A generalized dynamic model for spindle vibration influencing surface topography in different ultra-precision machining processes

2018 ◽  
Vol 96 (5-8) ◽  
pp. 2471-2478 ◽  
Author(s):  
Zengwen Dong ◽  
Shaojian Zhang ◽  
Zhiwen Xiong ◽  
Xixin Rao
Keyword(s):  
Surface Topography ◽  
Dynamic Model ◽  
Precision Machining ◽  
Machining Processes ◽  
Ultra Precision ◽  
Spindle Vibration

scholarly journals Theoretical and Experimental Investigation of Surface Topography Generation in Slow Tool Servo Ultra-Precision Machining of Freeform Surfaces

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2566 ◽  
Author(s):  
Duo Li ◽  
Zheng Qiao ◽  
Karl Walton ◽  
Yutao Liu ◽  
Jiadai Xue ◽  
...  
Keyword(s):  
Surface Topography ◽  
Tool Path ◽  
Tool Path Generation ◽  
Surface Generation ◽  
Precision Machining ◽  
Path Generation ◽  
Freeform Surfaces ◽  
Ultra Precision ◽  
Slow Tool Servo ◽  
Radius Compensation

Freeform surfaces are featured with superior optical and physical properties and are widely adopted in advanced optical systems. Slow tool servo (STS) ultra-precision machining is an enabling manufacturing technology for fabrication of non-rotationally symmetric surfaces. This work presents a theoretical and experimental study of surface topography generation in STS machining of freeform surfaces. To achieve the nanometric surface topography, a systematic approach for tool path generation was investigated, including tool path planning, tool geometry selection, and tool radius compensation. The tool radius compensation is performed only in one direction to ensure no high frequency motion is imposed on the non-dynamic axis. The development of the surface generation simulation allows the prediction of the surface topography under various tool and machining variables. Furthermore, it provides an important means for better understanding the surface generation mechanism without the need for costly trial and error tests. Machining and measurement experiments of a sinusoidal grid and microlens array sample validated the proposed tool path generation and demonstrated the effectiveness of the STS machining process to fabricate freeform surfaces with nanometric topography. The measurement results also show a uniform topography distribution over the entire surface and agree well with the simulated results.

COINCIDENCE OF THE TECHNOLOGY AND THE SURFACE TOPOGRAPHY OF SPHERICAL ELEMENTS OCCURING DURING MACHINING PROCESS OF HIGH PRECISION

Tribologia ◽  
2016 ◽  
Vol 270 (6) ◽  
pp. 83-94 ◽  
Author(s):  
Magdalena NIEMCZEWSKA-WÓJCIK
Keyword(s):  
Titanium Alloy ◽  
Surface Topography ◽  
Machining Process ◽  
Precision Machining ◽  
Abrasive Machining ◽  
Precision Grinding ◽  
Machining Processes ◽  
Coordinate Measurement ◽  
Coordinate Measurement Machine ◽  
Spherical Elements

The paper presents issues concerning the surface layer and the changes in surface topography with respect to spherical elements at the subsequent stages of manufacturing process. Special attention was paid to the forming of surface topography in precision machining processes (preliminary grinding, precision grinding, lapping with polishing). The subjects of research and analysis were spherical elements made of a biomaterial, i.e. titanium alloy (Ti-6.5Al-1.3Si-2Zr). The surfaces of the studied components shaped during the subsequent operations of abrasive machining processes were measured using a coordinate measurement machine (CMM) and a white light interferometer (WLI). Based on the obtained results, the changes in the surface topography of metallic spherical elements brought about during the subsequent operations of precision machining processes were assessed. In addition to this, functional properties of these surfaces were identified.

scholarly journals Characterization of Surface Topography Variation in the Ultra-Precision Tool Servo-Based Diamond Cutting of 3D Microstructured Surfaces

