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.

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.

Prediction of Surface Quality for Silicon Carbide Wheel Grinding of Silicon Nitride

2006 ◽  
Vol 532-533 ◽  
pp. 297-300
Author(s):  
Li Ming Xu ◽  
Albert J. Shih ◽  
Bin Shen ◽  
Chun Xiang Ma ◽  
De Jin Hu
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
Silicon Nitride ◽  
Surface Quality ◽  
Prediction Accuracy ◽  
Surface Damage ◽  
Small Samples ◽  
Support Vector ◽  
Grinding Parameters ◽  
Grinding Efficiency

The experimental results for silicon carbide (SiC) wheel with fine grit size grinding of silicon carbide (Si3N4) revealed that the grinding parameters affect not only the ground silicon nitride surface roughness, but also the degree of surface damage. There exists complex non-linear relationship between the grinding parameters and surface quality. Better surface roughness doesn’t surely mean less surface damage. A method of prediction of grinding quality based on support vector regression is then presented according to the condition of small samples. The result shows the prediction accuracy based on this method is obviously higher than neural network, which provides an effective way for optimizing the grinding parameters to ensure the grinding quality as well as grinding efficiency while grinding of silicon carbide using conventional abrasive.

Laser-Assisted Machining of a Fiber Reinforced Metal Matrix Composite

2009 ◽  
Author(s):  
Chinmaya R. Dandekar ◽  
Yung C. Shin
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Metal Matrix ◽  
Material Removal ◽  
Volume Fraction ◽  
Cutting Speed ◽  
Surface Damage ◽  
Specific Cutting Energy ◽  
Cutting Energy ◽  
Multi Phase

Metal matrix composites due to their excellent properties of high specific strength, fracture resistance and corrosion resistance are highly sought after over their non-ferrous alloys, but these materials also present difficulty in machining. Excessive tool wear and high tooling costs of diamond tools makes the cost associated with machining of these composites very high. This paper is concerned with machining of high volume fraction long-fiber MMC’s, which has seldom been studied. The composite material considered for this study is an Al-2%Cu aluminum matrix composite reinforced with 62% by volume fraction alumina fibers (Al-2%Cu/Al2O3). Laser-machining is utilized to improve the tool life and the material removal rate while minimizing the sub-surface damage. The effectiveness of the laser-assisted machining process is studied by measuring the cutting forces, specific cutting energy, surface roughness, sub-surface damage and tool wear under various material removal temperatures. A multi-phase finite element model is developed in ABAQUS/Standard to identify and assist in selection of cutting parameters such as; tool rake angle, cutting speed and material removal temperature. The multi-phase model is also successful in predicting the damage depth on machining. The optimum material removal temperature is established as 300°C at a cutting speed of 30 m/min. LAM provides a 65% reduction in the surface roughness, specific cutting energy, the tool wear rate and minimum sub-surface damage over conventional machining using the same cutting conditions.

Cr12MoV Die Repair Experiment Based on Laser Cladding with Wire

2019 ◽  
Vol 814 ◽  
pp. 137-143 ◽  
Author(s):  
Yan Yin ◽  
Yun Wang ◽  
Zhong Rui Tan ◽  
Wei Jie Yu
Keyword(s):  
Surface Roughness ◽  
Laser Cladding ◽  
Light Trapping ◽  
Steel Wire ◽  
High Hardness ◽  
Scanning Speed ◽  
Surface Damage ◽  
Cladding Layer ◽  
Wire Feeding ◽  
Process Factors

In this paper, SKD11 steel wire has been deposited on Cr12MoV plate using Nd: YAG pulsed laser for repairing the die surface damage. The effects of laser power, wire feeding speed, scanning speed and surface roughness on clad geometry have been studied with OM and LSCM. hardness distribution of the cladding layer is also obtained by microhardness tester. Experiment results indicate that the surface roughness is important for clad characteristics due to the light trapping effect. With the increases of roughness, the laser absorption ratio can be raised, both the clad depth and the dilution rate increase, the height decreases. The essence of influence mechanism is effective body energy Ev and specific filling rate ω, and can be used as critical process factors. When Ev is 80~100 J/mm3 and ω is 1~3, a flat cladding layer can be obtained with low dilution, less fusion defects and high hardness. Keywords: Cr12MoV, laser cladding with wire, surface roughness, clad geometry, hardness

