High Efficiency Precision Surface Grinding of Fused Silica

High efficiency and high surface integrity grinding of fused silica lens used in the ultraviolet (UV) laser transmission equipments is highly demanded. It is necessary to decrease the undeformed chip thickness for producing better surface integrity. We conducted creep feed grinding (CFG) and conventional shallow cut grinding (SCG) experiments of fused silica with a resin bond diamond wheel. Experiment results shows that owing to thinner undeformed chip thickness, the normal grinding force, radial wheel wear and P-V value of surface roughness of CFG are smaller than those of SCG at the same MRR. At the same table speed, surface roughness decreased with the increase of MRR in both CFG and SCG as a result of decreased undeformed chip thickness which is attributed to the elasticity of resin bond.

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Ductile and Brittle Mode Grinding of Fused Silica

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.447-448.21 ◽

2010 ◽

Vol 447-448 ◽

pp. 21-25 ◽

Cited By ~ 9

Author(s):

Peng Yao ◽

Nobuhito Yoshihara ◽

Nobuteru Hitomi ◽

Ji Wang Yan ◽

Tsunemoto Kuriyagawa

Keyword(s):

Surface Integrity ◽

High Efficiency ◽

High Surface ◽

Ground Surface ◽

Fused Silica ◽

Wheel Speed ◽

Depth Of Cut ◽

Creep Feed ◽

Ductile Mode ◽

Brittle Mode

There is a demand for high-efficiency and high surface integrity grinding of fused silica. Ductile grinding is an ideal method for producing a mirror finished surface on hard and brittle materials to significantly decrease polishing time. However, the fused silica is still difficult to ductile grind because of its high brittleness. A creep feed taper grinding method was applied to investigate the relationship between maximum grit depth of cut and surface integrity of fused silica. Ductile mode grinding was achieved on fused silica. When the depth of cut exceeds the critical wheel depth of cut, the surface suddenly changes from the ductile mode to the brittle mode. At the same ratio of wheel speed and table speed, the critical wheel depth of cut is noticeably increased by increasing the wheel speed which caused an increase in the temperature at the interface of grains and workpiece. The depth of subsurface damage (SSD) was investigated by polishing the ground surface. The experiment results show that the depth of SSD is deepest in transition mode and stables in brittle mode.

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Wheel Wear Related Instability in Grinding of Quartz Glass

10.21203/rs.3.rs-424350/v1 ◽

2021 ◽

Author(s):

Yonghao Wang ◽

Ping Zhou ◽

Yuhang Pan ◽

Ying Yan ◽

Dongming Guo

Keyword(s):

Surface Roughness ◽

Surface Quality ◽

Chip Thickness ◽

Ground Surface ◽

Grinding Force ◽

Grinding Wheel ◽

Wheel Wear ◽

Undeformed Chip Thickness ◽

Grinding Wheel Wear ◽

Ground Surface Roughness

Abstract Grinding is a popular method for producing high-quality parts made of hard and brittle materials. A lot of researchers have focused on the impact of grinding parameters on surface quality. However, only a few studies discussed the surface quality instability caused by the grinding wheel wear during a long grinding process. In this paper, through wheel state monitoring and surface quality testing of ground samples, it is found that the relationship between ground surface roughness and theoretical undeformed chip thickness is significantly affected by the grinding wheel wear state, rather than maintain steady as described in most available models. By introducing the normal grinding force, a linearly relationship was found among normal grinding force, undeformed chip thickness and ground surface roughness. Besides, sensitivity analysis was conducted to guide the parameter adjustment to maintain the stability of ground surface roughness and grinding state. The mechanism of the effect of wheel wear on normal grinding force was also studied in detail. This study will help to further understand the mechanism of the influence of wheel wear on the grinding stability.

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Effect of Optical and Morphological Control of Single-Structured LEC Device

Micromachines ◽

10.3390/mi12070843 ◽

2021 ◽

Vol 12 (7) ◽

pp. 843

Author(s):

Woo Jin Jeong ◽

Jong Ik Lee ◽

Hee Jung Kwak ◽

Jae Min Jeon ◽

Dong Yeol Shin ◽

...

