A Molecular Dynamics Simulation Study of Material Removal Mechanisms in Vibration Assisted Nano Impact-Machining by Loose Abrasives

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Sagil James ◽  
Murali Sundaram
Keyword(s):  
Material Removal ◽  
Removal Rate ◽  
Dynamics Simulation ◽  
Common Mechanism ◽  
Initial Kinetic Energy ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Material Removal Mechanisms ◽  
Removal Mechanisms ◽  
The Impact

Vibration assisted nano impact-machining by loose abrasives (VANILA) is a novel nanomachining process to perform target-specific nano abrasive machining of hard and brittle materials. In this study, molecular dynamic (MD) simulations are performed to understand the nanoscale material removal mechanisms involved in the VANILA process. The simulation results revealed that the material removal for the given impact conditions happens primarily in ductile mode through three distinct mechanisms, which are nanocutting, nanoplowing, and nanocracking. It was found that domination by any of these mechanisms over the other mechanisms during the material removal process depends on the impact conditions, such as angle of impact and the initial kinetic energy of the abrasive grain. The transition zone from nanocutting to nanoplowing is observed at angle of impact of near 60 deg, while the transition from the nanocutting and nanoplowing mechanisms to nanocracking mechanism is observed for initial abrasive kinetic energies of about 600–700 eV. In addition, occasional lip formation and material pile-up are observed in the impact zone along with amorphous phase transformation. A material removal mechanism map is constructed to illustrate the effects of the impacts conditions on the material removal mechanism. Confirmatory experimentation on silicon and borosilicate glass substrates showed that all the three nanoscale mechanisms are possible, and the nanoplowing is the most common mechanism. It was also found that the material removal rate (MRR) values are found to be highest when the material is removed through nanocracking mechanism and is found to be lowest when the material removal happens through nanocutting mechanism.

Investigation of Material Removal Mechanism in EDM of Sintered NdFeB Permanent Magnet

2007 ◽  
Vol 334-335 ◽  
pp. 937-940
Author(s):  
Li Li ◽  
Zong Wei Niu ◽  
Jian Hua Zhang
Keyword(s):  
Permanent Magnet ◽  
Material Removal ◽  
Thermal Cracking ◽  
Removal Mechanism ◽  
Whole Grain ◽  
Material Removal Mechanism ◽  
Ndfeb Magnet ◽  
Material Removal Mechanisms ◽  
Removal Mechanisms ◽  
Ndfeb Permanent Magnet

Sintered NdFeB permanent magnet is widely used in many applications because of its excellent magnet property. However the report of EDM research on NdFeB magnet is not available. This paper presents a detailed investigation of the material removal mechanisms of sintered NdFeB magnet through analysis of the machining debris and the surface SEM quality. It is included three types of machining mechanisms: melting and evaporating, thermal cracking, spalling or whole grain removal.

Modeling of Material Removal Mechanism in Micro Electric Discharge Milling of Ti-6Al-4V

2014 ◽  
Vol 592-594 ◽  
pp. 516-520 ◽  
Author(s):  
Basil Kuriachen ◽  
Jose Mathew
Keyword(s):  
Material Removal Rate ◽  
Feed Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Milling Process ◽  
Work Piece ◽  
Machining Parameters ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Electric Discharge Milling

Micro EDM milling process is accruing a lot of importance in micro fabrication of difficult to machine materials. Any complex shape can be generated with the help of the controlled cylindrical tool in the pre determined path. Due to the complex material removal mechanism on the tool and the work piece, a detailed parametric study is required. In this study, the influence of various process parameters on material removal mechanism is investigated. Experiments were planned as per Response Surface Methodology (RSM) – Box Behnken design and performed under different cutting conditions of gap voltage, capacitance, electrode rotation speed and feed rate. Analysis of variance (ANOVA) was employed to identify the level of importance of machining parameters on the material removal rate. Maximum material removal rate was obtained at Voltage (115V), Capacitance (0.4μF), Electrode rotational Speed (1000rpm), and Feed rate (18mm/min). In addition, a mathematical model is created to predict the material removal

Study on Chemical Mechanical Polishing Removal Mechanism of Monocrystalline Silicon

2014 ◽  
Vol 538 ◽  
pp. 40-43
Author(s):  
Hong Wei Du ◽  
Yan Ni Chen
Keyword(s):  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Silicon Wafers ◽  
Monocrystalline Silicon ◽  
Mechanical Polishing ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Polishing Pressure

