scholarly journals Ductile behavior of optical glass in single point diamond turning

2014 ◽  
Vol 67 (2) ◽  
pp. 167-172
Author(s):  
Carlos Renato Pagotto ◽  
Jaime Gilberto Duduch ◽  
Renato Goulart Jasinevicius
Keyword(s):  
Optical Glass ◽  
Elastic Recovery ◽  
Single Point ◽  
Tool Material ◽  
Diamond Turning ◽  
Machined Surface ◽  
Force Microscopy ◽  
Semiconductor Crystals ◽  
Ductile Machining ◽  
Ductile Behavior

Single point diamond turning tests were carried out on a B270 type glass. Submicrometer cutting conditions were applied in order to generate ductile response during single point machining. The profile generated by the rapid removal of the tool tip from the machined surface, analyzed by atomic force microscopy, showed that the brittle-to-ductile transition occurs at a few tenths of micrometers. According to the machining results, the maximum feed rate capable of generating a ductile mode machining behavior is of 0.9 micrometer/revolution. Furthermore, it was shown that with the cutting depth lower than 0.100 micrometer/revolution, the material removal mechanism is totally ductile. Ribbon-like chips were not observed when ductile machining was performed, as commonly seen during ductile machining of semiconductor crystals. The chips removed had a small needle-like shape. This material's fragile behavior during machining may be related to high densification during tool/material interaction with subsequent elastic recovery response.

Optical Effects of Surface Finish by Ultraprecision Single Point Diamond Machining

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Lei Li ◽  
Stuart A. Collins ◽  
Allen Y. Yi
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Diamond Turning ◽  
Optical Diffraction ◽  
Machining Process ◽  
Machined Surface ◽  
Tool Marks ◽  
Tool Mark ◽  
Machined Surface Quality ◽  
Machined Surfaces

The single point diamond turning process has been used extensively for direct optical surface fabrication. However, the diamond machined surfaces have characteristic periodic tool marks, which contribute to reduced optical performance such as scattering and distortion. In this paper, studies of the characteristics of diamond machined surface and scattering from the diamond machined surfaces are presented. Four different parameters, the first order optical diffraction, the zero order reflection, the surface roughness, and the residual tool mark depth, are used as indicators for the machined surface quality. Four sets of tests are presented showing the relationship between machined surface quality and machining conditions such as spindle speed, feedrate, and machining process. Finally, an empirical model is given based on the measurements.

scholarly journals Ultra-Precision Single-Point Diamond Turning of a Complex Sinusoidal Mesh Surface Using Machining Accuracy Active Control

2021 ◽  
Vol 67 (7-8) ◽  
pp. 343-351
Author(s):  
Peixing Ning ◽  
Ji Zhao ◽  
Shijun Ji ◽  
Jingjin Li ◽  
Handa Dai
Keyword(s):  
Active Control ◽  
Tool Path ◽  
Single Point ◽  
Diamond Turning ◽  
Machining Accuracy ◽  
Machining Error ◽  
Machined Surface ◽  
Mesh Surface ◽  
Slow Tool Servo ◽  
Radius Compensation

Single-point diamond turning (SPDT) assisted with slow tool servo (STS) is the most commonly utilized technique in the fabrication of optical modules. However, the tool path significantly affects the quality of the machined surface. In order to realize the determined machining accuracy effectively, a tool path generation (TPG) method based on machining accuracy active control (MAAC) is presented. The relationship between tool path and machining error is studied. Corner radius compensation (CRC) and the calculation of chord error and residual error are detailed. Finally, the effectiveness of the proposed approach is verified through a machining error simulation and a cutting experiment of a complex sinusoidal mesh surface fabrication.

Freeform machining of ophthalmic toric lens mould using fast tool servo-assisted ultra-precision diamond turning process

2020 ◽  
pp. 251659842093974
Author(s):  
Ishan Anand Singh ◽  
Gopi Krishna S. ◽  
T. Narendra Reddy ◽  
Prakash Vinod
Keyword(s):  
Surface Roughness ◽  
Single Point ◽  
Measurement Data ◽  
Surface Profile ◽  
Diamond Turning ◽  
Fast Tool Servo ◽  
Toric Surface ◽  
Machined Surface ◽  
Ultra Precision ◽  
A Minor

This research aims to establish a methodology for machining of toric lenses, using fast tool servo-assisted single point diamond turning and to assess the generated surface for its characteristics. Using the established mathematical model, toric surface is explained to understand the geometry and to generate the parameters required for fast tool servo machining. A toric surface with a major diameter of 18.93 mm and a minor diameter of 15.12 mm has been cut on the intelligent ultra-precision turning machine (iUPTM). The surface profile and surface roughness were measured. After analysing the measurement data of the machined surface, on two perpendicular axes of the toric lens, form accuracy of 0.49 µm peak-to-valley (PV), and surface roughness of 12 nm in Ra, 4–8 nm in Sa are obtained. From the experimental results obtained, it can be concluded that the proposed method is a reasonable alternative for manufacturing toric lens mould.

scholarly journals Machinability and Surface Generation of Pd40Ni10Cu30P20 Bulk Metallic Glass in Single-Point Diamond Turning

Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 4 ◽  
Author(s):  
Jie Xiong ◽  
Hao Wang ◽  
Guoqing Zhang ◽  
Yanbing Chen ◽  
Jiang Ma ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Tool Path ◽  
Single Point ◽  
Chip Morphology ◽  
Diamond Turning ◽  
Surface Generation ◽  
Workpiece Material ◽  
Machined Surface

