scholarly journals Ball Burnishing of Mg Alloy Using a Newly Developed Burnishing Tool with On-Machine Force Control

2019 ◽  
Vol 13 (5) ◽  
pp. 619-630 ◽  
Author(s):  
Chenyao Cao ◽  
Jiang Zhu ◽  
Tomohisa Tanaka ◽  
Fang-Jung Shiou ◽  
Shunichi Sawada ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Surface Properties ◽  
Cnc Machining ◽  
Surface Finishing ◽  
Surface Plastic ◽  
Ball Burnishing ◽  
Factors Affecting ◽  
Average Grain Size ◽  
Burnishing Process

Burnishing is a surface finishing process, in which a very smooth surface finish is obtained by pressing a ball or roller against a machined workpiece. Additionally, owing to the surface plastic deformation caused by the movement of the hardened ball or roller, other surface properties such as hardness, fatigue life, and wear resistance can be improved. Burnishing force is one of the most important factors affecting the surface modification quality. However, methods for precisely monitoring and controlling the burnishing force are rarely investigated. In this research, a novel ball burnishing tool embedded with a load-cell and air-servo system was developed and fabricated for application to a CNC machining center. Using a specially designed control software, the burnishing force in the burnishing process was monitored in real time and controlled constantly and precisely by a force feedback system. Magnesium alloy AZ31 specimens were used to evaluate the performance of the developed system. The experiments were divided into two parts. In the first part, the effects of the processing parameters on the surface roughness were investigated. The results indicated that the surface roughness could be improved from Ra= 1.95 μm to Ra= 0.26 μm. In the second part, the effects of the burnishing parameters on the surface properties were investigated by conducting experiments using Taguchi’s orthogonal array. The results suggested that the burnishing force was the most significant factors affecting the surface hardness and grain size. The Vickers hardness could be increased from HV62 to HV149. The average grain size was reduced after the burnishing process, and a work-hardening layer thickness of 0.75 mm was achieved. X-ray diffraction results indicated that the crystal orientation was modified after burnishing, and the maximum measured compressed residual stress was 186.3 MPa in the tool feed direction and 87.8 MPa in the step over direction.

Ultra Precision Surface Finishing Processes

2019 ◽  
Vol 13 (2) ◽  
pp. 174-184 ◽  
Author(s):  
Fang-Jung Shiou ◽  
Assefa Asmare Tsegaw ◽  
◽  
Keyword(s):  
Surface Roughness ◽  
Optical Glass ◽  
Load Cell ◽  
Cnc Machining ◽  
Machining Process ◽  
Surface Finishing ◽  
Cnc Machine ◽  
Ball Burnishing ◽  
Finishing Processes ◽  
Polishing Tool

Surfaces of different complex shapes are aspirated part of many scientific measuring devices, medical, astronomical, and other precision activity utilizations. Components at miniaturized level should meet required surface roughness for the intended applications. Surface finishing of freeform and miniaturized components are always difficult and need to look for a new way out. In this study, an attempt was made to improve surfaces roughness of selected, most frequently used, engineering materials using different innovative processes, which can be integrated with CNC machine centers. An advanced automated surface finishing tools such as ball burnishing embedded with load cell, vibration assisted polishing, and self-propelled abrasive multi-jet polishing tools are proposed. Ball burnishing is advantageous for pre-machining process of ball polishing. Using the polishing device embedded with load cell, the constant force polishing is achieved. To reduce the volumetric wear of a polishing ball, vibration assisted polishing device is also integrated. Moreover, self-propelled abrasive multi-jet polishing tool, which achieves 93.33% improvement of surface roughness for lapped optical glass of BK7 has been subjugated from Ra 0.300 μm to 0.020 μm. These tools can be miniaturized and applicable in small micro CNC machining centers.

Surface Finishing of Plastic Injection Mold Steel with Ball Burnishing and Spherical Polishing Processes on a Machining Center

2006 ◽  
Vol 505-507 ◽  
pp. 799-804 ◽  
Author(s):  
Fang Jung Shiou ◽  
Ju Te Chiu
Keyword(s):  
Surface Roughness ◽  
Surface Finishing ◽  
Surface Plastic ◽  
Injection Mold ◽  
Ball Burnishing ◽  
Depth Of Penetration ◽  
Machining Center ◽  
Orthogonal Array Method ◽  
Plastic Injection ◽  
Dominant Influence

