Ductile and Brittle Mode Grinding of Fused Silica

2010 ◽  
Vol 447-448 ◽  
pp. 21-25 ◽  
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.

High Efficiency Precision Surface Grinding of Fused Silica

2011 ◽  
Vol 418-420 ◽  
pp. 1132-1136 ◽  
Author(s):  
Peng Yao ◽  
Ya Dong Gong ◽  
Suo Xian Yuan ◽  
Nobuhito Yoshihara ◽  
Ji Wang Yan ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
High Efficiency ◽  
High Surface ◽  
Chip Thickness ◽  
Diamond Wheel ◽  
Fused Silica ◽  
Wheel Wear ◽  
Undeformed Chip Thickness ◽  
Creep Feed

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.

Indentation Crack Initiation and Ductile to Brittle Transition Behavior of Fused Silica

2013 ◽  
Vol 797 ◽  
pp. 667-672 ◽  
Author(s):  
Peng Yao ◽  
Wei Wang ◽  
Chuan Zhen Huang ◽  
Jun Wang ◽  
Hong Tao Zhu ◽  
...  
Keyword(s):  
Penetration Depth ◽  
High Efficiency ◽  
Fused Silica ◽  
Load Range ◽  
Brittle Transition ◽  
Ductile Mode ◽  
Indentation Crack ◽  
Ultra Precision ◽  
Ductile To Brittle Transition ◽  
Brittle Mode

To provide a fundamental knowledge for the high efficiency grinding and ultra-precision grinding of fused silica, ductile mode and brittle mode material removal mechanisms were investigated by conducting micro/nanoindentation experiments in the range of 4.9 mN - 1960 mN. Before observing cracks and determining the ductile to brittle transition penetration depth, the samples were etched with hydrofluoric acid to expose cracks. The typical damage morphology of fused silica was discussed by observing the surface and cross-section of indentations, and the depth of SSD was found to be determined by the cone cracks or borderline cracks in the different load range. The ductile to brittle transition penetration depth of fused silica under Vickers indentation was 180 nm.

Study on Edge Contact Area and Surface Integrity of Workpiece in Point Grinding Process

2009 ◽  
Vol 407-408 ◽  
pp. 577-581
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
High Speed ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Edge Contact ◽  
Cylindrical Grinding ◽  
Theoretic Foundations

During cylindrical grinding process, the geometric configuration and size of the edge contact area between the grinding wheel and workpiece have the heavy effects on the workpiece surface integrity. In consideration of the differences between the point grinding and the conventional high speed cylindrical grinding, the geometric and mathematic models of the edge contact area in point grinding were established. Based on the models, the numerical simulation for the edge contact area was performed. By means of the point grinding experiment, the effect mechanism of the edge contact area on the ground surface integrity was investigated. These will offer the applied theoretic foundations for optimizing the point grinding angles, depth of cut, wheel and workpiece speed, geometrical configuration and size of CBN wheel and some other grinding parameters in point grinding process.

Temperature Measurement of Workpieces in Conventional Surface Grinding

1998 ◽  
Vol 122 (2) ◽  
pp. 297-303 ◽  
Author(s):  
T. Kato ◽  
Hiroshi Fujii
Keyword(s):  
Thin Film ◽  
Ground Surface ◽  
Wheel Speed ◽  
Surface Grinding ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
Thermal Sensor ◽  
Moving Heat Source ◽  
Pvd Film ◽  
Film Method

Temperature at various depths from the ground surface in workpiece is measured accurately by using the newly developed PVD film method, in which a thin film deposited on the workpiece is used as a thermal sensor. The influence of workpiece speed, depth of cut and wheel speed on the temperature of the workpiece was investigated under conventional surface grinding with no grinding fluids. The measured results were compared with Takazawa’s approximation based on Jaeger’s heat conduction solution to the moving heat source problem. The maximum temperature rise at the surface and the temperature gradient close to the surface were obtained and correlated with the residual stress induced at the surface. [S1087-1357(00)70302-9]

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

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.