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1448
Author(s):  
Wei Yuan ◽  
Chi-Fai Cheung
Keyword(s):  
Surface Topography ◽  
Dynamic Model ◽  
Cutting Speed ◽  
Surface Generation ◽  
Dynamic Force ◽  
Diamond Cutting ◽  
Microstructured Surfaces ◽  
Ultra Precision ◽  
Cutting System

Previous models of the relative tool-work vibration are not generalized to represent the surface generation mechanism in the ultra-precision tool servo-based diamond cutting (UTSDC) of three-dimensional (3D) microstructured surfaces. This is due to the fact that the tool-work vibration in UTSDC is no longer a steady harmonic vibration with a constant amplitude but is influenced by the tool motion along the thrust direction. In this paper, dynamic modeling of the cutting system is presented for the characterization of surface topography variation in UTSDC of a microlens array considering the tool-work vibration as an underdamped vibration. The natural frequency and damping ratio of the cutting system are determined by the data-dependent systems (DDS) method. Based on the analysis of the surface profile and cutting force signals, it is found that the tool-work vibration is significantly enhanced in the cut-in process when the cutting speed increases. The simulation results show that the proposed dynamic model can well-determine root-mean-squares RMS values of the surface primary profile and the dynamic force acting on the force sensor. The dynamic model provides insight into the formation of the surface topography variation in UTSDC of 3D microstructured surfaces, and the model might be applied in self-optimized machining systems in the future.

Effect of motor rotor eccentricity on aerostatic spindle vibration in machining processes

2017 ◽  
Vol 232 (7) ◽  
pp. 1331-1342 ◽  
Author(s):  
Quanhui Wu ◽  
Yazhou Sun ◽  
Wanqun Chen ◽  
Guoda Chen ◽  
Qingshun Bai ◽  
...  
Keyword(s):  
Electromechanical Coupling ◽  
Dihydrogen Phosphate ◽  
Mechanical Method ◽  
Motorized Spindle ◽  
Machining Processes ◽  
Rotor Eccentricity ◽  
Ultra Precision ◽  
Spindle Vibration ◽  
The Impact ◽  
Aerostatic Spindle

In ultra-precision machining field, the air motorized spindle which is composed of a motor and an air bearing, plays a major role. In air motorized spindle, the motor eccentricity between the stator and the rotor is inevitably introduced during the manufacturing process, which directly affects the machining results of workpiece surface, and this phenomenon is particularly unwanted in machining. However, little attention has been paid to the motor eccentricity of air motorized spindle. In this paper, a new integrated electromechanical coupling method for estimating unbalanced force in air motorized spindle is presented, and the effects of motor rotor eccentricity on surface topography in ultra-precision processes are analyzed. An electromagnetic-mechanical method is used to study the coupling effects between the motor rotor and the aerostatic spindle. Meanwhile, the motor rotor and the aerostatic spindle are analyzed as a whole. In order to clearly describe the electromagnetic–mechanical method, the ultra-precision spindle for potassium dihydrogen phosphate crystal machining tool is selected as the research object, and the model of air motorized spindle and motor rotor eccentricity are presented. Besides, in order to assess the impact of the radial magnetic force caused by motor rotor eccentricity on the spindle performance, a range of rotor eccentricities is calculated. Additionally, the influence of the motor rotor eccentricity on the dynamic response of spindle is further analyzed. It is found that motor rotor eccentricity has a significant influence on the spindle vibration, which dramatically reduces the processing quality. Finally, the machining experiments are carried out, and the flatness errors of the workpiece caused by the motor rotor eccentricity are obtained by the wavelet method. The experimental results are consistent with the analysis results, which verifies the reliability of this method. This study is quite meaningful for deeply understanding the influence of motor rotor eccentricity on the machined surface.