Research of Surface Roughness of Fluid Piston Rod Based on the Abrasive Belt Grinding

2009 ◽  
Vol 416 ◽  
pp. 187-191
Author(s):  
Zhi Ming Lv ◽  
Yun Huang ◽  
Zhi Huang ◽  
Li Na Si
Keyword(s):  
Surface Roughness ◽  
Manufacturing Process ◽  
Research Result ◽  
Grinding Process ◽  
Experiment Research ◽  
Belt Grinding ◽  
Abrasive Belt ◽  
Grinding Parameters

The method of abrasive belt finishing slender piston rod was proposed in this paper, which based on low surface roughness weaknesses of low rigidity slender piston rod in the grinding process. And the ralation between the surface roughness and the grinding parameters was analyzed by the experiment research. The research result has a reasonably guidance for the actual manufacturing process.

Material Removal Model of Lap Grinding for Sapphire Substrate Based on Roughness Parameters

2017 ◽  
Vol 890 ◽  
pp. 384-387
Author(s):  
Hyun Seop Lee ◽  
Taek Yung Lee
Keyword(s):  
Surface Roughness ◽  
Sapphire Substrate ◽  
Material Removal ◽  
High Hardness ◽  
Mechanical Polishing ◽  
Geometrical Shape ◽  
Machining Processes ◽  
Material Removal Model ◽  
Semiconductor Circuits ◽  
Mechanical Machining

Sapphire is one of difficult-to-machine materials because of its high hardness and brittleness. It can be used for an optical window or cover named as sapphire glass and a substrate for semiconductor circuits. Before preparing the required surface roughness of sapphire substrate, the geometrical shape should be retained through mechanical machining processes. The lapping and diamond mechanical polishing (DMP) are essentially used for achieving the required thickness and surface roughness of sapphire substrate prior to chemical mechanical polishing (CMP). In this study, we introduce a lap grinding process using fixed abrasives to substitute lapping and DMP. The material removal rates (MRRs) were measured under various machining conditions. The semi-empirical model on MRR was introduced based on the information of grinding pallet. This paper may provide a preliminary experimental study on the lap grinding of sapphire substrate.

Parametric Study of Pulsed CO2 Laser Surface Treatment of Alumina Ceramics

2015 ◽  
Vol 15 (3) ◽  
pp. 301-308
Author(s):  
A. Bharatish ◽  
H. N. Narasimha Murthy ◽  
Ajithkumar Radder ◽  
V. Mamatha ◽  
B. Anand ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Laser Power ◽  
Material Removal ◽  
Removal Rate ◽  
Scanning Speed ◽  
Pulse Frequency ◽  
Alumina Ceramics ◽  
Laser Surface Treatment ◽  
Grey Relational

AbstractThis paper focuses on investigating the influence of laser power, pulse frequency and scanning speed on material removal rate and surface roughness during CO2 laser surface treatment of alumina ceramics. Pulse frequency and laser power were the significant factors influencing the material removal rate and surface roughness, respectively. Adequate response surface models were established to correlate the laser parameters and the measured responses. Grey relational analysis predicted the optimal responses at 90 W laser power, 5 kHz pulse frequency and 400 mm/s scanning speed. Desirability function based Multi objective optimization results indicated that minimum material removal rate (0.5117 mm3/s) and surface roughness (0.5968 µm) are achieved at 90 W laser power, 5 kHz pulse frequency and 337.37 mm/s scanning speed which were in close agreement with Grey Relational results. Increase in homogeneity and smoothness of the laser treated alumina surface along with formation of micro recast particles away from the laser traverse path were evidenced by the SEM micrographs.

