scholarly journals Acoustic Emission and Surface Roughness in Ultra-Precision Diamond Turning of RSA 6061 for Optics Applications

2021 ◽  
Vol 9 (2) ◽  
pp. 11-20
Author(s):  
Odedeyi Peter Babatunde ◽  
Abou-El-Hossein Khaled ◽  
Abdulkadir Lukman
Keyword(s):  
Surface Roughness ◽  
Acoustic Emission ◽  
Diamond Turning ◽  
Ultra Precision

Study, analysis, and characterization of ultra-precision diamond tools for single-point diamond turning

2020 ◽  
pp. 251659842096533
Author(s):  
RamaGopal V. Sarepaka ◽  
Sivasakthi Balan ◽  
Somaiah Doodala ◽  
Rakesh Singh Panwar ◽  
D. Rajendra Kotaria
Keyword(s):  
Surface Roughness ◽  
Diamond Tool ◽  
Single Point ◽  
Quality Parameters ◽  
Diamond Turning ◽  
Radius Of Curvature ◽  
Tool Selection ◽  
Diamond Tools ◽  
Surface Irregularities ◽  
Ultra Precision

In multiple applications of advanced instrumentation, single-point diamond turning (SPDT) is a popular and effective process to generate novel surfaces with nanometric surface roughness and sub-micron surface irregularities, albeit at a high cost. In SPDT, precision diamond tooling contributes significantly to the process cost escalation. Hence, for SPDT, it is vital to have an optimal precision diamond tool deployment. In this article, details of comprehensive precision diamond tool selection and tool characterization are discussed. Three makes of selected ultra-precision diamond (UPD) tools and standard diamond tools (of a global make), designated as CFT, are considered for this study. In this tool bench-marking exercise, the fabrication of Cu–Be alloy predesigned precision components (PDPCs) of a critical geometry is selected. UPD and CFT tools are deployed to fabricate (under similar machining-metrology conditions) the PDPCs. These diamond tools are evaluated in terms of the quality parameters (variation in radius of curvature, form error, and surface roughness) of the workpieces. Further, to explore the progressive wear of these tools, multiple machining cycles are conducted on these workpieces, and their quality parameters are analyzed. Thus, the precision diamond tools of three makes are benchmarked against the CFT tool. Based on the final outcome of this analysis, suitable recommendations are provided to precision diamond tool manufacturers to improve their product in terms of performance and optimized costs to meet the ever-growing tooling demands of the SPDT community.

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.

Ultra-Precision Turning Technology of Gold Cone in Fast Ignition

2013 ◽  
Vol 562-565 ◽  
pp. 147-151
Author(s):  
Guo Li ◽  
Yan Hua Huang ◽  
Wei Chao Tong ◽  
Guang Hui Yuan ◽  
Yang Tao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wall Thickness ◽  
Single Point ◽  
Fast Ignition ◽  
Diamond Turning ◽  
End Effect ◽  
Processing Parameter ◽  
Ultra Precision ◽  
Cone Surface

Fast Ignition (FI) attracts much attention owing to its advantages. The fabrication of fast ignition targets is one of the key technologies in FI study. Based on the single point diamond turning (SPDT) technology, Diamond post-turning method is adopted in this paper for the fabrication of gold cone. It not only helps to reduce the end-effect of cone mandrel and consequently improve the coaxiality of internal and external cone surface, but also helps to improve the quality of cone surface and the wall thickness consistency. Besides, the processing parameter of diamond post-turning is experimentally studied in this paper for its effect on the cone surface roughness. According to results, the cone surface roughness is Ra 9.21nm, the wall thickness consistency is 3μm and the cone end surface roughness is Ra5.72nm。

Effects of the Tool Angles on the Machined Surface Quality of KDP Crystal in Diamond Turning

2007 ◽  
Vol 364-366 ◽  
pp. 297-301 ◽  
Author(s):  
Jing He Wang ◽  
Ming Jun Chen ◽  
Shen Dong ◽  
Shi Qian Wang
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Rake Angle ◽  
Diamond Turning ◽  
Precision Machining ◽  
Machined Surface ◽  
Kdp Crystal ◽  
Factors Affecting ◽  
Ultra Precision ◽  
Back Angle

In the ultra-precision machining of KDP crystal, there are many factors affecting the surface quality[1-3]. The experiments show that the rake angle and back angle of the tool have significant effects on machined surface roughness. Therefore, an efficient way to improve the surface roughness is to select a proper negative rake angle. In this study, the ANSYS static analysis method was employed to analyze the stress field distribution within the whole cutting region. A finite element simulation model was set up to calculate the residual stresses variation with tool’s angles, which can be considered to select optimal rake and back angles in the ultra-precision machining of KDP crystal. Results show that the optimal tool rake angle and back angle are -49° and 7°, respectively. Finally, by using different tool angles to process KDP crystal and utilizing AFM to analyze the surface roughness, it can be found that the measurement results agree well with what are deduced from theoretical calculation.

A Study of Factors Affecting Surface Quality in Ultra-Precision Raster Milling

2007 ◽  
Vol 339 ◽  
pp. 400-406 ◽  
Author(s):  
M.N. Cheng ◽  
Chi Fai Cheung ◽  
Wing Bun Lee ◽  
Sandy To
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Dynamic Characteristics ◽  
Diamond Turning ◽  
Factors Affecting ◽  
Cutting Geometry ◽  
Milled Surface ◽  
Ultra Precision ◽  
Process Factors

Ultra-precision raster milling is an emerging manufacturing technology for the fabrication of high precision and high quality components with a surface roughness of less than 10 nm and a form error of less than 0.2 μm without the need for any subsequent post polishing. Surface quality of a raster milled surface is affected by process factors and material factors, respectively. The process factors involve cutting conditions, cutting strategies, and relative vibration between the tool and the workpiece which are related to the cutting geometry and the dynamic characteristics of the cutting process. The material factors considered are material property and swelling of the work materials. Due to different cutting mechanics, the process factors affecting the surface quality are more complicated, as compared with ultra-precision diamond turning, such as swing distance and step distance. This paper presents an experimental investigation of the distinctive process factors affecting the surface roughness in ultra-precision multi-axis raster milling. Experimental results indicate that the influence due to the process factors can be minimized through a proper selection of operational settings and better control of dynamic characteristics of the machine.

Influences of Turning Parameters on Surface Roughness in Ultra-Precision Diamond Turning Processing Technology

2014 ◽  
Vol 978 ◽  
pp. 52-55
Author(s):  
Kong Lian Xu ◽  
Zan Wu Tan
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Magnetic Field Intensity ◽  
Orthogonal Experiment ◽  
Diamond Turning ◽  
Processing Technology ◽  
Depth Of Cut ◽  
Finishing Process ◽  
Ultra Precision ◽  
The Magnetic Field

Complex surfaces can be manufactured by using ultra-precision diamond turning processing technology, whereas the surface roughness of the workpiece is influenced by many factors, the relationships among these factors are very complex, and little research reports are found. In this paper, influences of the turning parameters on surface roughness are investigated and analyzed under different related parameters such as spindle speed, feed rate and depth of cut. The result shows that the slotted tool could obtain better surface roughness than the non-slotted tool under the same conditions. Through changing the magnetic field intensity, finishing gap, rotational speed of tool and finishing time, an orthogonal experiment is conducted to obtain the optimal finishing process parameters.

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