Investigation of Optimal Air-Driving Fluid Jet Polishing Parameters for the Surface Finish of N-BK7 Optical Glass

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Pham Huu Loc ◽  
Fang-Jung Shiou ◽  
Zong-Ru Yu ◽  
Wei-Yao Hsu
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Orthogonal Array ◽  
Optical Glass ◽  
Impact Angle ◽  
Air Pressure ◽  
Standoff Distance ◽  
Optimal Parameters ◽  
Abrasive Material ◽  
Spherical Lens

The aim of this study is to investigate optimal air-driving fluid jet polishing (FJP) parameters by using Taguchi's method to improve surface roughness of N-BK7 optical glass on a machining center. An orthogonal array and the signal-to-noise (S/N) ratio are employed to determinate the optimal polishing parameters, and analysis of variance (ANOVA) is used to identify the main parameters that affect the surface roughness of the N-BK7 optical glass. An air-driving FJP tool is newly designed and fabricated to conduct experiments. To determinate the optimal air-driving FJP parameters, six polishing parameters, namely air pressure, impact angle, standoff distance, the abrasive material, abrasive concentration, and polishing time, are selected as the control factors of experiments. Based on the Taguchi's L18 orthogonal array experimental results and the S/N ratio, the optimal parameters for the N-BK7 optical glass are found. These optimal parameters are to be as follows: an air pressure of 0.490 MPa, an impact angle of 40 deg, a standoff distance of 12 mm, the abrasive material of Al2O3, an abrasive concentration of 10 wt. %, and a polishing time of 30 min. The surface roughness of specimen is improved from Ra = 0.350 μm–0.032 μm by using the optimal air-driving FJP parameters. In addition, the determined optimal polishing parameters for the plane surface are applied to the surface finish of an N-BK7 spherical lens, and the surface roughness of the spherical lens can be improved from Ra = 0.421 μm to 0.202 μm within an area of 283.6 μm × 200 μm.

scholarly journals Application of taguchi method to investigation of optimal abrasive jet polishing parameters

2019 ◽  
Vol 17 (6) ◽  
pp. 1
Author(s):  
LOC PHAM HUU
Keyword(s):  
Taguchi Method ◽  
Analysis Of Variance ◽  
Surface Finish ◽  
Optical Glass ◽  
Impact Angle ◽  
Taguchi’S Method ◽  
Optimal Parameters ◽  
Abrasive Grain ◽  
Abrasive Jet Polishing ◽  
Pump Pressure

The surface finish of N-BK7 optical glass is improved by abrasive jet polishing (AJP) process. Taguchi’s method is employed to investigate optimal AJP parameters. The important parameters that influence the N-BK7 surface finish are determined by Analysis of variance (ANOVA). The optimal parameters are found based on Taguchi’s experimental results and signal noise ratio (S/N). These optimal parameters are: polishing time of 45 min, pump pressure of 5 kgf/cm2, standoff distance of 12 mm, abrasive grain type of Al2O3, abrasive grain concentration of 20 %, and impact angle of 40°. The surface finish (Ra) of the N-BK7 is improved significantly from 0.350 µm to 0.018 µm.

Abrasive Water Jet Polishing on Zr-Based Bulk Metallic Glass

2012 ◽  
Vol 579 ◽  
pp. 211-218 ◽  
Author(s):  
Pham Huu Loc ◽  
Fang Jung Shiou
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Impact Angle ◽  
Water Jet ◽  
Standoff Distance ◽  
Hydraulic Pressure ◽  
Abrasive Water Jet ◽  
Optimal Parameters ◽  
Abrasive Material ◽  
The Impact

This study investigates the optimal abrasive water jet polishing parameters for Zr-based bulk metallic glass (BMG) material by using the Taguchi method. An abrasive water jet polishing (AWJP) system is newly designed and mounted on a machining center. In order to determine the optimal polishing parameters for the Zr-based BMG sample, six polishing parameters, namely the hydraulic pressure, the impact angle, the standoff distance, the abrasive material, the abrasive concentration, and the polishing time, are chosen as the control factors of experiments. The optimal AWJP parameters are determined after carrying out the experiments based on the Taguchi’s L18 orthogonal array experimental results. These optimal parameters are the combination of the hydraulic pressure of 2 kg/cm2, the impact angle of 30o, the standoff distance of 15 mm, the abrasive material of SiC, the abrasive concentration of 1:5, and the polishing time of 60 minutes. The surface roughness is improved from an initial value of Ra = 0.675μm to a final value of Ra = 0.016μm by using the AWJP optimal parameters.

