scholarly journals Ultra-High-Speed Magnetic Abrasive Surface Micro-Machining of AISI 304 Cylindrical Bar

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 489 ◽  
Author(s):  
Cheng Yin ◽  
Rui Wang ◽  
Jeong Kim ◽  
Sang Lee ◽  
Sang Mun
Keyword(s):  
Surface Roughness ◽  
Plastic Strain ◽  
High Speed ◽  
Precision Machining ◽  
Plastic Strains ◽  
Abrasive Machining ◽  
Machined Surface ◽  
Aisi 304 ◽  
Ultra High Speed ◽  
Ultra Precision

The ultra-high-speed magnetic abrasive machining (UHSMAM) process is a surface improvement technique, which has been widely used to minimize the surface accuracy and change the precision morphology of difficult-to-machine materials. Surface integrity plays an important role in the machining process, because it is used to evaluate the high stress and the loaded components on the machined surface. It is important to evaluate the plastically deformed layers in ultra-precision machining surface of material. However, the usual plastic strains in the ultra-precision machining surface are significantly difficult to consider. In this paper, an ultra-high-speed magnetic abrasive machining technique is used to improve the surface accuracy and dimensional accuracy of an AISI 304 bars. Additionally, the subsequent recrystallizations technique is used for measuring the plastic strain on machined surface of AISI 304 bars. The purpose of this paper is to evaluate the effects of an UHSMAM process on the plastic strains and the strain energy of the machined surface, and to evaluate the residual strain in the plastic deformation of AISI 304 bars materials by analyzing a plastically deformed layer. The results showed that the plastic strain of the material did not change after machined by an UHSMAM process. Based on the results, an UHSMAM process could significantly improve the surface roughness, micro-diameter, and removal weight of AISI 304 bars effectively. The surface roughness Ra of AISI 304 bars was improved from 0.32 µm to 0.03 µm for 40 s of machining time at 80,000 rpm of workpiece revolution speed.

Characterization of Cutting-Induced Heat Generation in Ultra-Precision Milling of Aluminium Alloy 6061

2013 ◽  
Vol 552 ◽  
pp. 201-206
Author(s):  
Su Juan Wang ◽  
Suet To ◽  
Xin Du Chen
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Heat Generation ◽  
Feed Rate ◽  
Dimensional Accuracy ◽  
Precision Machining ◽  
Machined Surface ◽  
Single Crystal Diamond ◽  
Ultra Precision ◽  
Alloy 6061

The technology of ultra-precision machining with single crystal diamond tool produces advanced components with higher dimensional accuracy and better surface quality. The cutting-induced heat results in high temperature and stress at the chip-tool and tool-workpiece interfaces therefore affects the materials and the cutting tool as well as the surface quality. In the ultra-precision machining of al6061, the cutting-induced heat generates precipitates on the machined surface and those precipitates induce imperfections on the machined surface. This paper uses the time-temperature-precipitation characteristics of aluminum alloy 6061 (al6061) to investigate the effect of feed rate on the cutting-induced heat generation in ultra-precision multi-axis milling process. The effect of feed rate and feed direction on the generation of precipitates and surface roughness in ultra-precision raster milling (UPRM) is studied. Experimental results show that heat generation in horizontal cutting is less than that in vertical cutting and a larger feed rate generates more heat on the machined workpiece. A smaller feed rate produces a better surface finish and under a larger feed rate, scratch marks are produced by the generated precipitates and increase surface roughness.