Pd40Ni10Cu30P20 bulk metallic glass (BMG) is widely used in industrial fields due to its excellent oxidation resistance, corrosion resistance, and thermal stability. However, the lack of research on the machinability and cutting performance of BMG using single-point diamond turning (SPDT) limits its application for engineering manufacturing. In the present research, a series of turning experiments were carried out under different cutting parameters, and the machinability reflected by the quality of machined surface, chip morphology, and tool wear were analyzed. Based on the oxidation phenomenon of the machined surface, a molecular dynamics (MD) simulation was conducted to study the mechanism and suppression of the machined surface oxidation during the cutting. The results show that: (1) The Pd-based BMG had good machinability, where the machined surface roughness could go down to 3 nm; (2) irregular micro/nanostructures were found along the tool path on the outer circular region of the machined surface, which greatly affected the surface roughness; and (3) the cutting heat softened the workpiece material and flattened the tool marks under surface tension, which improved the surface quality. This research provides important theoretical and technical support for the application of BMG in optical mold manufacturing.

Analysis of the Swelling Effect in Single-Point Diamond Turning

2011 ◽  
Vol 314-316 ◽  
pp. 984-987
Author(s):  
Qing Liang Zhao ◽  
Jun Yun Chen ◽  
Jian Luo
Keyword(s):  
Surface Roughness ◽  
Material Property ◽  
Single Point ◽  
Diamond Turning ◽  
Surface Generation ◽  
Ductile Material ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Tool Mark ◽  
Material Swelling

The swelling effect is an important factor to affect surface generation in SPDT. Face cutting experiments are conducted for copper, aluminum alloy and electroless nickel phosphorus to analyze the swelling effect including the relationship between it and cutting parameters as well as effect of material property. How the material swelling affects surface roughness is also studied in this paper. The results indicate that the swelling effect is influenced by spindle speed and material property more remarkably when compared to feed rate and depth of cut. In addition, a softer and more ductile material will lead to a stronger material recovery, a lower swelling proportion, a lower tool mark height and a smoother machined surface. The result reveals that the swelling effect must be considered when predicting surface roughness in SPDT

An Experimental Study of the Formation of Tool Marks Made by Facet Diamond Cutting Tools in Single-Point Diamond Turning

2007 ◽  
Vol 364-366 ◽  
pp. 544-549
Author(s):  
Ming Chu Kong ◽  
Wing Bun Lee ◽  
Chi Fai Cheung ◽  
Suet To
Keyword(s):  
Single Point ◽  
Cutting Tools ◽  
Electroless Nickel ◽  
Diamond Turning ◽  
Diamond Cutting ◽  
Machined Surface ◽  
Fundamental Study ◽  
Tool Marks ◽  
Tool Mark ◽  
Diamond Cutting Tools

The formation of tool marks in single-point diamond turning is a fundamental study of the effect of materials swelling and recovery on surface roughness on a machined surface. A series of orthogonal face cutting tests has been conducted among plate aluminum alloy, oxygen-free high conductivity copper and electroless nickel phosphorus under the same cutting conditions by the use of facet tools with different front clearance angles. The results show that the regular width of the undulating pattern in tool marks could be explained by side swelling and the micro-waviness within a tool mark is caused by burnishing and recovery.

Brittle to Ductile Transition Dependence upon the Transition Pressure Value of Semiconductors in Micromachining

2000 ◽  
Vol 15 (8) ◽  
pp. 1688-1692 ◽  
Author(s):  
Renato G. Jasinevicius ◽  
Paulo S. Pizani ◽  
Jaime G. Duduch
Keyword(s):  
Single Crystals ◽  
Single Point ◽  
Diamond Turning ◽  
Transition Pressure ◽  
Brittle To Ductile Transition ◽  
Semiconductor Crystals ◽  
Brittle Mode

Single-point diamond turning tests were carried out in two different [001]-oriented semiconductors, InSb and Si single crystals. The analysis of the conditions in which the machining is in ductile or brittle mode indicates that the plasticity presented by semiconductor crystals during micromachining can be correlated to the value of the transition pressure. It is shown that the ductility presented by different semiconductor single crystals is inversely related to the transition pressure value of the material.

scholarly journals Influence of Lubricant Environment on Machined Surface Quality in Single-Point Diamond Turning of Ferrous Metal

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1110
Author(s):  
Menghua Zhou ◽  
Jianpeng Wang ◽  
Guoqing Zhang
Keyword(s):  
Surface Morphology ◽  
Cutting Force ◽  
Surface Quality ◽  
Single Point ◽  
Ferrous Metal ◽  
Minimum Quantity Lubrication ◽  
Diamond Turning ◽  
Machined Surface ◽  
Hard Particles ◽  
Machined Surface Quality

In the field of single-point diamond turning (SPDT), machining ferrous metal is an important research topic with promising application. For SPDT of ferrous metal, the influence of lubricant on the workpiece surface morphology remains to be studied. In this study, three lubricant machining environments were selected to carry out specific control experiments. The machined surface morphology and cutting force in different lubricant machining environments were analyzed. The experiment results showed that the lubricant environment will have significant impacts on the quality of the machined surface morphology of ferrous metal. In the environment of minimum quantity lubrication machining (MQLM-oil), better machined surface quality can be obtained than that in ordinary dry machining (ODM) and high-pressure gas machining (HGM). Furthermore, the cutting force captured in the ODM and HGM environment increased with the increase of the cutting depth, while the cutting force in the MQLM-oil environment remained almost unchanged. That indicates MQLM-oil can suppress the formation of hard particles to improve the machining quality.

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