The Current State and Development Trends of Deterministic Ultraprecision Optical Surfaces Machining Technology

2007 ◽  
Vol 364-366 ◽  
pp. 351-357
Author(s):  
Song Bao Luo ◽  
Hui Yang ◽  
Jian Ming Zhang ◽  
Chang Tao Pang
Keyword(s):  
Single Point ◽  
Diamond Turning ◽  
Ultraprecision Machining ◽  
Development Trends ◽  
Current State ◽  
Quantum Leap ◽  
Computer Controlled ◽  
Magneto Rheological ◽  
Technical Features ◽  
Accuracy And Repeatability

The deterministic ultraprecision machining achieves accuracy and repeatability not possible using conventional optical machining techniques, greatly enhances product quality, providing a quantum leap in throughput, productivity, yield, and cost effectiveness. The deterministic ultraprecision machining technology, involving various ultraprecision process from turning, flycutting, grinding and polishing to finishing, is usually referred to the following technologies such as single point diamond turning (SPDT), deterministic microgrinding (DMG), magneto-rheological finishing (MRF),computer controlled polishing (CCP), and computer controlled optical surfacing(CCOS),etc. This paper discusses mainly the current state and development trends of the deterministic ultraprecision machining technologies at home and abroad. In addition, the paper also elaborates on the technical features of the various deterministic machining technologies mentioned.

Simulation of Large Scale KDP Crystal Polishing by Computer Controlled Micro-Nano Deliquescence

2012 ◽  
Vol 497 ◽  
pp. 165-169 ◽  
Author(s):  
He Ping Zhang ◽  
Dong Ming Guo ◽  
Xu Wang ◽  
Hang Gao
Keyword(s):  
Large Scale ◽  
Surface Condition ◽  
Single Point ◽  
Damage Threshold ◽  
Diamond Turning ◽  
Water Soluble ◽  
Optical Elements ◽  
Kdp Crystal ◽  
Computer Controlled ◽  
Laser Induced Damage

Although Single Point Diamond Turning (SPDT) can do pretty well in optical surfacing of large scale KDP crystal, both the surface accuracy and integrity are considerably high; meanwhile as the defects of micro-waveness and stress are inevitable, the laser-induced damage threshold of KDP optical elements after SPDT still cannot be satisfied. Because of the characters of deliquescent and water-soluble, the process of computer controlled Micro-nano deliquescence is attempted to remove the residual micro-waveness on KDP surface after SPDT. Based on the assumption of Preston and the characters of Micro-nano deliquescence, the model of material removal ratio is suggested, the dwell time for ascertained KDP surface is solved, the processing of computer controlled Micro-nano deliquescence is simulated and the processed surface condition on theory is obtained. Besides, the influences of different parameters on the surfacing efficiency and accuracy are analyzed. Finally, three polishing tracks are comparatively analyzed. The simulation results are quite important in guiding the experimental polishing of large scale KDP by computer controlled Micro-nano deliquescence

Investigation on multi-body dynamics based approach to the toolpath generation for ultraprecision machining of freeform surfaces

2019 ◽  
Vol 234 (3) ◽  
pp. 571-583 ◽  
Author(s):  
Ali Khaghani ◽  
Kai Cheng
Keyword(s):  
Rotational Symmetry ◽  
Single Point ◽  
Equations Of Motion ◽  
Critical Role ◽  
Diamond Turning ◽  
Ultraprecision Machining ◽  
Time Step ◽  
Freeform Surfaces ◽  
Time Step Size ◽  
Toolpath Generation

This article presents an innovative approach to toolpath generation for ultraprecision machining of freeform optic surfaces based on the principle of Automatic Dynamics Analysis of Mechanical Systems. As components with freeform surfaces often have non-rotational symmetry, there are potential challenges facing their ultraprecision machining through single-point diamond turning, such as the projected points in complex large sag surfaces, which likely find it difficult to communicate with the control system and, thus, do not perform successfully. In ultraprecision machining, to achieve the highest performance in freeform surface resolution, the factors of dynamics, material and mechanical stiffness, frictions, tooling and accuracy of the servo component should be considered. The investigation is focused on an integrated approach and the associated scientific understanding of precision engineering design, ultraprecision machining and metrology of freeform surfaces as well as their application perspective. In this approach, the toolpath for very complex freeform surfaces can be generated using the Newton–Raphson method to solve the kinematics and dynamics equations of motion. The effect of friction and contact force are also investigated for accurate toolpath curve generation. Moreover, the Gear stiff (GSTIFF)/ Wielenga stiff (WSTIFF) integrator for solving the non-linear equations of motion is employed, and the result shows the time step size, playing a critical role in generating toolpath curves with a higher accuracy and resolution.

CURRENT STATE AND DEVELOPMENT TRENDS FISHING INDUSTRY OF THE RUSSIAN FEDERATION

2020 ◽  
Author(s):  
Anastasia Alekseevna Ilgeeva ◽  
Keyword(s):  
Russian Federation ◽  
Fish Farming ◽  
Economic Indicators ◽  
Fishing Industry ◽  
Development Trends ◽  
Fish Products ◽  
Current State ◽  
The Russian Federation

The article analyzes the volume of catch of aquatic bioresources in the Russian Federation and exports of fish products, as well as the main economic indicators of organizations by type of activity "Fishing, fish farming ". The main companies representing the Russian fish products market are considered. Recommendations are given on the prospects for the development of the fishing industry in the Russian Federation.

Tool interference at workpiece centre in single-point diamond turning

2019 ◽  
Vol 151 ◽  
pp. 1-12 ◽  
Author(s):  
Guoqing Zhang ◽  
Yuqi Dai ◽  
Suet To ◽  
Xiaoyu Wu ◽  
Yan Lou
Keyword(s):  
Single Point ◽  
Diamond Turning ◽  
Tool Interference
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