Modelling of Ultra-Precision Turning Processes in Consideration of Unbalances

2011 ◽  
Vol 223 ◽  
pp. 839-848 ◽  
Author(s):  
Christina Brandt ◽  
Jenny Niebsch ◽  
Jost Vehmeyer
Keyword(s):  
Surface Quality ◽  
High Surface ◽  
Machining Process ◽  
Surface Generation ◽  
Generation Process ◽  
Optical Components ◽  
Diamond Machining ◽  
Precision Turning ◽  
Ultra Precision ◽  
Machine Interaction

In order to manufacture optical components or mechanical parts with high surface roughness requirements, diamond machining is used. To achieve the desired surface quality, the understanding of the surface generation process and its influencing parameters is important. Here, the crucial parameter is the residual unbalance of the main spindle. As the residual un-balance affects the process and vice versa, the investigation of the process-machine interaction is necessary. In this paper we present a model describing this interaction between dynamical unbalances that occur during the machining process and the engine-shaft structure at the example of an ultra-precision turning lathe. This model allows the determination of the achievable surface quality of a workpiece for a given balancing state. On the other hand we will present a mathematical method to solve the corresponding inverse problem of computing the necessary residual balancing state and balancing weights for a given desired or given measured surface quality.

Fabrication of Micro V-Grooves in Ultra-Precision Grinding

2016 ◽  
Vol 679 ◽  
pp. 179-183
Author(s):  
Ze Qin Lin ◽  
Su Juan Wang ◽  
Xin Du Chen
Keyword(s):  
Fiber Optics ◽  
Surface Quality ◽  
Prediction Models ◽  
High Surface ◽  
Surface Generation ◽  
Precision Grinding ◽  
High Surface Quality ◽  
Ductile Mode ◽  
Ultra Precision ◽  
General Aspects

Ultra-precision grinding is an effective method to machine the optical micro v-groove, which is one of microstructures applied to the fiber-optics connectors, displays and other photonics devices. The ultra-precision grinding technology directly obtains high surface quality for brittle materials when the grinding process is under the ductile mode. This paper introduces general aspects of ultra-precision grinding technology in the fabrication of the micro v-grooves structures and introduces the essential features of ultra-precision grinding. The process of the manufacturing of the optical micro v-grooves components is presented in this paper. It contains the prediction models of surface roughness and form accuracy in the ultra-precision grinding and the optimization model under the consideration of the influences of grinding parameters,grinder factors and the material properties on the surface quality and machining efficiency. This study therefore contributes to providing a further understanding on the mechanisms of material removal and surface generation in ultra-precision girnding.

scholarly journals Electropolishing Parametric Optimization of Surface Quality for the Fabrication of a Titanium Microchannel Using the Taguchi Method

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 325
Author(s):  
Muslim Mahardika ◽  
Martin Andre Setyawan ◽  
Tutik Sriani ◽  
Norihisa Miki ◽  
Gunawan Setia Prihandana
Keyword(s):  
Taguchi Method ◽  
Surface Quality ◽  
Process Parameters ◽  
Applied Voltage ◽  
High Surface ◽  
Machining Process ◽  
Machining Parameters ◽  
Pareto Analysis ◽  
High Surface Quality

Titanium is widely used in biomedical components. As a promising advanced manufacturing process, electropolishing (EP) has advantages in polishing the machined surfaces of material that is hard and difficult to cut. This paper presents the fabrication of a titanium microchannel using the EP process. The Taguchi method was adopted to determine the optimal process parameters by which to obtain high surface quality using an L9 orthogonal array. The Pareto analysis of variance was utilized to analyze the three machining process parameters: applied voltage, concentration of ethanol in an electrolyte solution, and machining gap. In vitro experiments were conducted to investigate the fouling effect of blood on the microchannel. The result shows that an applied voltage of 20 V, an ethanol concentration of 20 vol.%, and a machining gap of 10 mm are the optimum machining parameters by which to enhance the surface quality of a titanium microchannel. Under the optimized machining parameters, the surface quality improved from 1.46 to 0.22 μm. Moreover, the adhesion of blood on the surface during the fouling experiment was significantly decreased, thus confirming the effectiveness of the proposed method.

Modeling the Material Microstructure Effects on the Surface Generation Process in Microendmilling of Dual-Phase Materials

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
A. M. Abdelrahman Elkaseer ◽  
S. S. Dimov ◽  
K. B. Popov ◽  
M. Negm ◽  
R. Minev
Keyword(s):  
Chip Thickness ◽  
Machining Process ◽  
Surface Generation ◽  
Dual Phase ◽  
Generation Process ◽  
Phase Boundaries ◽  
Material Microstructure ◽  
Workpiece Material ◽  
Multiphase Materials ◽  
Proposed Model

The anisotropic behavior of the material microstructure when processing multiphase materials at microscale becomes an important factor that has to be considered throughout the machining process. This is especially the case when chip-loads and machined features are comparable in size to the cutting edge radius of the tool, and also similar in scale to the grain sizes of the phases present within the material microstructure. Therefore, there is a real need for reliable models, which can be used to simulate the surface generation process during microendmilling of multiphase materials.This paper presents a model to simulate the surface generation process during microendmilling of multiphase materials. The proposed model considers the effects of the following factors: the geometry of the cutting tool, the feed rate, and the workpiece material microstructure. Especially, variations of the minimum chip thickness at phase boundaries are considered by feeding maps of the material microstructure into the model. Thus, the model takes into account these variations that alter the machining mechanism from a proper cutting to ploughing and vice versa, and are the main cause of microburr formation. By applying the proposed model, it is possible to estimate more accurately the resulting roughness because the microburr formation dominates the surface generation process during microendmilling of multiphase materials. The proposed model was experimentally validated by machining two different samples of dual-phase steel under a range of chip-loads. The roughness of the resulting surfaces was measured and compared to the predictions of the proposed model under the same cutting conditions. The results show that the proposed model accurately predicts the roughness of the machined surfaces by taking into account the effects of material multiphase microstructure. Also, the developed model successfully elucidates the mechanism of microburr formation at the phase boundaries, and quantitatively describes its contributions to the resulting surface roughness after microendmilling.