Influence of Abrasive Materials in Fluidised Bed Machining of AlSi10Mg Parts Made through Selective Laser Melting Technology

2019 ◽  
Vol 813 ◽  
pp. 129-134 ◽  
Author(s):  
Andrea El Hassanin ◽  
Maurizio Troiano ◽  
Alessia Teresa Silvestri ◽  
Vincenzo Contaldi ◽  
Fabio Scherillo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Selective Laser Melting ◽  
Impact Angle ◽  
Fluidised Bed ◽  
Laser Melting ◽  
Abrasive Material ◽  
Melting Technology ◽  
Post Process ◽  
The Impact ◽  
Complex Parts

Metal Additive Manufacturing technologies development is increasing in a remarkable way due to their great potential concerning the production of complex parts with tailored characteristics in terms of design, material properties, usage and applications. Among all, the most widespread technologies are the Powder Bed Fusion based technologies such as Selective Laser Melting and Electron Beam Melting. However, the high surface roughness of the as-built parts still represents one of the major limitations, making necessary the adoption of post-process finishing to match the technological requirements for most of the fields of application. In this scenario, Fluidised Bed Machining represents an emerging finishing technology that could overcome some of the limitations of the most common methods, especially in terms of feasibility for the treatment of complex parts thanks to the fluid-like mobility of the abrasive material. This work deals with the preliminary tests of the Fluidised Bed Machining of additive manufactured samples using alumina as the abrasive material, investigating the effects of a high abrasive/substrate hardness ratio condition. The experiments were carried out on small plates of AlSi10Mg alloy made through Selective Laser Melting technology, built in the vertical direction with respect to the building plate. The influence of the impact angle and treatment time were investigated under bubbling fluidization conditions. Surface morphology evaluations were carried out pre and post process by means of Confocal Microscopy and Scanning Electron Microscopy (SEM). Weight loss measurements were conducted to evaluate the material removal rates as well. Results show a small influence of the specific impact angle, a slight reduction of the surface roughness and an asymmetrical effect of treatment, acting mostly on the sintered powders forming the peaks of the as-built surface.

Development of a Small Rotary Multi-Jet Abrasive Fluid Jet Polishing Tool

2014 ◽  
Vol 625 ◽  
pp. 140-148 ◽  
Author(s):  
Assefa Asmare Tsegaw ◽  
Fang Jung Shiou
Keyword(s):  
Surface Roughness ◽  
Optical Glass ◽  
Fluid Pressure ◽  
Head Rotation ◽  
Angular Speed ◽  
Diamond Turning ◽  
Optimal Parameters ◽  
Optical Glasses ◽  
Control Factors ◽  
Polishing Tool

Most optical glasses are in recent years being manufactured by diamond turning processes which has certainly modernized the field of production of optics. Confines of diamond turning for both form and surface finish accuracy have not been reached, yet. In advent of contemporary technology, high precision finishing techniques are of great concern and the need of present industrialized-scenario. This paper presents the development of a small rotary multi-jet abrasive fluid jet polishing tool for use in polishing of optical glasses. The newly designed and manufactured tool has relative angular speed with respect to the spindle of machining centre and is capable of polishing at micro levels. The paper also investigates the optimal polishing parameters for selected, crown optical glass based on experiments conducted using Taguchi’s experimental method. According to the possible number of control factorsL18orthogonal array was used. ANOVA analysis was carried out to determine the main factors which would affect the surface roughness significantly. Consequently, a 2.5 μm size of Al2O3abrasive, 10wt% abrasive concentration, 40 rpm of polishing head rotation, 6 numbers of nozzles, 6 kg/cm2of fluid pressure, 45minuet of polishing time and 40% of step over have been found to be the optimal parameters. It was observed that about 97.22% improvements on surface roughness; Ra, from 0.360 μm to 0.010 μm has been achieved using the optimal parameters. In addition to this; rotation of polishing head, applied fluid pressure and polishing time were found to have significant effect on surface roughness improvement.

Development of a Self-Propelled Multi-Jet Polishing Tool for Ultra Precision Polishing

2014 ◽  
Vol 939 ◽  
pp. 481-490
Author(s):  
Assefa Asmare Tsegaw ◽  
Fang Jung Shiou
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Turbine Blades ◽  
Angular Speed ◽  
Optimal Parameters ◽  
Optical Glasses ◽  
High Kinetic Energy ◽  
Ultra Precision ◽  
Head Pressure ◽  
Polishing Tool

As the needs of optical glasses are on the rise, the precision on shape, form, surface qualities and the scaling down of sizes are rising, too. The standards and surface finish of reference mirrors used in measuring appliances are crucial; hence, enhancement of the surface finish is indispensable in manufacturing industries. This paper proposes a self-propelled multi jet polishing technique for ultra precision polishing process in which bladelessTesla turbinewas used as a prime mover. The turbine is characterized by high swirling velocity at the outlet; therefore, high kinetic energy in the course of away from the turbine was used as polishing energy. Simulation of the flow of the field of turbine blades using computational fluid dynamics software (CFD) has also been presented. With a newly designed and manufactured polishing tool, this paper investigates the optimal polishing parameters for surface roughness improvement of crown optical glasses using Taguchis experimental approach; signal-to-nose (S/N) ratio and ANOVA analysis was also carried out to determine the effect of main factors on the surface roughness. Consequently, a 2.5μm size of Al2O3abrasive, 10wt% abrasive concentration, 80rpm of polishing head, 6 numbers of nozzles, 6 kg/cm2of pressure, and 45min. of polishing time have been found to be the optimal parameters. It was observed that about 94.44% improvements on surface roughness; Ra, from 0.360μm to 0.020μm has been achieved using the optimal parameters. In addition to this; angular speed of polishing head, pressure and polishing time were found to have significant effect on surface roughness improvement.

