scholarly journals Fabrication of Sinusoidal Microstructures on Curved Copper Surface by Ultra-Precision Diamond Cutting with a Rotary B-Axis and Fast Tool Servo System

2021 ◽  
Vol 11 (21) ◽  
pp. 10302
Author(s):  
Xuesen Zhao ◽  
Haiping Du ◽  
Wenda Song ◽  
Qiang Zhang ◽  
Zhenjiang Hu ◽  
...  
Keyword(s):  
Tool Path ◽  
Servo System ◽  
Copper Surface ◽  
Curvature Radius ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Fast Tool Servo ◽  
Diamond Cutting ◽  
Sinusoidal Modulation ◽  
Ultra Precision

While curved surface microstructures have wide applications in optical components and devices, how to achieve high machining accuracy of the microstructures is crucial for their applications. In the present work, we fabricate sinusoidal modulation microstructures on a curved copper surface by ultra-precision diamond cutting, with the combination of a rotary B-axis and a fast tool servo system. Specifically, tool path planning, together with the consideration of a curved, sinusoidal surface meshing and tool tip arc segmentation compensation, is carried out. Preliminary cutting experiments are firstly carried out on a homemade four-axis ultra-precision lathe, which demonstrates the advantages of additionally applying the rotary B-axis in suppressing burr formations and over-cutting phenomenon over the sole utilization of the fast tool servo system. Subsequent experiments are carried out to evaluate the effects of feed rate and the number of sampling points on the machining accuracy of the microstructures under the combination of a rotary B-axis and a fast tool servo system. With the optimized machining parameters, sinusoidal modulation microstructures, which have a wavelength of 700.6 μm, a peak-to-valley of 18.7 μm, a surface roughness of 18.9 nm and a deviation of profile tolerance of 4.326 μm, are successfully fabricated on a curved copper surface with a face radius of 10 mm and a curvature radius of 500 mm.

Study on Single-Plane Biaxial Balance Monitor System in ULTRA-Precision Grinding

2006 ◽  
Vol 304-305 ◽  
pp. 251-255
Author(s):  
L. Zheng ◽  
Yin Biao Guo ◽  
Z.Z. Wang
Keyword(s):  
Mutual Influence ◽  
Machining Accuracy ◽  
Monitor System ◽  
Machining Parameters ◽  
Precision Grinding ◽  
Single Plane ◽  
Workpiece Surface ◽  
Surface Error ◽  
Vibration Data ◽  
Ultra Precision

This paper puts forward an intelligent single-plane biaxial balance monitor system, which is used in ultra-precision grinding. It adopts the method of single-plane balance correction for the vibration of wheel and workpiece. And this system can also be used for integral balance. For ultra-precision grinding, caused by the mutual influence of the vibration of wheel and workpiece, there will be a ripple on the workpiece surface, which is mainly influenced by the frequency ratio of wheel to workpiece, the feed rate and the vibration of wheel and workpiece. This system can improve the machining accuracy, reduce the surface error of workpiece and appraise the integrated machining result, by analyzing the vibration data of wheel and workpiece and adjusting machining parameters.

Analysis of Tangential Position Error or Removal Function Error in Ultrasonic-Magnetorheological Combined Finishing

2012 ◽  
Vol 516 ◽  
pp. 390-395
Author(s):  
Fei Hu Zhang ◽  
Xing Bin Yu ◽  
Yong Zhang
Keyword(s):  
Tool Path ◽  
Current Approach ◽  
Residual Error ◽  
Curvature Radius ◽  
Aspheric Surfaces ◽  
Form Errors ◽  
Positioning Errors ◽  
Ultra Precision ◽  
A New Technique ◽  
Low Amplitude

Ultrasonic-magnetorheological combined finishing (UMCF) is a new technique for the ultra precision machining of aspheric surfaces, especially for high quality work pieces with small curvature radius concave surfaces. The goal with UMCF is to minimize surface figure errors by optimizing the dwell time and tool path, and the current approach typically results in low amplitude form errors. However, discrepancies exist between the predicted and observed form errors. The major sources of such errors are machine axes positioning errors and unpredicted variations of the removal function. Errors that can produce discrepancies between actual and predicted removal profiles were modelled. A diagnostic method was developed to determine the residual error induced by two types of error. Their effects were examined with numerical simulations and the simulation result was presented. Finally, UMCF experiments are performed on a variety of optical surfaces. The final residual error after polishing is less than 2.6 nm PV values. The successful figuring results prove the validity and advantages of UMCF.

