Study of surface quality and subsurface damage of germanium optics produced by single point diamond nanomachining

2019 ◽  
Author(s):  
Zdenko Zápražný ◽  
Dušan Korytár ◽  
Matej Jergel ◽  
Yuriy Halahovets ◽  
Igor Matko ◽  
...  
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Subsurface Damage

Single Point Diamond Turning Effects on Surface Quality and Subsurface Damage in Ceramics

2009 ◽  
Author(s):  
Deepak Ravindra ◽  
John A. Patten ◽  
Jun Qu
Keyword(s):  
Raman Spectroscopy ◽  
Optical Microscopy ◽  
Surface Quality ◽  
Material Removal ◽  
Single Point ◽  
Subsurface Damage ◽  
Diamond Turning ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
Machining Parameters

Advanced ceramics, such as Silicon Carbide (SiC) and Quartz, are increasingly being used for industrial applications. These ceramics are hard, strong, inert, and light weight. This combination of properties makes them ideal candidates for tribological, semiconductor, MEMS and optoelectronic applications respectively. Manufacturing these materials without causing surface and subsurface damage is extremely challenging due to their high hardness, brittle characteristics and poor machinability. Often times, severe fracture can result when trying to achieve high material removal rates during machining of SiC or quartz due to their low fracture toughness. This research demonstrates that ductile regime Single Point Diamond Turning (SPDT) is possible on these materials to improve its surface quality without imparting subsurface damage. Machining parameters, such as depth of cut and feed, used to carry out ductile regime machining will be discussed. Subsurface damage analysis was carried out on the machined samples using non-destructive methods such as Optical Microscopy, Raman Spectroscopy and Scanning Acoustic Microscopy to show evidence that the chosen material removal method leaves a damage-free surface and subsurface. Optical microscopy was used to image the improvements in surface finish whereas Raman spectroscopy and scanning acoustic microscopy was used to observe the formation of amorphous layer and subsurface imaging in the machined regions. All three techniques complement the initial hypothesis of being able to remove a nominally brittle material in the ductile regime.

scholarly journals ANALYSIS OF THE SURFACE QUALITY OF PARTS PROCESSED BY SINGLE POINT INCREMENTAL FORMING

2016 ◽  
Vol 19 (3) ◽  
Author(s):  
CRINA RADU ◽  
EUGEN HERGHELEGIU ◽  
ION CRISTEA ◽  
CAROL SCHNAKOVSZKY
Keyword(s):  
Surface Quality ◽  
Process Parameters ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Metal Sheets ◽  
Vertical Step ◽  
Tool Diameter ◽  
Aluminium Metal

<p>The aim of the current work was to analyse the influence of the process parameters (tool diameter, size of the vertical step of tool, feed rate and spindle speed) on the quality of the processed surface, expressed in terms of roughness and macrostructure in the case of parts processed by single point incremental forming. The analysis was made on A1050 aluminium metal sheets. The obtained results revealed that the process parameters influence differently the surface quality, the worst influence being exerted by the increase of the vertical step of tool. </p>

scholarly journals Research on the Influencing Factors of "Scale Veins" of Single Point Incremental Forming Workpieces Surface

2015 ◽  
Vol 9 (1) ◽  
pp. 1025-1032
Author(s):  
Shi Pengtao ◽  
Li Yan ◽  
Yang Mingshun ◽  
Yao Zimeng
Keyword(s):  
Surface Quality ◽  
Incremental Forming ◽  
Single Point ◽  
Spindle Speed ◽  
Experimental Results ◽  
Feed Speed ◽  
Single Point Incremental Forming ◽  
Machining Parameters ◽  
The Mathematical Model

To furthermore optimize the machining parameters and improve the surface quality of the workpieces manufactured by single point incremental forming method, the formation mechanism of the sacle veins on the metal incremental froming workpieces was studied through experiment method. The influence principle of the spindle speed, the feed speed and the material of tip of tools on the length of scale veins was obtained through analyzing the experimental results and building the mathematical model among the length of scale veins were feed speed and spindle speed through measuring the roughness of surfaces and observing the appearance of the forming workpieces. The experimental results showed that, the spindle speed, the feed speed and the material of tool tips have a significant effect on the scale veins formation on the surface of forming workpieces. Therefore, an appropriate group of spindle speed and feed speed can reduce the effect of scale veins on the roughness of single point incremental forming workpieces and furthermore improve the surface quality of forming workpieces.

