Chemically Assisted Machining of Ceramics

1994 ◽  
Vol 116 (3) ◽  
pp. 423-429 ◽  
Author(s):  
J. C. Wang ◽  
S. M. Hsu
Keyword(s):  
Material Removal ◽  
Removal Rate ◽  
High Hardness ◽  
Chemical Compounds ◽  
Surface Damage ◽  
Diamond Wheel ◽  
Halogenated Hydrocarbons ◽  
Ceramic Machining ◽  
Machining Of Ceramics ◽  
Machining Fluids

Ceramics are hard and brittle. Machining such materials is time-consuming, difficult, and expensive. Current machining technology requires stiff machine, high hardness tools, and small material removal rates to minimize surface damage. This study demonstrates the feasibility of a novel ceramic machining concept that utilizes chemical reactions at the tool-workpiece interface to reduce the stress and minimize the surface damage. A series of cutting tests using a diamond wheel on silicon nitride with different chemical compounds has been performed. The results demonstrate that by using different chemistries, the material removal rate and the surface finish of the machined ceramic can be significantly altered. Some halogenated hydrocarbons show a significant improvement over some commercial machining fluids currently in use.

Optimization of Coated SiC Belt Grinding of Alumina Ceramics

2009 ◽  
Vol 76-78 ◽  
pp. 38-42 ◽  
Author(s):  
Xavier Kennedy ◽  
S. Gowri
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
High Hardness ◽  
Surface Damage ◽  
High Temperature Strength ◽  
Structural Ceramics ◽  
Alumina Ceramics ◽  
Belt Grinding ◽  
Grinding Parameters ◽  
Surface Damages

Advanced structural ceramics have been increasingly used in automotive, aerospace, military, medical and other applications due to their high temperature strength, low density, thermal and chemical stability. However, the Grinding of advanced ceramics such as alumina is difficult due to its low fracture toughness and sensitivity to cracking, high hardness and brittleness. In this paper, surface integrity and material removal mechanisms of Alumina ceramics ground with SiC abrasive belts, have been investigated. The surface damage have been studied with scanning electron microscope (SEM). The significance of grinding parameters on the responses was evaluated using Signal to Noise ratios.This research links the surface roughness and surface damages to grinding parameters. The optimum levels for maximum material removal and surface roughness been discussed.

Dependence between Workpiece Material Hardness and Face Lapping Results of Steel C45

2015 ◽  
Vol 220-221 ◽  
pp. 743-748
Author(s):  
Justyna Molenda ◽  
Adam Charchalis
Keyword(s):  
High Precision ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Hardness Test ◽  
Surface Damage ◽  
Angular Speed ◽  
Workpiece Material ◽  
Abrasive Grains ◽  
Material Hardness

The high demands required today by manufacturing engineers for machine parts and tools necessitate very precise machining. The finishing processes are an important perspective to be considered today for meeting the goals like parallelism, tolerances, flatness, and smooth surface. These processes are high-precision abrasive processes used to generate surfaces of desired characteristic such as geometry, form, tolerances, surface integrity, and roughness characteristics. A leading importance in this perspective has the lapping process. It leads to a surface with low roughness and high precision. The topographical structure resulting from lapping is very advantageous in sliding joints, because of the high ability of lubricant retention, as well as in nonsliding joints because of the high load-carrying ability. Many materials can be lapped, including glass, ceramic, plastic, metals and their alloys, sintered materials, satellite, ferrite, copper, cast iron, steel, etc.This paper reports the observations of steel C45 elements lapping process results. Workpieces were rollers with diameter 17 mm and height 10 mm placed in the conditioning rings with use of workholdings. Samples were divided to three groups according to their Vicker’s hardness: 160, 440, and 650 HV. After grinding, lapping process was conducted. Experiments were carried out with an angular speed of the lapping plate set at 65 RPM, and lapping velocity was v = 49 m/min. The lapping pressure was provided by dead weights and during experiments executing p = 0.04 MPa. Samples were lapped during 10, 15 and 20 minutes. Abrasive slurry was composed of silicon carbide grains mixed with kerosene and machine oil. Abrasive grains size was F400/17.The material removal rate (MRR) and specimens surface characteristic are studied in the light of workpiece material hardness. Test results show that applied process parameters are the best for steel which hardness is 440 HV. In that case, the lowest values of Raparameter were obtained in conjunction with satisfactory values of material removal rate. It can be also seen, as could be predicted, that lapping time influenced on lapping results. MRR increases and surface roughness decreases with time. The worst lapping results were obtained for normalized steel (160HV). It can be the effect of surface damage, like scratching and grooving by harder abrasive grains.