Fabrication of Freeform Optics in Ultra-Precision Raster Milling

2007 ◽  
Vol 339 ◽  
pp. 412-416 ◽  
Author(s):  
Su Juan Wang ◽  
Chi Fai Cheung ◽  
Sandy To ◽  
Wing Bun Lee
Keyword(s):  
Tool Path ◽  
Research Work ◽  
Tool Path Generation ◽  
Path Generation ◽  
Machining Parameters ◽  
Generation System ◽  
Primary Interest ◽  
High Productivity ◽  
Freeform Optics ◽  
Ultra Precision

Recently, the high quality and high productivity in fabrication of freeform optics has been of primary interest in manufacturing industries, such as die and mould manufacturing, aerospace part manufacturing, and so forth. However, the fabrication of freeform optics is currently expensive and vastly complex. Ultra-precision raster milling can produce non-rotational symmetric surfaces with sub-micrometric form accuracy and nanometric surface finish without the need for any subsequent post polishing. While, there is little research work focus on this kind of machining method. This paper presents a framework of a tool path generation system for freeform surface ultra-precision raster milling. This system includes model of freeform optics, tool path generator, interference monitor and an optimization model of machining parameters. The tool path generation system can generate interference free and optimal tool path for machining freeform surfaces. Some simulation results have been presented to illustrate the performance of the system.

A Study of Tool Path Generation for Machining of Precision Roller with Wavy Patterned Microstructures by Slow Tool Servo

2016 ◽  
Vol 679 ◽  
pp. 191-197
Author(s):  
Ling Bao Kong ◽  
Chi Fai Cheung ◽  
Wing Bun Lee ◽  
Suet To ◽  
Su Juan Wang ◽  
...  
Keyword(s):  
Tool Path ◽  
Single Point ◽  
Research Work ◽  
Axial Direction ◽  
Diamond Turning ◽  
Machining Process ◽  
Fast Tool Servo ◽  
Roller Surface ◽  
Ultra Precision ◽  
Slow Tool Servo

Embossing by patterned rollers is one of the most efficient machining approaches for manufacturing plastic films with patterned microstructures, and the precision roller with patterned microstructures is the key tooling component in the roll-to-roll process. Single-point diamond turning with a slow or fast tool servo is an enabling and efficient ultra-precision machining process to fabricate microstructures through a simple process to achieve optical surface finish directly. Most of the current studies on slow or fast tool servo machining processes either focus on face machining of patterned microstructures, or on tool servo machining of microstructures in the radial direction of precision rollers. Relatively little research work is found in relation to machining patterned microstructures on a precision roller by using the tool servo in the axial direction. This paper presents a pilot study on the development of a tool path generator for machining precision rollers with wavy patterned microstructures by using slow tool servo machining in the axial direction on a precision roller. The machining mechanism is firstly explained, based on which the tool path generator is developed for machining wavy patterned microstructures on a precision roller surface. Preliminary experimental work was conducted to study the generation of wavy patterned microstructures on a precision roller using a four-axis ultra-precision machine. The machined wavy microstructures on the roller surface are measured and analyzed to successfully validate the performance of the proposed tool path generator.

An Optimal Method of Tool Path Generation for Radial Sinusoidal Surface

2014 ◽  
Vol 1027 ◽  
pp. 20-23 ◽  
Author(s):  
Shi Jun Ji ◽  
Hui Juan Yu ◽  
Ji Zhao ◽  
Jin Chao Li ◽  
Lei Lei Liu
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Machining Accuracy ◽  
Path Generation ◽  
Optimal Method ◽  
Spiral Tool Path ◽  
Ultra Precision ◽  
Sinusoidal Surface ◽  
Theoretical Analyses

Tool path generation is an important part of ultra-precision manufacturing, and spiral tool path is one typical driving path. For single point diamond turning (SPDT), two methods are commonly used to generate the driving points on the spiral tool path, which are equally spaced angles and equally spaced arcs for two adjacent cutting points. But these two methods both have the defects for machining radial sinusoidal surface with SPDT. In this paper, the theoretical analyses of the two different methods are conducted and compared respectively. Then, an optimal method of generating the spiral cutting tool path is proposed on the base of theoretical analyses, which can avoid disadvantages of two original methods. The proposed method can enhance the machining accuracy and fabricating efficiency for ultra-precision machining of the radial sinusoidal surface with SPDT.

scholarly journals Study of ultrasonic vibration–assisted thread turning of Inconel 718 superalloy

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988377
Author(s):  
Yu He ◽  
Zhongming Zhou ◽  
Ping Zou ◽  
Xiaogang Gao ◽  
Kornel F Ehmann
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Inconel 718 ◽  
Gas Turbines ◽  
Tool Path ◽  
Machining Parameters ◽  
Thread Cutting ◽  
Workpiece Surface ◽  
Inconel 718 Superalloy ◽  
The Relationship

With excellent properties, high-temperature superalloys have become the main application materials for aircraft engines, gas turbines, and many other devices. However, superalloys are typically difficult to machine, especially for the thread cutting. In this article, an ultrasonic vibration–assisted turning system is proposed for thread cutting operations in superalloys. A theoretical analysis of ultrasonic vibration–assisted thread cutting is carried out. An ultrasonic vibration–assisted system was integrated into a standard lathe to demonstrate thread turning in Inconel 718 superalloy. The influence of ultrasonic vibration–assisted machining on workpiece surface quality, chip shape, and tool wear was analyzed. The relationship between machining parameters and ultrasonic vibration–assisted processing performance was also explored. By analyzing the motion relationship between tool path and workpiece surface, the reasons for improved workpiece surface quality by ultrasonic vibration–assisted machining were explained.

