps to improve surface roughness. The high evaporation rate of the coolants can enhance the cooling performance. Comparing with the dry machining case, MQCL has better performance on improving tool wear, surface quality, and mechanical properties of the micromilled work piece. It yielded up to 1.4–10.4% lower surface roughness compared with the dry machining case in this experiment. The machined work piece with the best mechanical properties and the one with the worst mechanical properties appeared in the ethyl alcohol and the dry machining case, respectively. The reasons for deteriorating surface quality and mechanical properties in dry machining cases are also analyzed. For improving the micromilling process, the penetration and cooling effect of the coolants are more important. This paper gives references to obtain better service performance of the component by improving the micromilling process.

scholarly journals Enhancement of surface roughness for brittle material during rotary ultrasonic machining

2018 ◽  
Vol 249 ◽  
pp. 01006 ◽  
Author(s):  
Ankit Sharma ◽  
Atul Babbar ◽  
Vivek Jain ◽  
Dheeraj Gupta
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Vibration Amplitude ◽  
Research Study ◽  
Float Glass ◽  
Spindle Speed ◽  
Ultrasonic Machining ◽  
Rotary Ultrasonic Machining ◽  
Hole Quality ◽  
The Core

Surface roughness is the key aspect which could increase the application of float glass by enhancing the machined hole quality. Glass is extensively used in microfluidic devices, bio-medical parts and biosensors. The core objective of the research study is to optimize the best parametric combination to achieve the least amount of surface roughness. The three major parameters which are used for designed experimental study are spindle speed, ultrasonic amplitude and feed rate. The least value of surface roughness is noticed at spindle speed (5000 rpm), vibration amplitude (20 μ m) and feed rate (6 mm/min) which be adopted for increasing its functional application. Consequently, after optimizing the parameters, least value of surface roughness at hole internal region is revealed as 1.09 μm.

Experimental Investigation for the Multi-objective Optimization of Machining Parameters on AISI D2 Steel Using Particle Swarm Optimization Coupled with Artificial Neural Network

2020 ◽  
Vol 19 (03) ◽  
pp. 589-606 ◽  
Author(s):  
Vipin Gopan ◽  
K. Leo Dev Wins ◽  
Gecil Evangeline ◽  
Arun Surendran
Keyword(s):  
Neural Network ◽  
Surface Roughness ◽  
Artificial Neural Network ◽  
Cutting Force ◽  
Surface Finish ◽  
Fitness Function ◽  
Machining Parameters ◽  
Swarm Optimization ◽  
Fine Surface ◽  
Aisi D2

High Carbon High Chromium (or AISI D2) Steels, owing to the fine surface finish they produce upon grinding, find lot of applications in die casting. Machining parameters affect the surface finish significantly during the grinding operation. In this context, this work puts an effort to arrive at the optimum machining parameters relating to fine surface finish with minimum cutting force. The material removal caused by the abrasive grinding wheel makes the process a very complex and nonlinear machining operation. In many situations, traditional optimization techniques fail to provide realistic optimum conditions because of the associated complexity. In order to overcome this issue, particle swarm optimization (PSO) coupled with artificial neural network (ANN) is applied in this research work for parameter optimization with the objective of achieving minimum surface roughness and cutting force. The machining parameters selected for the investigation were table speed, cross feed and depth of cut and the responses were surface roughness and cutting force. ANNs, inspired from biological neural networks, are well capable of providing patterns, which are too complex in behavior. The ANN model developed was used as the fitness function for PSO to complete the optimization. Optimization was also carried out using conventional response surface methodology-genetic algorithm (RSM-GA) approach in which regression equation developed with RSM was considered as the fitness function for GA. Confirmatory experiments were conducted and the comparison showed that PSO coupled with ANN is a reliable tool for complex optimization problems.

Analysis of the surface roughness obtained by the abrasive flow machining process using an abrasive paste with oiticica oil

2020 ◽  
Vol 106 (11-12) ◽  
pp. 5061-5070 ◽  
Author(s):  
Marcelo Rodrigo Munhoz ◽  
Larissa Galante Dias ◽  
Ricardo Breganon ◽  
Fernando Sabino Fonteque Ribeiro ◽  
Janaina Fracaro de Souza Gonçalves ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Machining Process ◽  
Abrasive Flow Machining
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