Study on Grinding Performance of Soft Abrasive Wheel for Silicon Wafer

2009 ◽  
Vol 416 ◽  
pp. 529-534 ◽  
Author(s):  
Ren Ke Kang ◽  
Shang Gao ◽  
Zhu Ji Jin ◽  
Dong Ming Guo
Keyword(s):  
Silicon Wafer ◽  
Chemical Reaction ◽  
Removal Rate ◽  
Surface Damage ◽  
Amorphous Layer ◽  
Diamond Wheel ◽  
Wafer Surface ◽  
Abrasive Wheel ◽  
Grinding Performance ◽  
Diamond Abrasive

With the development of IC manufacturing technology, the machining precision and surface quality of silicon wafer are proposed much higher, but now the planarization techniques of silicon wafer using free abrasive and bonded abrasive have the disadvantage of poor profile accuracy, environmental pollution, deep damage layer, etc. A soft abrasive wheel combining chemical and medical effect was developed in this paper, it could get super smooth, low damage wafer surface by utilizing mechanical friction of abrasives and chemical reaction among abrasives, additives, silicon. A comparison experiment between #3000 soft abrasive wheel and #3000 diamond abrasive wheel was given to study on the grinding performance of soft abrasive wheel. The results showed that: wafer surface roughness ground by soft abrasive wheel was sub-nanometer and its sub-surface damage was only 0.01µm amorphous layer, which were much better than silicon wafer ground by diamond abrasive wheel, but material removal rate and grinding ratio of soft abrasive wheel were lower than diamond wheel. The wafer surface ground by soft abrasive wheel included Ce4+, Ce3+, Si4+, Ca2+ and Si, which indicated that the chemical reaction really occurred during grinding process.

scholarly journals Removal Characteristics of Sapphire Lapping using Composite Plates with Consciously Patterned Resinoid-Bonded Semifixed Diamond Grits

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 293 ◽  
Author(s):  
Wenshan Wang ◽  
Yiqing Yu ◽  
Zhongwei Hu ◽  
Congfu Fang ◽  
Jing Lu ◽  
...  
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Sol Gel ◽  
High Hardness ◽  
Dimensional Accuracy ◽  
Composite Plates ◽  
Thickness Variation ◽  
Total Thickness Variation ◽  
Abrasive Tools

Sapphire lapping is of key importance for the successful planarization of wafers that are widely present in electronic devices. However, the high hardness of sapphire makes it extremely challenging to improve its material removal rate during the lapping process without compromising surface quality and dimensional accuracy. In this work, a novel composite lapping plate consisting of a rigid resin frame and flexible sol–gel balls was fabricated with consciously designed patterns. Through lapping experiment, it was revealed that the diamond grits imbedded in the sol–gel balls can effectively lap the sapphire at a promising material removal rate (MRR), without the formation of undesirable scratches and loss of surface integrity. Moreover, by designing the arrangement patterns of sol–gel balls, the total thickness variation (TTV) can also be ensured for lapped sapphire substrates. The implications of experimental results were also discussed based on the trajectory analysis and contact mechanics of lapping grits in order to demonstrate the potential of the newly developed composite abrasive tools for sapphire-lapping applications.