The Process Experimental Study on High Efficiency Deep Grinding for 9SiCr Alloy Steel with a CBN Wheel

2013 ◽  
Vol 457-458 ◽  
pp. 172-176
Author(s):  
Zong Fu Guo ◽  
Xiao Min Sheng ◽  
Gui Zhi Xie ◽  
De Zhen Yin ◽  
Wen Xin Li
Keyword(s):  
Surface Quality ◽  
Alloy Steel ◽  
High Efficiency ◽  
Removal Rate ◽  
Grinding Force ◽  
Wheel Speed ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Good Surface ◽  
High Removal Rate

This paper via investigate the process of 9SiCr alloy steel in high efficiency deep grinding to find the rule between grinding wheel speed vs depth of cut ap and speed of table vw with the grinding force and the surface quality. Intend to develop a suitable method of the grinding process of 9SiCr alloy steel in high efficiency deep grinding, to obtain high removal rate and good surface quality.

Effects of abrasive type cooling mode and peripheral grinding wheel speed on the AISI D2 steel ground surface integrity

2009 ◽  
Vol 49 (3-4) ◽  
pp. 261-272 ◽  
Author(s):  
Brahim Ben Fathallah ◽  
Nabil Ben Fredj ◽  
Habib Sidhom ◽  
Chedly Braham ◽  
Yoshio Ichida
Keyword(s):  
Surface Integrity ◽  
Ground Surface ◽  
Wheel Speed ◽  
Grinding Wheel ◽  
Cooling Mode ◽  
Aisi D2 Steel ◽  
Aisi D2 ◽  
D2 Steel

Experimental Investigation on Dry Point Grinding Process Based on Green Manufacturing

2010 ◽  
Vol 431-432 ◽  
pp. 470-473
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
Point Contact ◽  
Ground Surface ◽  
Green Manufacturing ◽  
Depth Of Cut ◽  
Grinding Process ◽  
Cooling Conditions ◽  
Dry Grinding ◽  
Grinding Power

Due to point contact cause, the point grinding process have the lower grinding power and heat to measure and the better cooling conditions. For green manufacturing, the point grinding process has the significance to reduce the consumption of grinding fluid and improve the ground surface integrity and the process greenness. This study analyzes the geometric configuration of the contact area between the wheel and the workpiece in point grinding process, establishes the geometric and mathematic models of the contact area, and investigates the relations between the grinding parameters. The dry point grinding experiments are performed on the ground surface integrity. These investigations show that the dry grinding can be achieved in point grinding process under less depth of cut and the higher grinding speed for the high machining greenness demand.

Analysis of Microstructure of Grinding Strengthening Layer in Point Grinding under Small Depth of Cut Conditions

2012 ◽  
Vol 472-475 ◽  
pp. 974-977 ◽  
Author(s):  
Shi Chao Xiu ◽  
Ming He Liu ◽  
Jian Hen Wei
Keyword(s):  
Quality Control ◽  
Surface Integrity ◽  
Thermal Load ◽  
Theoretical Basis ◽  
Surface Hardness ◽  
Ground Surface ◽  
Working Life ◽  
Depth Of Cut ◽  
Layer Formation ◽  
Small Depth

Grinding strengthening and hardening can change and improve the ground surface integrity directly by the composite process of thermal load and mechanical force during process. The thickness and distribution of strengthening layer in ground surface makes the key role to measure the surface integrity of workpiece. The hardness and size of strengthening layer can influence the fatigue strength working life of the workpiece significantly. Based on the grinding strengthening test of 45 steel specimens, the strengthened layer microstructure, thickness and surface hardness were analyzed. This study illustrates the mechanism of grinding strengthened layer formation and also provides the theoretical basis for grinding strengthening and hardening layer quality control and grinding strengthening process making properly under small depth of cut conditions.

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