Grinding Characteristics, Material Removal, and Damage Formation Mechanisms of Zirconia Ceramics in Hybrid Laser/Grinding

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Sheng Xu ◽  
Zhenqiang Yao ◽  
Jiawei He ◽  
Jian Xu
Keyword(s):  
Material Removal ◽  
Continuous Wave ◽  
Grinding Force ◽  
Formation Mechanisms ◽  
Continuous Wave Laser ◽  
Zirconia Ceramics ◽  
Energy Material ◽  
Ductile Mode ◽  
Conventional Grinding ◽  
Brittle Mode

Zirconia ceramics which are sometimes called “ceramic steel” have gained significant interest because of their excellent properties. However, it is desired to maintain the surface quality while increasing the economics of ceramics grinding process. A hybrid laser/grinding (HLG) process was utilized to grind zirconia ceramics which was irradiated with continuous wave laser before grinding in the hybrid process. The feasibility of hybrid laser/grinding of zirconia ceramics was investigated in terms of grinding force and energy, material removal, and damage formation mechanisms. The results show that laser irradiation can induce lateral cracks, which can help material removal and prevent further crack propagating into the base. The results of grinding tests indicate that grinding force and energy decrease significantly as compared with conventional grinding of ceramics. The combinations of the fractured area, the plowing striations, and seldom debris on the ground surfaces in this work indicate the combined material removal mechanism of both brittle mode and ductile mode.

scholarly journals Improved Erosion Resistance by HVOF Sprayed 10%Al2O3-COCrAlTaY Coating on Ti-31

2020 ◽  
Vol 8 (5) ◽  
pp. 1605-1610 ◽  
Keyword(s):  
Solid Particle ◽  
Material Removal ◽  
Research Work ◽  
Solid Particle Erosion ◽  
Particle Erosion ◽  
Air Jet ◽  
Ductile Mode ◽  
Erosion Test ◽  
Impact Angles ◽  
Brittle Mode

In this present research work the solid particle erosion test carried on uncoated samples (Ti-31), and HVOF sprayed 10%Al2O3 -CoCrAlTaY on Ti-31 are made. Erosion test are done with impact angles of 30º, 60º and 90º. Solid particle erosion studies were carried out using air jet erosion test rig as per ASTM G76-02 standard.All the three angles of uncoated alloys exhibit erosion damage under ductile mode and less amount of erosive loss compared HVOF coated samples. The HVOF sprayed coated Ti-31 at various impact angles is brittle mode. The mechanism of material removal during erosion of brittle materials is explained by using SEM micrographs.

Evaporative material removal process with a continuous wave laser

1995 ◽  
Vol 57 (4) ◽  
pp. 663-671 ◽  
Author(s):  
P. Majumdar ◽  
Z.H. Chen ◽  
M.J. Kim
Keyword(s):  
Material Removal ◽  
Continuous Wave ◽  
Continuous Wave Laser ◽  
Removal Process ◽  
Wave Laser

Machining Force and Modes for Si Wafer Machining with Rotational Tool

2010 ◽  
Vol 126-128 ◽  
pp. 289-294
Author(s):  
Nobumasa Yokemura ◽  
Kenichiro Imai ◽  
Hiroshi Hashimoto
Keyword(s):  
Material Removal ◽  
Cutting Edge ◽  
Depth Of Cut ◽  
Removal Process ◽  
Machining Force ◽  
Ductile Mode ◽  
Basic Experiments ◽  
Brittle Mode ◽  
Si Wafer

In this study, basic experiments involving machining using a rotational tool were conducted with the aim of increasing the volume of material removed rate in ductile-mode machining of Si wafers. The machining surface and machining force was compared to experimentally clarify the material removal process for a single cutting edge, the critical cutting thickness tc at which occurs of cracks was set as the machining condition. Then, the three machining modes were experimentally revealed. As the result, the ductile-mode machining surface was obtained that the total depth of cut was under less than 78.5μm on ductile-brittle-mode machining.