This study investigates the possible ball burnishing and spherical polishing surface finish process of a freeform surface plastic injection mold on a machining center. The optimal plane polishing parameters were determined by utilizing the Taguchi’s orthogonal array method for plastic injection molding steel PDS5. Five polishing parameters, namely the speed of the polishing ball, abrasive material, feed, stepover distance and the depth of penetration were selected as the experimental factors of Taguchi’s Design of Experiment to determine the optimal plane polishing parameters, which have the dominant influence on surface roughness. The optimal plane polishing parameters have been determined after conducting the experiments of the Taguchi’s L18 orthogonal table. The optimal plane polishing parameters for the plastic injection mold steel PDS5 were the combination of the polishing speed 18,000 rpm, the abrasives of aluminum oxide (Al2O3) with grid no. 5000, the feed of 100 mm/min., stepover distance of 60μ m, and the depth of penetration of 240 μ m. The surface roughness Ra of the specimen can be improved from about 1.125μ m to 0.067μ m using the optimal ball burnishing parameters for plane burnishing. The surface roughness Ra of the burnished specimen can be further improved from about 0.067μ m to 0.023μ m using the optimal polishing parameters.

scholarly journals Study the influence of a new ball burnishing technique on the surface roughness of AISI 1018 low carbon steel

2015 ◽  
Vol 4 (1) ◽  
pp. 227
Author(s):  
Abd Alkader Ibrahim ◽  
Tamer Khalil ◽  
Tarik Tawfeek
Keyword(s):  
Surface Roughness ◽  
Carbon Steel ◽  
High Pressures ◽  
Cold Work ◽  
Low Carbon Steel ◽  
Surface Finishing ◽  
Feed Speed ◽  
Low Carbon ◽  
Ball Burnishing ◽  
Burnishing Process

Hard roller burnishing with a ball tool is a surface-finishing where a free-rotating tool rolls over the machined surface under high pressures and flattens the surface roughness peaks by cold work. In the present work, a new burnishing technique has been applied which enables both single and double ball burnishing process in site after turning without releasing the specimen. Sets of experiments are conducted to investigate the influence of burnishing force, feed, speed and number of tool passes on surface roughness of AISI 1018 Low Carbon Steel specimens. Burnishing results showed significant effectiveness of the new burnishing technique in the process. The results revealed that minimum surface roughness are obtained by applying the double ball burnishing process on AISI 1018 Low Carbon Steel specimens. Improvement in surface finish can be achieved in both single and double ball burnishing by increasing the number of burnishing tool passes. The results are presented in this paper.

Grain Structure and Surface Roughness of Four Commercial NiTi Orthodontic Archwires

2017 ◽  
Vol 266 ◽  
pp. 257-263
Author(s):  
Wassana Wichai ◽  
Rutchadakorn Isarapatanapong ◽  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Optical Microscope ◽  
Grain Structure ◽  
Wire Surface ◽  
Average Grain Size ◽  
Electron Mode ◽  
The Mean ◽  
The Wire ◽  
Orthodontic Archwires

This study investigated four commercially available NiTi orthodontic archwires from different manufactures for their grain structure and surface roughness.Four commercially available pre-formed NiTi orthodontic archwire (Ormco, Sentalloy, Highland and NIC) with diameter 0.016 x 0.022 inch2 were tested. The wire samples were polished and etched to evaluate the morphology and structure of wire surface. Each NiTi archwire was investigated under a reflected light microscope of an Optical Microscope to analyze its grain structure and size, in longitudinal surfaces. The surfaces of wire were qualitatively examined in the secondary electron mode at common magnification (500X). The surface roughness was also evaluated by a surface roughness tester. The descriptive statistic was evaluated the mean and standard deviation of surface roughness and Medcale T-Test was to test the mean difference of the surface roughness in each brands. This study showed an average grain size of 2-8 μm for each NiTi archwire. The wire surface of Ormco and Highland showed straiations along the longitudinal axes, however Sentalloy and NIC showed small pores on the wire surface. The surface roughness was 0.09 μm for Highland, 0.25 μm for Sentalloy, 0.28 μm for Ormco and 0.46 μm for NIC archwire. The Highland was smoothest and NIC was the roughest. There were in significant (p < 0.05) difference of surface roughness of each brands. The results showed that the four manufactures NiTi archwires were different in grain size, wire surface and surface roughness. During clinical application, these archwires may exhibit different mechanical properties, such as strength, hardness, ductity, and friction because of their microstructure.