Analysis of the Main Parameters in the Chemical Mechanical Polishing Process

2011 ◽  
Vol 317-319 ◽  
pp. 29-33 ◽  
Author(s):  
Xiang Dong Yang ◽  
Xin Wei ◽  
Xiao Zhu Xie ◽  
Zhuo Chen ◽  
Wei Bo Zou
Keyword(s):  
Surface Quality ◽  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Rotation Speed ◽  
Removal Rate ◽  
Surface Damage ◽  
Mechanical Polishing ◽  
Technological Parameters ◽  
Polishing Pressure

This paper studies the chemical mechanical polishing (CMP) of the wafer's material such as stainless steel, monocrystalline silicon etc, and analyzes how the technological parameters’ impact on the final wafer’s surface material removal rate, surface quality and surface damage like the polishing pad’s speed and the wafer speed, polishing pressure and polishing time.The results show that: when the difference between the polishing pad's rotation speed and the wafer's rotation speed is small and their directions are the same , then the material removal rate of the wafer is larger.when the polishing pressure is selected between 5 to 6.5 kPa, the wafer surface's damage is smaller.The polishing time also play a very important role and affect the surface quality and surface damage of the wafer after polishing.

The Research on the Improved CMG Tool for Al2O3 Ceramic

2011 ◽  
Vol 121-126 ◽  
pp. 514-518
Author(s):  
Heng Zhen Dai ◽  
Zhu Ji Jin ◽  
Shang Gao ◽  
Zhan Chun Tao ◽  
Feng Wei Huo
Keyword(s):  
Material Removal ◽  
High Efficiency ◽  
Removal Rate ◽  
Surface Damage ◽  
Ceramic Specimen ◽  
Al2o3 Ceramic ◽  
Mechanical Removal ◽  
Ultra Precision ◽  
Ceramic Process ◽  
Diamond Abrasive

A new D/SiO2 CMG tool for Al2O3 ceramic process was developed by adding some diamond abrasive into SiO2 CMG tool. The solid state reaction between the CMG tool and Al2O3 ceramic played a key role for achieving ultra-precision, high efficiency and low damage.Three kinds of formulations for the D/SiO2 tool were tested and evaluated. The material removal rate(MRR) of Al2O3 ceramic mainly depended on the content of diamond abrasive. In contrast with the corresponding SiO2 tool,the D/ SiO2 tool, which had minimal content of diamond abrasive,could achieve a minimal Ra and better MRR. The enhanced mechanical removal action made the MRR improve nearly twice times, and the process surface roughness of Al2O3 ceramic specimen using the D/ SiO2 tool kept almost same value as using the SiO2 tool without surface damage. Thus the D/ SiO2 tool is more suitable for process of Al2O3 ceramic workpieces.

Two Dimensional Ultrasonic Vibration Assisted Chemo-Mechanical Grinding of Si Wafer

2010 ◽  
Vol 126-128 ◽  
pp. 282-288
Author(s):  
Zhen Zhong Wang ◽  
Yong Bo Wu ◽  
Li Bo Zhou ◽  
Yin Biao Guo ◽  
Chen Xu Wu
Keyword(s):  
Ultrasonic Vibration ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Damage ◽  
Vibration Modes ◽  
Two Dimensional ◽  
Mechanical Grinding ◽  
Grinding Method ◽  
Fixed Abrasive ◽  
Si Wafer

As a new fixed-abrasive machining method, chemo-mechanical grinding (CMG) is developed from chemical mechanical polishing (CMP), with the obvious advantage of geometric accuracy determinacy and no slurry. To improve material removal rate and enhance the popularity of CMG, this paper introduces a combined grinding method, i.e., two dimensional ultrasonic vibration assisted CMG (2D-UACMG). Si wafer is taken as the workpiece and the influence of ultrasonic vibration modes and process parameters on the surface roughness and the material removal is examined. The results show 2D-UACMG can obtain better surface quality with little surface damage at nanometer level compared with the conventional CMG without the ultrasonic vibration.