Experimental Study of the Light Scattering Induced by the Surface Roughness of the Ultraprecision Machined Workpiece

2010 ◽  
Vol 143-144 ◽  
pp. 1091-1096
Author(s):  
Chun Der Cheng ◽  
Hsi Hsun Tsai ◽  
Hui Ping Feng
Keyword(s):  
Surface Roughness ◽  
Light Scattering ◽  
Measurement Technique ◽  
Precision Machining ◽  
Diode Array ◽  
Machined Surface ◽  
Tool Marks ◽  
Scattering Effect ◽  
Photo Diode ◽  
Ultra Precision

An in-situ measurement technique of the surface roughness of ultra-precision machining by optical characteristic effects is fundamental thanks to the probe-less which would avoid the contact damage on the surface. Since the plastic lens molding reprints the roughness from the mould core fabricated by machining, the tool marks induce the poor surface of the plastic lens. By a laser with a short wavelength of He-Ne of 632 nanometers, the machined surface would reflect the input light. Several samples with different surface roughness of the aluminum by varying the feed rate of the ultra-precision machining are used to be measured by the He-Ne laser. The 1 x 16 photo-diode array with the pitch of 2.0 mm is constructed to measure the distribution of the optical scattering effect under the light source of He-Ne laser. Results show that the higher surface roughness gives a more expanse distribution of the light scattering. Besides, the BSDF of the machined surface is proportional to roughness. Using the ratio of the main and side measuring channels of the photo-diode array would give a suitable approach to construct the relationship between the light scattering and surface roughness. Therefore, the laser and the photodiode array would predict well the roughness of the ultra-precision machined surfaces of aluminum. The on-line measurement technique for the roughness by reflected light scattering effect from the ultra-precision machined surface is constructed nice in this study.

Effects of the Tool Angles on the Machined Surface Quality of KDP Crystal in Diamond Turning

2007 ◽  
Vol 364-366 ◽  
pp. 297-301 ◽  
Author(s):  
Jing He Wang ◽  
Ming Jun Chen ◽  
Shen Dong ◽  
Shi Qian Wang
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Rake Angle ◽  
Diamond Turning ◽  
Precision Machining ◽  
Machined Surface ◽  
Kdp Crystal ◽  
Factors Affecting ◽  
Ultra Precision ◽  
Back Angle

In the ultra-precision machining of KDP crystal, there are many factors affecting the surface quality[1-3]. The experiments show that the rake angle and back angle of the tool have significant effects on machined surface roughness. Therefore, an efficient way to improve the surface roughness is to select a proper negative rake angle. In this study, the ANSYS static analysis method was employed to analyze the stress field distribution within the whole cutting region. A finite element simulation model was set up to calculate the residual stresses variation with tool’s angles, which can be considered to select optimal rake and back angles in the ultra-precision machining of KDP crystal. Results show that the optimal tool rake angle and back angle are -49° and 7°, respectively. Finally, by using different tool angles to process KDP crystal and utilizing AFM to analyze the surface roughness, it can be found that the measurement results agree well with what are deduced from theoretical calculation.

Machining Characteristics of Semibonded Abrasive Grinding Plate

2008 ◽  
Vol 53-54 ◽  
pp. 173-178
Author(s):  
Ju Long Yuan ◽  
Yi Yang ◽  
Zhi Wei Wang ◽  
Dong Qiang Yu ◽  
Miao Qian ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Silicon Wafer ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Precision Machining ◽  
Wafer Surface ◽  
Abrasive Machining ◽  
Fine Surface ◽  
Ultra Precision ◽  
Machining Characteristics

This work aims to obtain fine surface of silicon wafer during precision and ultra precision machining, and presents a new method called semibonded abrasive machining. A semibonded abrasive grinding plate is used in the semibonded abrasive machining. Abrasive particle of 1000# Green SiC and bond named SSB are adopted in the manufacture of the plate. Four plates with different concentration of bond which are 1.5%, 2.5%, 3.5%, 4.5% respectively are made. The paper studies the effect of concentration of bond, the control parameters which include the lapping time, the load, and the rotating velocity of the plate on the surface roughness. Experimental results indicate each plate with different concentration of bond can obtain fine surface roughness. When the load or the rotating velocity increases, there is little effect on the surface roughness, but the material removal rate increases correspondingly. The initial roughness of the silicon wafer surface lapping by the plate could be improved from Ra 0.2μm to Ra 0.02μm in 9 min.