Keyword(s):

Heat Treatment ◽

Surface Roughness ◽

Surface Properties ◽

High Efficiency ◽

High Surface ◽

Reduction Rate ◽

Operating Characteristics ◽

Emission Layer ◽

Light Emitting ◽

Stable Operating

We investigated the performance of single-structured light-emitting electrochemical cell (LEC) devices with Ru(bpy)3(PF6)2 polymer composite as an emission layer by controlling thickness and heat treatment. When the thickness was smaller than 120–150 nm, the device performance decreased because of the low optical properties and non-dense surface properties. On the other hand, when the thickness was over than 150 nm, the device had too high surface roughness, resulting in high-efficiency roll-off and poor device stability. With 150 nm thickness, the absorbance increased, and the surface roughness was low and dense, resulting in increased device characteristics and better stability. The heat treatment effect further improved the surface properties, thus improving the device characteristics. In particular, the external quantum efficiency (EQE) reduction rate was shallow at 100 °C, which indicates that the LEC device has stable operating characteristics. The LEC device exhibited a maximum luminance of 3532 cd/m2 and an EQE of 1.14% under 150 nm thickness and 100 °C heat treatment.

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Surface and Sub-Surface Integrity of Ultra- Machined BK7 Using Fine and Coarse Grained Diamond Wheels

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.359-360.234 ◽

2007 ◽

Vol 359-360 ◽

pp. 234-238 ◽

Cited By ~ 4

Author(s):

Qing Liang Zhao ◽

Bo Wang ◽

Ekkard Brinksmeier ◽

Otmann Riemer ◽

Kai Rickens ◽

...

Keyword(s):

Surface Roughness ◽

Surface Integrity ◽

High Surface ◽

Coarse Grained ◽

Nanometer Scale ◽

Grinding Wheels ◽

Fine Grained ◽

Optical Glasses ◽

Diamond Grinding ◽

Surface Damages

This paper aims to evaluate the surface and sub-surface integrity of optical glasses which were correspondingly machined by coarse and fine-grained diamond grinding wheels on Tetraform ‘C’ and Nanotech 500FG. The experimental results show that coarse-grained diamond grinding wheels are capable of ductile grinding of optical glasses with high surface and sub-surface integrity. The surface roughness values are all in nanometer scale and the sub-surface damages are around several micros in depth, which is comparative to those machined by fine-grained diamond wheels.

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An Investigation about the Effect of Depth of Cut on Surface Integrity in Creep Feed Grinding of INC 792-5A

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.320.163 ◽

2011 ◽

Vol 320 ◽

pp. 163-169

Author(s):

R. Ashofteh ◽

A. Rastkerdar ◽

S. Kolahdouz ◽

A. Daneshi

Keyword(s):

Surface Roughness ◽

Surface Integrity ◽

Structural Changes ◽

Depth Of Cut ◽

Machining Parameters ◽

Cutting Depth ◽

Creep Feed Grinding ◽

Creep Feed ◽

Micro Cracks ◽

Average Grain Size

Creep-Feed Grinding(CFG) is one of the none-traditional machining in which form grinding to full depth is performed in limited number of passes. One of the most significant criteria which is taken into account to display valid machining parameters, is surface integrity. Surface integrity in CFG process is influenced by four main factors including surface roughness, superficial micro-crack, burning and changes in micro-hardness. According to prior investigations in CFG process, depth of cut plays an important role in surface integrity. In this study, the influence of cutting depth on workpiece surface integrity of cast nickel-based superalloy with alummina wheels, was investigated. During this study, a sample part was machined with variable depth of cut while the other parameters were Constant. After machining, surface roughness of each specimen was measured and in order to investigate existence and dimensional situation of surface micro-cracks, Chemical Etch + FPI and Thermal shock + FPI were performed. For determining micro-structural changes in ground specimens as a clarifier criteria in measuring the level of residual stress, a set of recrystallization processes were carried out on them and average grain size were measured. The results show, however, changing in depth of cut hasn't influenced on micro-cracks, quality of surface roughness has descended in terms of increasing the cutting depth.

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Growth of Atomic Layer Deposited Ruthenium and Its Optical Properties at Short Wavelengths Using Ru(EtCp)2 and Oxygen

Coatings ◽

10.3390/coatings8110413 ◽

2018 ◽

Vol 8 (11) ◽

pp. 413 ◽

Cited By ~ 1

Author(s):

Robert Müller ◽

Lilit Ghazaryan ◽

Paul Schenk ◽

Sabrina Wolleb ◽

Vivek Beladiya ◽

...