Precision Mould Making – From Macro to Micro

2010 ◽  
Vol 447-448 ◽  
pp. 1-8 ◽  
Author(s):  
Ekkard Brinksmeier ◽  
Jen Osmer
Keyword(s):  
High Surface ◽  
Hot Embossing ◽  
Diamond Turning ◽  
Advanced Materials ◽  
Precision Grinding ◽  
Machining Processes ◽  
Optical Components ◽  
Diamond Machining ◽  
Optical Glasses ◽  
Optical Applications

Nowadays several qualified technologies have been established for the manufacturing of precision moulds. The fields of application can mainly be divided into moulds for non-optical and optical components. For optical moulding inserts the development goes from basic rotational symmetric geometries to complex surfaces like steep aspheres and freeforms which can additionally be overlaid with microstructures. The moulded components require a figure accuracy in the (sub-) micrometer and surface roughness in the nanometer range while moulds for replication also need advanced materials with high surface integrity. Here, diamond machining processes, e.g. diamond turning and milling as well as precision grinding and polishing are necessary for the manufacturing of precision moulding inserts from various materials. Depending on the material and application of the applied part to be replicated different replication techniques are used like injection moulding of plastics, hot embossing and precision moulding of optical glasses. For non-optical applications the current technical progress is driven by miniaturized products which are typically produced in mass production by replication techniques like hot embossing or metal forming. Each of these processes requires specific properties of the mould. Therefore, the surface topography and tribological conditions are of particular importance.

Experimental Investigation on Hybrid Technology of Ultrasonic Vibration Assisted Chemo-Mechanical Grinding (CMG) Silicon Wafer

2013 ◽  
Vol 275-277 ◽  
pp. 2290-2294
Author(s):  
Wei Ping Yang ◽  
Yong Bo Wu ◽  
Jun Liu
Keyword(s):  
Surface Quality ◽  
Silicon Wafer ◽  
Ultrasonic Vibration ◽  
Substrate Surface ◽  
High Surface ◽  
Machining Process ◽  
Hybrid Technique ◽  
Mechanical Grinding ◽  
Vibration Assistance ◽  
Profile Accuracy

For the final finishing of the substrate surface, Chemo-mechanical polishing (CMP) is often utilized. Those processes are able to offer a great sur-face roughness, but sacrifice profile accuracy. On the other hand, Chemo-mechanical grinding (CMG) is potentially emerging defect-free machining process which combines the advantages of CMP. In order to simultaneously achieve high surface quality and high profile accuracy, CMG process has been applied into machining of large size quartz glass substrates for photomask use. In this paper, based on the characteristics of higher machining efficiency and higher surface quality of ultrasonic vibration machining, a new ultrasonic vibration assisted CMG of silicon wafer hybrid technique is achieved by designing elliptical vibrator with longitudinal mode and bending mode. The experimental results show that under the elliptic ultrasonic vibration assistance, the surface roughness is decreased significantly, the surface quality is improved obviously, and moreover caused little or even doesn’t lead to the surface damage.

scholarly journals Study on Surface Quality factors of 10 B / Al Composite In Ultra - Precision Turning

Procedia CIRP ◽  
2018 ◽  
Vol 71 ◽  
pp. 75-78 ◽  
Author(s):  
Wang Xingjun ◽  
Wang Liping ◽  
Wang Wei ◽  
He Linshan
Keyword(s):  
Surface Quality ◽  
Quality Factors ◽  
Precision Turning ◽  
Al Composite ◽  
Ultra Precision

scholarly journals Theoretical prediction and experimental verification of the unbalanced magnetic force in air bearing motor spindles

2019 ◽  
Vol 233 (12) ◽  
pp. 2330-2344 ◽  
Author(s):  
Quanhui Wu ◽  
Yazhou Sun ◽  
Wanqun Chen ◽  
Qing Wang ◽  
Guoda Chen
Keyword(s):  
Surface Topography ◽  
Surface Quality ◽  
Magnetic Force ◽  
Research Work ◽  
Diamond Turning ◽  
Surface Generation ◽  
Air Bearing ◽  
Machined Surface ◽  
Spindle Shaft ◽  
Ultra Precision

Dynamic vibrations of air bearing motor spindles have significant influence on the surface quality in ultra-precision machining. In this article, the influence of the vibration caused by the unbalanced magnetic force on the diamond turning is investigated on the basis of the theoretical and experimental method. A permanent magnet motor model (10 poles and 12 slots) is built and then simulated to gain a periodic unbalanced magnetic force. The effects of unbalanced magnetic force on the inclination of the spindle shaft is analyzed, which would affect the surface quality of the workpiece, and the surface topography of the workpiece is predicted during an unbalanced magnetic force acting on air bearing motor spindle. The theoretical analysis and experimental turning results validate that the angle between the direction of unbalanced magnetic force and the feed direction has a certain relationship with the profile of the machined surface. Also, under different turning speeds and directions, the surface topography of the machined workpiece shows a 10-cycle-per-revolution pattern, which has good agreement with the simulations of periodic unbalanced magnetic force. This research work provides a theoretical foundation for the fault diagnosis of air bearing motor spindle caused by motor rotor eccentricity and its effect on surface generation in turning.

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