Machined Surface Characteristics and Removal Mechanism of Soft and Brittle Solids

2010 ◽  
Vol 447-448 ◽  
pp. 183-187 ◽  
Author(s):  
Zhen Yu Zhang ◽  
Rudy Irwan ◽  
Han Huang
Keyword(s):  
Surface Characteristics ◽  
Abrasive Machining ◽  
Precision Grinding ◽  
Machined Surface ◽  
Brittle Solids ◽  
The Coefficient Of Friction ◽  
Ultra Precision ◽  
Ductile Removal ◽  
Fracture Features ◽  
Free Abrasive

Surface characteristics of CZT wafers machined using wire sawing, free abrasives lapping and polishing and ultra-precision grinding were investigated. Wire sawing resulted in the removal of material in both ductile and brittle regimes, but both polishing and grinding led to a ductile removal. The grinding produced very smooth surfaces free of embeddings and scratches, which is thus considered to have better machinability than the free abrasive machining. The nanoindentation and nanoscratch on MCT wafers at nanometric scales resulted in considerable plastic deformation, but no fracture features. The hardness of the MCT wafer was 500 to 550 MPa, and the coefficient of friction was particularly high, ranging from 0.45 to 0.55.

Machining Evaluation of High-Speed Milling for Thin-Wall Machining of Al7075-T651

2014 ◽  
Vol 541-542 ◽  
pp. 785-791 ◽  
Author(s):  
Joon Young Koo ◽  
Pyeong Ho Kim ◽  
Moon Ho Cho ◽  
Hyuk Kim ◽  
Jeong Kyu Oh ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
Cutting Forces ◽  
High Speed ◽  
Surface Condition ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
Thin Wall ◽  
Machined Surface ◽  
High Speed Milling

This paper presents finite element method (FEM) and experimental analysis on high-speed milling for thin-wall machining of Al7075-T651. Changes in cutting forces, temperature, and chip morphology according to cutting conditions are analyzed using FEM. Results of machining experiments are analyzed in terms of cutting forces and surface integrity such as surface roughness and surface condition. Variables of cutting conditions are feed per tooth, spindle speed, and axial depth of cut. Cutting conditions to improve surface integrity were investigated by analysis on cutting forces and surface roughness, and machined surface condition.

Investigation of Surface Characteristics and Chip Morphology in High Speed Cutting of Inconel718 Based on SHPB System

2019 ◽  
Author(s):  
Zengqiang Wang ◽  
Zhanfei Zhang ◽  
Wenhu Wang ◽  
Ruisong Jiang ◽  
Kunyang Lin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Surface Profile ◽  
Chip Morphology ◽  
Depth Of Cut ◽  
Machined Surface ◽  
High Speed Cutting

Abstract High speed cutting (HSC) technology has the characteristics of high material removal rates and high machining precision. In order to study the relationships between chip morphology and machining surface characteristic in high speed cutting of superalloy Inconel718. High-speed orthogonal cutting experiment are carried out by used a high speed cutting device based on split Hopkinson pressure bar (SHPB). The specimen surfaces and collected chips were then detected with optical microscope, scanning electron microscope and three-dimensional surface profile measuring instrument. The results show that within the experimental parameters (cutting speed from 8–16m/s, depth of cut 0.1–0.5mm), the obtained chips are sawtooth chips and periodic micro-ripple appear on the machined surface. With the cutting speed increases, machining surface roughness is decreases from 1.4 to 0.99μm, and the amplitude of periodic ripples also decreases. With the cutting depth increases, the machining surface roughness increases from 0.96 to 5.12μm and surface topography becomes worse. With the increase of cutting speed and depth of cut, the chips are transform from continues sawtooth to sawtooth fragment. By comparing the frequency of surface ripples and sawtooth chips, it is found that they are highly consistent.

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