Effects of Insert Nose Radius and Processing Cutting Parameter on the Surface Roughness of Aisi 316 Stainless Steel

2010 ◽  
Vol 447-448 ◽  
pp. 51-54
Author(s):  
Mohd Fazuri Abdullah ◽  
Muhammad Ilman Hakimi Chua Abdullah ◽  
Abu Bakar Sulong ◽  
Jaharah A. Ghani
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Finish ◽  
Feed Rate ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Nose Radius ◽  
Aisi 316

The effects of different cutting parameters, insert nose radius, cutting speed and feed rates on the surface quality of the stainless steel to be use in medical application. Stainless steel AISI 316 had been machined with three different nose radiuses (0.4 mm 0.8 mm, and 1.2mm), three different cutting speeds (100, 130, 170 m/min) and feed rates (0.1, 0.125, 0.16 mm/rev) while depth of cut keep constant at (0.4 mm). It is seen that the insert nose radius, feed rates, and cutting speed have different effect on the surface roughness. The minimum average surface roughness (0.225µm) has been measured using the nose radius insert (1.2 mm) at lowest feed rate (0.1 mm/rev). The highest surface roughness (1.838µm) has been measured with nose radius insert (0.4 mm) at highest feed rate (0.16 mm/rev). The analysis of ANOVA showed the cutting speed is not dominant in processing for the fine surface finish compared with feed rate and nose radius. Conclusion, surface roughness is decreasing with decreasing of the feed rate. High nose radius produce better surface finish than small nose radius because of the maximum uncut chip thickness decreases with increase of nose radius.

scholarly journals An Investigation of the High-Frequency Ultrasonic Vibration-Assisted Cutting of Steel Optical Moulds

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 460
Author(s):  
Canbin Zhang ◽  
Chifai Cheung ◽  
Benjamin Bulla ◽  
Chenyang Zhao
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Vibration ◽  
High Frequency ◽  
Optical Glass ◽  
Contact Point ◽  
Cutting Speed ◽  
Optical Quality ◽  
Machining Parameters ◽  
Nose Radius ◽  
Cutting Geometry

Ultrasonic vibration-assisted cutting (UVAC) has been regarded as a promising technology to machine difficult-to-machine materials such as tungsten carbide, optical glass, and hardened steel in order to achieve superfinished surfaces. To increase vibration stability to achieve optical surface quality of a workpiece, a high-frequency ultrasonic vibration-assisted cutting system with a vibration frequency of about 104 kHz is used to machine spherical optical steel moulds. A series of experiments are conducted to investigate the effect of machining parameters on the surface roughness of the workpiece including nominal cutting speed, feed rate, tool nose radius, vibration amplitude, and cutting geometry. This research takes into account the effects of the constantly changing contact point on the tool edge with the workpiece induced by the cutting geometry when machining a spherical steel mould. The surface morphology and surface roughness at different regions on the machined mould, with slope degrees (SDs) of 0°, 5°, 10°, and 15°, were measured and analysed. The experimental results show that the arithmetic roughness Sa of the workpiece increases gradually with increasing slope degree. By using optimised cutting parameters, a constant surface roughness Sa of 3 nm to 4 nm at different slope degrees was achieved by the applied high-frequency UVAC technique. This study provides guidance for ultra-precision machining of steel moulds with great variation in slope degree in the pursuit of optical quality on the whole surface.

Roller Burnishing Method with Active Rotation Tool - Better Surface Finish than Conventional Roller Burnishing

2017 ◽  
Vol 749 ◽  
pp. 9-14 ◽  
Author(s):  
Masato Okada ◽  
Yuki Miyagoshi ◽  
Masaaki Otsu
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Surface Finish ◽  
Circumferential Direction ◽  
Theoretical Equation ◽  
Sliding Angle ◽  
Roller Burnishing ◽  
Sliding Direction ◽  
Cylindrical Workpiece ◽  
Sectional Profile

This paper proposes a roller burnishing method that controls the sliding direction of the burnishing tool on the surface of cylindrical workpiece. In this study, the sliding direction was set by inclining the axis of the burnishing tool with respect to the axis of the workpiece and by actively rotating the roller of the burnishing tool. The workpiece was a cylindrical aluminum alloy bar, which was rotated in a bench lathe. The burnished surfaces at several sliding angles between 15º and 90º were evaluated. The sliding direction, which is set according to a theoretical equation, was experimentally obtained for every sliding angle in the range of 15-90º with respect to the circumferential direction of the workpiece. The sectional profile was flattened and surface roughness was decreased with increasing sliding angle. As a result, the burnished surfaces obtained in this work were superior to those obtained in an earlier study by the authors, in which the burnishing tool was not actively rotated.

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