Dressing of Monolayer Brazed Diamond Wheel for Grinding Li-Ti Ferrite

2010 ◽  
Vol 126-128 ◽  
pp. 995-1000 ◽  
Author(s):  
Hong Hua Su ◽  
Yu Can Fu ◽  
Jiu Hua Xu ◽  
Wen Feng Ding ◽  
Hong Jun Xu
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Removal Rate ◽  
Ground Surface ◽  
Diamond Wheel ◽  
Substantial Improvement ◽  
Precision Grinding ◽  
High Roughness ◽  
Grinding Operations ◽  
Ground Surface Roughness

The monolayer brazed diamond tools have recently been used increasingly in hard-brittle materials grinding because of their excellent grinding performances as long tool life, high material removal rate and large inter-grit chip space, etc. However, they possess an inherent shortcoming of the high roughness of the grinding surface. This work is an attempt to reduce the over-protruded grits of the monolayer brazed diamond wheel so that precision grinding operations can be executed effectively. In this investigation, the monolayer brazed diamond wheels with regular distribution pattern of grit have been dressed by a special conditioning process and used in precision grinding experiments on Li-Ti ferrite. The outcome of this attempt appeared highly encouraging. A substantial improvement of the ground surface roughness could be achieved with the dressed monolayer brazed diamond wheels.

scholarly journals The Methodologies Adopted To Improve the Machinability in Die-Sinking EDM

2019 ◽  
Vol 9 (1S4) ◽  
pp. 645-647
Keyword(s):  
Tool Wear ◽  
Material Removal Rate ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
High Surface ◽  
High Hardness ◽  
Machining Process ◽  
Work Piece ◽  
Machining Processes

Electrical discharge machining (EDM) is one of the oldest nontraditional machining processes, commonly used in automotive, aerospace and ship building industries for machining metals that have high hardness, strength and to make complicated shapes that cannot be produced by traditional machining techniques. The process is based on the thermoelectric energy between the work piece and an electrode. EDM is slow compared to conventional machining, low material removal rate, high surface roughness, high tool wear and formation of recast layer are the main disadvantages of the process. Tool wear rate, material removal rate and surface quality are important performance measures in electric discharge machining process. Numbers of ways are explored by researchers for improving and optimizing the output responses of EDM process. The paper summarizes the research on die-sinking EDM relating to the improvements in the output response.

Electro Discharge Machining of AL2O3 Based Ceramic

2014 ◽  
Vol 625 ◽  
pp. 511-517
Author(s):  
S.K. Elmenshawy ◽  
Mohammad A. Younes ◽  
Hassan El-Hofy
Keyword(s):  
Performance Measures ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
High Hardness ◽  
Crater Diameter ◽  
Average Roughness ◽  
Electro Discharge Machining ◽  
Complex Shapes ◽  
Pulse On Time

Products such as parts of die sets and cutting tool inserts are normally produced with complex shapes in materials of high hardness and wear resistance such as ceramics. Electro discharge machining (EDM) can be used to manufacture complex shapes in high hardness materials, but the material should be conductive. Being conductive, Aluminum oxide (Al2O3) based ceramics represent a good alternative for manufacturing hard complex shape parts. However, the integrity of the produced surfaces and the material removal rate need to be investigated. A full factorial experimental design was used to investigate the effect of some selected process variables, namely; pulse-on time, pulse-off time, and pulse current on specific EDM performance measures. The considered performance measures are; crater diameter (D), material removal rate (MRR), and average roughness value (Ra). An analysis of variance (ANOVA) test was carried out to evaluate the experimental results. Empirical models have been developed using DESIGN EXPERT V.8 to predict the average crater diameter (D), material removal rate (MMR), and average roughness value (Ra). Machining conditions that should result in optimum process performance measures have also been considered.

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