Error correction technique for numerical control machine tools based on the simplex method

2021 ◽  
pp. 095440542110281
Author(s):  
Hongwei Liu ◽  
Rui Yang ◽  
Pingjiang Wang ◽  
Jihong Chen ◽  
Hua Xiang
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Simplex Method ◽  
Tool Path ◽  
Repeated Measurements ◽  
Numerical Control ◽  
Machining Accuracy ◽  
Correction Technique ◽  
Fluctuation Range ◽  
Nc Machine

The objective of this research is to develop a novel correction mechanism to reduce the fluctuation range of tools in numerical control (NC) machining. Error compensation is an effective method to improve the machining accuracy of a machine tool. If the difference between two adjacent compensation data is too large, the fluctuation range of the tool will increase, which will seriously affect the surface quality of the machined parts in mechanical machining. The methodology used in compensation data processing is a simplex method of linear programming. This method reduces the fluctuation range of the tool and optimizes the tool path. The important aspect of software error compensation is to modify the initial compensation data by using an iterative method, and then the corrected tool path data are converted into actual compensated NC codes by using a postprocessor, which is implemented on the compensation module to ensure a smooth running path of the tool. The generated, calibrated, and amended NC codes were immediately fed to the machine tool controller. This technique was verified by using repeated measurements. The results of the experiments demonstrate efficient compensation and significant improvement in the machining accuracy of the NC machine tool.

scholarly journals An Investigation of the Cutting Strategy for the Machining of Polar Microstructures Used in Ultra-Precision Machining Optical Precision Measurement

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 755
Author(s):  
Chen-Yang Zhao ◽  
Chi-Fai Cheung ◽  
Wen-Peng Fu
Keyword(s):  
Precision Measurement ◽  
Detection Algorithm ◽  
Surface Generation ◽  
Precision Machining ◽  
Tool Geometry ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Ultra Precision ◽  
Transition Points ◽  
Cutting Strategy

In this paper, an investigation of cutting strategy is presented for the optimization of machining parameters in the ultra-precision machining of polar microstructures, which are used for optical precision measurement. The critical machining parameters affecting the surface generation and surface quality in the machining of polar microstructures are studied. Hence, the critical ranges of machining parameters have been determined through a series of cutting simulations, as well as cutting experiments. First of all, the influence of field of view (FOV) is investigated. After that, theoretical modeling of polar microstructures is built to generate the simulated surface topography of polar microstructures. A feature point detection algorithm is built for image processing of polar microstructures. Hence, an experimental investigation of the influence of cutting tool geometry, depth of cut, and groove spacing of polar microstructures was conducted. There are transition points from which the patterns of surface generation of polar microstructures vary with the machining parameters. The optimization of machining parameters and determination of the optimized cutting strategy are undertaken in the ultra-precision machining of polar microstructures.

scholarly journals Towards Efficient Milling of Multi-Cavity Aeronautical Structural Parts Considering ACO-Based Optimal Tool Feed Position and Path

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 88
Author(s):  
Yupeng Xin ◽  
Yuanheng Li ◽  
Wenhui Li ◽  
Gangfeng Wang
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Milling Process ◽  
Ant Colony ◽  
Machining Accuracy ◽  
Ant Colony Optimization Algorithm ◽  
Peripheral Milling ◽  
Structural Part ◽  
Milling Method ◽  
Structural Parts

Cavities are typical features in aeronautical structural parts and molds. For high-speed milling of multi-cavity parts, a reasonable processing sequence planning can significantly affect the machining accuracy and efficiency. This paper proposes an improved continuous peripheral milling method for multi-cavity based on ant colony optimization algorithm (ACO). Firstly, by analyzing the mathematical model of cavity corner milling process, the geometric center of the corner is selected as the initial tool feed position. Subsequently, the tool path is globally optimized through ant colony dissemination and pheromone perception for path solution of multi-cavity milling. With the advantages of ant colony parallel search and pheromone positive feedback, the searching efficiency of the global shortest processing path is effectively improved. Finally, the milling programming of an aeronautical structural part is taken as a sample to verify the effectiveness of the proposed methodology. Compared with zigzag milling and genetic algorithm (GA)-based peripheral milling modes in the computer aided manufacturing (CAM) software, the results show that the ACO-based methodology can shorten the milling time of a sample part by more than 13%.

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