Experiment Research on ZrO2 Engineering Ceramics with Abrasive Belt Grinding

2014 ◽  
Vol 1017 ◽  
pp. 92-97 ◽  
Author(s):  
Die Zhang ◽  
Yun Huang ◽  
Xian Yin ◽  
Li Qi Zhou ◽  
Yu Hang Yang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Force ◽  
Belt Grinding ◽  
Workpiece Surface ◽  
Engineering Ceramics ◽  
Abrasive Belt ◽  
Belt Speed ◽  
Cutting Model

Abrasive belt grinding experiments of ZrO2Engineering Ceramics are carried out by using 4 different abrasive belts. The orthogonal test with zirconia-corundum belt was to get the best grinding parameter, the amount of material removal workpiece surface roughness and belt wear were measured to get the best grinding parameter.In this paper,the influence of abrasive belt granularity and different grinding parameters to grinding efficiency and workpiece surface quality throughout the process of grinding ZrO2Engineering Ceramics was analyzed. Analysis wear mechanism of engineering ceramics based on the Abrasive cutting model by observing the surface morphology. The results show that increasing the grinding force or the abrasive belt granularity can decrease the workpiece surface roughness;With the abrasive belt speed or grinding force increasing,the material removal rate and the wear ratio to some extent, but brittle fracture is occued easily on its surface when exceeds the critical value; When the abrasive belt speed is 19m/s,the grinding force is 15N and the abrasive belt granularity is 120#, ZrO2Engineering Ceramics grinding effects reach the best.

Research on the Decoating Effect and Microstructure of Surface Damage of High-Pressure Waterjet

2014 ◽  
Vol 541-542 ◽  
pp. 180-184
Author(s):  
Qi Guo ◽  
Xiu Jie Jia ◽  
Shuo Li ◽  
Yan Yan Nie ◽  
Shun Xin Ge
Keyword(s):  
Surface Roughness ◽  
High Pressure ◽  
Impact Test ◽  
Surface Damage ◽  
Water Jet ◽  
Surface Damages ◽  
Pressure Water ◽  
High Pressure Water Jet ◽  
Coated Surfaces ◽  
The Impact

The high-pressure water jet is utilized to perform impact test on coated surfaces with different hardness. The decoating effect is measured and the surface roughness change can be tested by White-light Interferometer (WLI). Also the microstructure of surface damage after impact test is analyzed. The result shows that when utilizing high-pressure water jet to clean the coating, it’s a better choice to start at the place where the coating is broken. The gap will be enlarged rapidly and the decoating velocity will increase linearly. Otherwise, the impact of water jet will cause surface damages and generate holes of particular shape. This kind of hole is flat in the middle, then forming a sunken district and apophysis successively along the radius outwards.

The Effect of Slurry Composition and Flatness on Sub-Surface Damage and Removal in Chemical Mechanical Polishing of 6H-SiC

2009 ◽  
Vol 615-617 ◽  
pp. 605-608 ◽  
Author(s):  
Gi Sub Lee ◽  
Hyun Hee Hwang ◽  
Chang Hyun Son ◽  
Jung Woo Choi ◽  
Won Jae Lee ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Removal Rate ◽  
Diamond Particle ◽  
Surface Damage ◽  
Surface Damages ◽  
The Mean ◽  
Sic Wafer ◽  
Slurry Composition ◽  
Nano Size ◽  
Evaluation Parameters

The effect of slurry composition and wafer flatness on a material removal rate (MRR) and resulting surface roughness which are evaluation parameters to determine the CMP characteristics of the on-axis 6H-SiC substrate were systematically investigated. 10 x 10 mm2 6H-SiC substrates and 2-inch SiC wafers fabricated from the ingot grown by a conventional physical vapor transport (PVT) method are used for this study. The SiC substrate after the CMP process using slurry added oxidizers into slurry consisted of KOH-based colloidal silica and nano-size diamond particle exhibited the significant MRR value and a fine surface without any surface damages. SiC wafers having high bow value after the CMP process exhibited large variation in surface roughness value compared to wafer with low bow value. The CMP-processed SiC wafer having a low bow value of 10m was observed to result in the MRR value of 0.15 m/h and the mean height (Ra) value of 0.772Ǻ.

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