Fundamentals of BK7 Glass Removal in Micro/Nano-Machining

2009 ◽  
Vol 76-78 ◽  
pp. 485-490 ◽  
Author(s):  
Ming Chen ◽  
Qing Long An ◽  
Wei Min Lin ◽  
Hitoshi Ohmori
Keyword(s):  
Material Removal ◽  
Cutting Tools ◽  
Depth Of Cut ◽  
Process Technology ◽  
Ductile Mode ◽  
Fundamental Understanding ◽  
Bk7 Glass ◽  
Ductile Mode Cutting ◽  
Brittle Material Removal ◽  
Brittle Mode

The confine of ductile-mode cutting and brittle-mode cutting seems to be a crucial step for designing a brittle material removal process. However, the existing transition from ductile-mode to brittle-mode for BK7 material makes the confine of different mode very difficult. Through a series of micro/nano-machining tests, measurements of cutting forces and morphological appearance of cutting groove as well as the cross section at the certain depth of cut, the confirmation of ductile-mode cutting, transition-mode cutting and brittle-mode cutting has been clearly described in the paper. This lays a foundation for the fundamental understanding of cutting physics concerning of material characteristics and cutting tools, and thereafter for the development of optimal process technology.

Precision Grinding and Slicing of Glass-Like-Carbon

2007 ◽  
Vol 24-25 ◽  
pp. 65-70
Author(s):  
Y. Hasuda ◽  
Y. Suzuki ◽  
T. Kato ◽  
R. Meguriya ◽  
T. Furusawa ◽  
...  
Keyword(s):  
Material Removal ◽  
Mesh Size ◽  
Surface Grinding ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
New Materials ◽  
Precision Grinding ◽  
Ductile Mode ◽  
Hard Disk Substrate ◽  
Brittle Mode

High density and isotropic poreless structure of Glass-like-carbon makes it practically used for fuel cells of space-shuttles and hard disk substrate etc. Glass-like-carbon is one of the new materials which attract attention, but it is so hard and brittle that precise machining of this material is difficult. Surface grinding and slicing were performed to collect the fundamental data of precise machining. The main results obtained in this study are as follows. (1) The transition from brittle mode to ductile mode in surface grinding occurs at a grain mesh size between #5000 and #3000. (2) The maximum grain depth of cut ‘dg’ necessary for ductile mode grinding is 0.021-0.006 mm or less. (3) When it is being sliced, the kerf width of the #1000 grinding wheel becomes wider than that of the #2000 grinding wheel because of the fact that the material removal capability of the #1000 grinding wheel is bigger than that of the #2000 grinding wheel. (4) It is extremely effective to use the fine grinding wheel, since the Young's modulus of glass-like-carbon is considerably low and eventually causes compression transformation,.

scholarly journals Investigation on the Effect of Dynamic Fracture Toughness to Zirconia Ceramic Grinding Performance with Different Grain Sizes

2021 ◽  
Author(s):  
Can Yan ◽  
Zhaohui Deng ◽  
Tao Xia ◽  
Wei Liu ◽  
Hua Zhang
Keyword(s):  
Fracture Toughness ◽  
Dynamic Fracture ◽  
Material Removal ◽  
Dynamic Fracture Toughness ◽  
Grinding Force ◽  
Subsurface Damage ◽  
Material Removal Mechanism ◽  
Zirconia Ceramics ◽  
Grain Sizes ◽  
Damage Depth

Abstract To reveal the material removal mechanism of zirconia ceramics, an improved prediction models of the critical grinding force and maximum subsurface damage depth models are developed based on the dynamic fracture toughness. The effects of three different grain sizes on the material removal mechanism during brittle- ductile transition process of zirconia ceramics is analyzed through grinding experiments. And the influence of grain size on grinding force, workpiece surface roughness, surface fragmentation rate and subsurface damage depth in grinding are discussed. The results of the experiment results indicated that the value of dynamic fracture toughness tends to decrease with an increase in equivalent grinding thickness, and the ductile removal range of zirconia ceramics expands for the reason that the critical grinding force considering dynamic fracture toughness is higher than the static grinding force considering static fracture toughness, and the maximum subsurface damage depth is closer to actual maximum subsurface damage depth. Besides the smaller the grain size of zirconia ceramics, the higher the surface quality of grinding.