Keyword(s):

Thin Films ◽

Surface Roughness ◽

Optical Properties ◽

Deposition Temperature ◽

Film Growth ◽

High Surface ◽

Atomic Layer ◽

Fused Silica ◽

High Density ◽

Adhesion Properties

High-density ruthenium (Ru) thin films were deposited using Ru(EtCp)2 (bis(ethylcyclopentadienyl)ruthenium) and oxygen by thermal atomic layer deposition (ALD) and compared to magnetron sputtered (MS) Ru coatings. The ALD Ru film growth and surface roughness show a significant temperature dependence. At temperatures below 200 °C, no deposition was observed on silicon and fused silica substrates. With increasing deposition temperature, the nucleation of Ru starts and leads eventually to fully closed, polycrystalline coatings. The formation of blisters starts at temperatures above 275 °C because of poor adhesion properties, which results in a high surface roughness. The optimum deposition temperature is 250 °C in our tool and leads to rather smooth film surfaces, with roughness values of approximately 3 nm. The ALD Ru thin films have similar morphology compared with MS coatings, e.g., hexagonal polycrystalline structure and high density. Discrepancies of the optical properties can be explained by the higher roughness of ALD films compared to MS coatings. To use ALD Ru for optical applications at short wavelengths (λ = 2–50 nm), further improvement of their film quality is required.

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Experimental Study on Grinding of a Nickel-Based Alloy Using Vitrified CBN Wheels

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.325.134 ◽

2011 ◽

Vol 325 ◽

pp. 134-139 ◽

Cited By ~ 3

Author(s):

Zhong De Shi ◽

Amr Elfizy ◽

Benoit St-Pierre ◽

Helmi Attia

Keyword(s):

Experimental Study ◽

Surface Roughness ◽

Material Removal ◽

Removal Rate ◽

Wheel Wear ◽

Creep Feed ◽

Nickel Based Alloy ◽

Specific Material ◽

Grinding Power ◽

Vitrified Cbn

An experimental study is reported on the grinding of a nickel-based alloy using vitrified CBN wheels. This work was motivated by switching the grinding of fir-tree root forms of jet engine blades from creep-feed grinding with conventional abrasive wheels to vitrified CBN wheels. The objective is to explore process limits and practical grinding parameters for judging the switch in terms of overall costs and productivity. Straight surface grinding experiments were conducted with water-based fluid on rectangular blocks at a fixed wheel speed vs = 45 m/s, various depths of cut a = 0.05 - 1.0 mm, and workspeeds vw = 2 - 40 mm/s. Grinding power, forces, surface roughness, and radial wheel wear were measured. Specific material removal rate of 8 mm3/(mm.s) was reached in rough grinding using a wheel dressed for achieving surface roughness Ra = 0.8 µm in finish grinding. It was found that shallow depths of cut combined with fast workspeeds, or less creep-feed modes, are more suitable for achieving high material removal rates with vitrified CBN grinding. Rough grinding is restricted by high grinding temperatures with newly dressed wheels and by chatters with worn wheels.

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Experimental Investigations of Cutting Parameters Influence on Cutting Forces and Surface Roughness of Quartz Glass

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.641-642.367 ◽

2013 ◽

Vol 641-642 ◽

pp. 367-370

Author(s):

Gui Qiang Liang ◽

Fei Fei Zhao

Keyword(s):

Surface Roughness ◽

Cutting Force ◽

Cutting Forces ◽

Cutting Speed ◽

Chip Thickness ◽

Cutting Parameters ◽

Diamond Wheel ◽

Experimental Investigations ◽

Depth Of Cut ◽

Feed Force

Abstract In the present study, an attempt has been made to investigate the effect of cutting parameters (cutting speed, feed rate and depth of cut) on cutting forces (feed force, thrust force and cutting force) and surface roughness in milling of Quartz glas using diamond wheel. The cutting process in the up-cut milling of glass is discussed and the cutting force measured. The cutting force gradually increases with the cutter rotation at the beginning of the cut, and oscillates about a constant mean value after a certain undeformed chip thickness. The results show that cutting forces and surface roughness do not vary much with experimental cutting speed in the range of 55–93 m/min. The suggested models of cutting forces and surface roughness and adequately map within the limits of the cutting parameters considered.

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