Subsurface damage in alumina induced by single-point scratching

1996 ◽  
Vol 31 (4) ◽  
pp. 905-914 ◽  
Author(s):  
I. Zarudi ◽  
L. Zhang ◽  
Y. -W. Mai
Keyword(s):  
Single Point ◽  
Subsurface Damage

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.

A Study of Cutting Strategy in Single-Point Diamond Turning of Micro V-Groove Patterns on Precision Roller Drums

2014 ◽  
Vol 625 ◽  
pp. 742-747
Author(s):  
C.H. Mak ◽  
C.F. Cheung ◽  
M.J. Ren ◽  
L.B. Kong ◽  
S. To
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Cutting Parameters ◽  
Diamond Turning ◽  
Surface Generation ◽  
Depth Of Cut ◽  
Tool Paths ◽  
Cutting Strategy ◽  
Groove Pattern

This paper presents a study of cutting strategies on the surface generation in single-point diamond turning of micro V-groove patterns on precision roller drums. An aluminium precision roller drum with a diameter 250mm and 100 long was diamond turned with a V-groove pattern. A series of cutting experiments were designed to study the effect of the variation of various cutting parameters and cutting tool paths on the surface quality in diamond turning of the precision roller drum. The parameters under investigation included the depth of cut, number of steps and the depth for each cut when diamond turning V-grooves on the cylindrical surface of a workpiece. The measurement result indicates that the surface quality of V-grooves machined on the precision roller drums is affected by cutting strategies. The optimal cutting strategy for machining a V-groove pattern on a precision drum with 5µm depth was obtained.

scholarly journals A Novel Tool to Enhance The Lubricant Efficiency On Induction Heat-Assisted Incremental Sheet Forming of Ti-6Al-4V Sheets

2022 ◽  
Author(s):  
Weining Li ◽  
Khamis Essa ◽  
Sheng Li
Keyword(s):  
Surface Quality ◽  
Single Point ◽  
Water Channel ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Water Cooling ◽  
Geometric Accuracy ◽  
Molybdenum Disulphide ◽  
Roughness Analysis ◽  
Pass Through

Abstract For heat-assisted single point incremental sheet forming (SPIF) works of Ti-6Al-4V sheets, the use of lubricant has shown significant effects on surface quality and geometric accuracy at higher temperatures. Molybdenum disulphide (MoS2) is a common lubricant widely used in SPIF works, however, it usually indicates ineffective performance at high temperatures. This article has studied different lubricants of MoS2 lubricants and proposed a novel mixture of MoS2 to provide better surface quality and improve geometric accuracy. A forming tool with a ball-roller and water channel was designed to enable the MoS2 mixture to pass through the tool tip, allowing easy application of the lubricant on the localised area and reduce the thermal expansion on the ball-roller. Surface roughness analysis has revealed that the water-cooling MoS2 mixture performed well in reducing friction effects and achieved better geometric accuracy. Forming forces measurements, scanning electron microscope (SEM), energy dispersive X-ray Analysis (EDX) and micro-hardness tests also indicated that a higher strain hardening behaviour was detected for the water-cooling MoS2 mixture.

Research on Subsurface Damage of Lapping Sapphire with Diamond Fixed Abrasive

2020 ◽  
Vol 866 ◽  
pp. 143-151
Author(s):  
Jian Bin Wang ◽  
Yong Qiang Tong ◽  
Ben Chi Jiang ◽  
Da Shu ◽  
Gang Wang
Keyword(s):  
Surface Quality ◽  
Surface Damage ◽  
Subsurface Damage ◽  
Indentation Fracture ◽  
Damage Layer ◽  
Damage Depth ◽  
The Difference ◽  
Fixed Abrasive ◽  
Free Abrasive

The depth of surface/subsurface damage layer is the key index of surface quality of sapphire. In this paper, that depth model of the surface/subsurface damage lay characterized by the crack length was established according to the mechanical theory of indentation fracture. The cutting relation between abrasive and workpiece and the difference of the depth of subsurface damage crack are analyzed. It is preliminarily estimated that the length of sub-surface damage crack of free abrasive sapphire is about 2.46 times that of fixed abrasive when considering only the contact hardness of abrasive grain under static load. Diamond abrasives with size of W20 were adopted to carry out experiments in free and fixed lapping methods. The results show that the surface/subsurface damage depth is 9.87μm and 3.63μm respectively. It is easier to obtain good sub-surface quality by using the fixed abrasive method than free abrasive at the same particle size.

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