Research on Fractal Characterization in Grinding of Monocrystal Sapphire

2014 ◽  
Vol 800-801 ◽  
pp. 186-190
Author(s):  
Qiu Yan Wang ◽  
Wen Xiang Zhao ◽  
Zhi Qiang Liang ◽  
Xi Bin Wang ◽  
Li Jiao ◽  
...  
Keyword(s):  
Material Removal ◽  
Ground Surface ◽  
Surface Characteristics ◽  
Fractal Method ◽  
Box Counting ◽  
Fractal Properties ◽  
Ductile Mode ◽  
Parallel Direction ◽  
Material Removal Mode ◽  
Brittle Mode

Monocrystal sapphire ground surfaces obtained by ductile mode and brittle mode are analyzed in this paper. A two dimension (2D) fractal properties of different ground surfaces are calculated and analyzed by a box-counting fractal method. The results show that the fractal dimension (FD) in parallel grinding direction can imply the material removal mode, especially for the surfaces with a similar roughness Ra obtained in different material removal modes. The ground surface obtained in ductile mode has much higher FD in the parallel direction than that in brittle mode. For the surface with high FD in parallel direction, its profile is more exquisite and surface quality is better. For the surface with a small FD in the parallel direction, a deeper crack and more pronounced defects occur. On the other hand, the profile FD distributions can reflect the anisotropic features of monocrystal sapphire ground surfaces. Therefore, the fractal analysis method has the potential to reveal precisely and comprehensively the ground surface characteristics of monocrystal sapphire.

1848: Revolix 70 Watt 2 Micron Continuous Wave Laser Vaporesection of the Prostate. Preliminary Results After a One Year Follow-Up

2007 ◽  
Vol 177 (4S) ◽  
pp. 614-614
Author(s):  
Thorsten Bach ◽  
Thomas R.W. Herrmann ◽  
Roman Ganzer ◽  
Andreas J. Gross
Keyword(s):  
Continuous Wave ◽  
Continuous Wave Laser ◽  
Preliminary Results ◽  
Wave Laser ◽  
One Year

scholarly journals Thermo-responsive polymer encapsulated gold nanorods for single continuous wave laser-induced photodynamic/photothermal tumour therapy

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Beilei Gong ◽  
Yuanbing Shen ◽  
Huiyan Li ◽  
Xiaojun Li ◽  
Xia Huan ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Biomedical Applications ◽  
Continuous Wave ◽  
Continuous Wave Laser ◽  
Tumour Site ◽  
Polymer Shell ◽  
Potential System ◽  
Responsive Polymer ◽  
Good Biocompatibility ◽  
Spr Effect

AbstractOwing to strong and tunable surface plasmon resonance (SPR) effect and good biocompatibility, gold nanoparticles have been suggested to be a versatile platform for a broad range of biomedical applications. In this study, a new nanoplatform of thermo-responsive polymer encapsulated gold nanorods incorporating indocyanine green (ICG) was designed to couple the photothermal properties of gold nanorods (AuNRs) and the photodynamic properties of ICG to enhance the photodynamic/photothermal combination therapy (PDT/PTT). In addition to the significantly increased payload and enhancing photostability of ICG, the polymer shell in the nanoplatform also has thermo-responsive characteristics that can control the release of drugs at tumour sites upon the laser irradiation. On the basis of these improvements, the nanoplatform strongly increased drug aggregation at the tumour site and improved the photothermal/photodynamic therapeutic efficacy. These results suggest that this nanoplatform would be a great potential system for tumour imaging and antitumour therapy.

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