Progress of Traditional Ultra-Precision Machining Processes

2013 ◽  
Vol 753-755 ◽  
pp. 314-317 ◽  
Author(s):  
Zi Xu Han ◽  
Li Bao An ◽  
Hai Dong Zhao
Keyword(s):  
Manufacturing Technology ◽  
Precision Machining ◽  
Machining Parameters ◽  
Machining Processes ◽  
Structured Surfaces ◽  
Good Surface ◽  
Industrial Sectors ◽  
High Form ◽  
Ultra Precision ◽  
Good Surface Roughness

Ultra-precision machining is in the forefront of advanced manufacturing technology and also will become the basis of future manufacturing technology. Ultra-precision machining already has turned into the enabling technology to success in the international competition. Some new progresses in traditional ultra-precision machining processes including processing and measuring techniques, machining equipment, and analysis methods are introduced in this paper. Components with high form accuracy and good surface roughness are widely applied to precision apparatuses. Structured surfaces can be acquired by selecting reasonable machining parameters before mechanical process. The continuous growing markets will fuel many industrial sectors by ultra precision machining. We should pay great attention to the further developments of this technology.

Current Situation and Trend of Ultra-Precision Abrasive Machining

2007 ◽  
Vol 364-366 ◽  
pp. 690-695
Author(s):  
Ju Long Yuan ◽  
D.X. Hu ◽  
Zhi Wei Wang ◽  
Dong Hui Wen
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Development Trend ◽  
Precision Machining ◽  
Abrasive Machining ◽  
Machining Processes ◽  
Increasing Trend ◽  
Ultra Precision ◽  
The Development Trend ◽  
Fixed Abrasive

With increasing trend toward automatic manufacture and demands for improved quality, position of ultra-precision machining processes is considered as more and more important. As the main processes of ultra-precision machining, abrasive machining processes can be chiefly divided into free abrasive processes and fixed abrasive processes. Typical techniques such as chemicalmechanical polishing, ELID, Flat Honing and so on have been reviewed and compared with each other in preliminary aspects such as surface quality, finish accuracy and finish efficiency. The development trend of ultra-precision abrasive machining will have great efforts on realizing the integration with high accuracy, high efficiency and low cost.

scholarly journals A Self-Established “Machining-Measurement-Evaluation” Integrated Platform for Taper Cutting Experiments and Applications

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 929
Author(s):  
Xudong Yang ◽  
Zexiao Li ◽  
Linlin Zhu ◽  
Yuchu Dong ◽  
Lei Liu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Precision Machining ◽  
Two Dimensional ◽  
Dimensional Image ◽  
Two Dimensional Image ◽  
Integrated Platform ◽  
Hard And Brittle Materials ◽  
Ultra Precision ◽  
Cutting Experiments

Taper-cutting experiments are important means of exploring the nano-cutting mechanisms of hard and brittle materials. Under current cutting conditions, the brittle-ductile transition depth (BDTD) of a material can be obtained through a taper-cutting experiment. However, taper-cutting experiments mostly rely on ultra-precision machining tools, which have a low efficiency and high cost, and it is thus difficult to realize in situ measurements. For taper-cut surfaces, three-dimensional microscopy and two-dimensional image calculation methods are generally used to obtain the BDTDs of materials, which have a great degree of subjectivity, leading to low accuracy. In this paper, an integrated system-processing platform is designed and established in order to realize the processing, measurement, and evaluation of taper-cutting experiments on hard and brittle materials. A spectral confocal sensor is introduced to assist in the assembly and adjustment of the workpiece. This system can directly perform taper-cutting experiments rather than using ultra-precision machining tools, and a small white light interference sensor is integrated for in situ measurement of the three-dimensional topography of the cutting surface. A method for the calculation of BDTD is proposed in order to accurately obtain the BDTDs of materials based on three-dimensional data that are supplemented by two-dimensional images. The results show that the cutting effects of the integrated platform on taper cutting have a strong agreement with the effects of ultra-precision machining tools, thus proving the stability and reliability of the integrated platform. The two-dimensional image measurement results show that the proposed measurement method is accurate and feasible. Finally, microstructure arrays were fabricated on the integrated platform as a typical case of a high-precision application.

Sign in / Sign up

Export Citation Format

Share Document