Analysis and Prediction of Surface Integrity in Machining: A Review

2014 ◽  
Vol 610 ◽  
pp. 1002-1020 ◽  
Author(s):  
Yuan Gao ◽  
Xin Huang ◽  
Ming Jie Lin ◽  
Zheng Guo Wang ◽  
Rong Lei Sun
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Residual Stresses ◽  
Surface Integrity ◽  
Material Properties ◽  
Cutting Parameters ◽  
Mechanical Parameters ◽  
Factors Affecting ◽  
Grain Size And Shape

Surface integrity is widely used for evaluating the quality of machined components. It has a set of various parameters which can be grouped as: (a) topography parameters such as surface roughness, textures and waviness (b) mechanical parameters such as residual stresses and hardness, and (c) metallurgical state such as microstructure, phase transformation, grain size and shape, inclusions etc. Surface roughness and residual stresses are among the most significant parameters of surface integrity, so that it is worth investigating them particularly. Many factors affect the surface integrity of machined components, including cutting parameters, tool parameters, material properties and vibrations. We can make prediction and optimization for surface integrity by taking advantage of these factors. This paper reviews previous studies and gives a comprehensive summary of surface integrity in the following order: introduction of surface integrity, main parameters of surface integrity, factors affecting surface integrity, prediction and optimization for surface integrity.

scholarly journals Physiochemical effect on the microgroove microstructure in microcutting of pure copper

2021 ◽  
Author(s):  
Jiayi Zhang
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Cutting Force ◽  
Thrust Force ◽  
Pure Copper ◽  
Geometrically Necessary Dislocation ◽  
Free Sample ◽  
Induced Stress ◽  
Average Grain Size ◽  
Grain Orientations

Abstract Physiochemical effect on the machining of pure copper is studied via microstructure characterization on the cross-sectioned microgroove. An obvious decreased cutting force and thrust force were obtained with the application of surfactant. The surface roughness of microgroove with physiochemical effect is 12 nm, and that without physiochemical effect is 17 nm. The average grain size of the medium-affected sample is 67.9 µm within the microgroove zone, and that of the medium-free sample is 48.3 µm within the microgroove zone, moreover, the grain size of medium-free microgroove near the microgroove surface is larger than that far away from the microgroove surface. Additionally, the grain orientations of medium-affected cross-sectioned surface present anisotropy, while that of medium-free cross-sectioned surface are towards {101} direction. Based on the calculation and analysis of geometrically necessary dislocation, it can be inferred that the induced stress and temperature in the sample with physiochemical effect are higher than that without physiochemical effect, which can provide enough driving energy for recrystallization.

Structural, morphology and electrical properties of layered copper selenide thin film

Open Physics ◽  
2009 ◽  
Vol 7 (2) ◽  
Author(s):  
J. Ying Chyi Liew ◽  
Zainal Talib ◽  
W. Mahmood ◽  
M. Yunus ◽  
Zulkarnain Zainal ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Surface Roughness ◽  
Grain Size ◽  
Copper Selenide ◽  
Layer By Layer ◽  
Structural Morphology ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Grain Size ◽  
Evaporation Technique

AbstractThin films of copper selenide (CuSe) were physically deposited layer-by-layer up to 5 layers using thermal evaporation technique onto a glass substrate. Various film properties, including the thickness, structure, morphology, surface roughness, average grain size and electrical conductivity are studied and discussed. These properties are characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), ellipsometer and 4 point probe at room temperature. The dependence of electrical conductivity, surface roughness, and average grain size on number of layers deposited is discussed.

scholarly journals Material microstructure effects in micro-endmilling of Cu99.9E

2016 ◽  
Vol 232 (7) ◽  
pp. 1143-1155 ◽  
Author(s):  
AM Elkaseer ◽  
SS Dimov ◽  
DT Pham ◽  
KP Popov ◽  
L Olejnik ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Chip Thickness ◽  
Micro Milling ◽  
Coarse Grained ◽  
Material Microstructure ◽  
Micro Cutting ◽  
Minimum Chip Thickness ◽  
Average Grain Size ◽  
Material Homogeneity

This article presents an investigation of the machining response of metallurgically and mechanically modified materials at the micro-scale. Tests were conducted that involved micro-milling slots in coarse-grained Cu99.9E with an average grain size of 30 µm and ultrafine-grained Cu99.9E with an average grain size of 200 nm, produced by equal channel angular pressing. A new method based on atomic force microscope measurements is proposed for assessing the effects of material homogeneity changes on the minimum chip thickness required for a robust micro-cutting process with a minimum surface roughness. The investigation has shown that by refining the material microstructure the minimum chip thickness can be reduced and a high surface finish can be obtained. Also, it was concluded that material homogeneity improvements lead to a reduction in surface roughness and surface defects in micro-cutting.

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