In this paper, material removal mechanism of monocrystalline silicon by chemical etching with different solutions were studied to find effective oxidant and stabilizer. Material removal mechanism by mechanical loads was analyzed based on the measured acoustic signals in the scratching processes and the observation on the scratched surfaces of silicon wafers. The chemical mechanical polishing (CMP) processes of monocrystalline silicon wafers were analyzed in detail according to the observation and measurement of the polished surfaces with XRD. The results show that H2O2 is effective oxidant and KOH stabilizer. In a certain range, the higher concentration of oxidant, the higher material removal rate; the higher the polishing liquid PH value, the higher material removal rate. The polishing pressure is an important factor to obtain ultra-smooth surface without damage. Experimental results obtained silicon polishing pressure shall not exceed 42.5kPa.

Material Removal Mechanism in Vibration-Assisted Magnetic Abrasive Finishing

2008 ◽  
Vol 53-54 ◽  
pp. 57-63 ◽  
Author(s):  
Shao Hui Yin ◽  
Yu Wang ◽  
Takeo Shinmura ◽  
Yong Jian Zhu ◽  
Feng Jun Chen
Keyword(s):  
Material Removal ◽  
Removal Rate ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Magnetic Abrasive Finishing ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Vibration Assistance ◽  
Series Of Experiments ◽  
Working Distance

This paper proposed a viewpoint to explain why vibration assistance may increase material removal rate (MRR) in vibration-assisted magnetic abrasive finishing process. A series of experiments on vibration-assisted finishing have been carried out. On the basis of these experiments, the finishing characteristics are represented summarily. It was shown that the increase in material rate is mainly due to an increase in material removal per unit working distance.

Study on Chemical Mechanical Polishing Mechanism of LiTaO3 Wafer

2006 ◽  
Vol 304-305 ◽  
pp. 310-314
Author(s):  
Xin Wei ◽  
Hui Yuan ◽  
H.W. Du ◽  
Wei Xiong ◽  
Rui Wei Huang
Keyword(s):  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Acoustic Signals ◽  
Mechanical Action ◽  
Mechanical Polishing ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Mechanical Loads ◽  
Crystal Wafer

In this paper, the scratching processes by a diamond indentor under the loads linearly increased from zero were studied to assess the mechanical behavior of LiTaO3 crystal wafer. Material removal mechanism of LiTaO3 crystal by mechanical loads was analyzed based on the measured acoustic signals in the scratching processes and the observation on the scratched surfaces of LiTaO3 wafers. The chemical mechanical polishing (CMP) processes of LiTaO3 wafers were analyzed in detail according to the observation and measurement of the polished surfaces of LiTaO3 wafers with SEM and XRD. The research results show that there exist four regimes along the scratched groove with the increasing of down force in a scratching process of LiTaO3 crystal wafer, and the critical load for each regime is affected by the loading speed and final load, etc. When H2O2 and KOH are added into the polishing slurry, the material of LiTaO3 wafer is removed by chemical reaction and mechanical action sequentially in the CMP processes, and the material removal rate increases while the surface roughness is improved.

FEM Investigation of Damage Evolution at Elevated Temperatures With Multiple Impact Hits in Vibration Assisted Nano Impact Machining by Loose Abrasives

2019 ◽  
Author(s):  
Nick H. Duong ◽  
Jianfeng Ma ◽  
Shuting Lei ◽  
Murali Sundaram ◽  
Muhammad P. Jahan
Keyword(s):  
Material Removal ◽  
Elevated Temperatures ◽  
Operating Temperature ◽  
Computational Study ◽  
Frictional Coefficient ◽  
Impact Angle ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Multiple Impact ◽  
The Impact

Abstract In this paper, a computational study of a novel nanomachining process, Vibration Assisted Nano Impact machining by Loose Abrasives (VANILA), is conducted using the commercial FEM software package ABAQUS. In this novel nanomachining process, an atomic force microscope (AFM) is utilized as a platform and the nano abrasives are injected in the slurry which is located between the workpiece and the vibrating AFM probe. These nano abrasives impact the workpiece and result in nanoscale material removal. In this research, diamond particles are used as loose abrasives and the ductile mode machining is used to describe the behavior of the brittle silicon workpiece. This study aims to investigate the effects of operating temperature and number of multiple impact hits on material removal mechanism of VANILA process. The impact speed of the loose abrasives is kept constant at 200 m/s and the impact angle is fixed at 90°. The frictional coefficient during the machining is considered to be 0.05. The material removal mechanism at various operating temperatures (20°C, 100°C, 200°C, 400°C, 600°C, and 800°C) and multiple impacts are tested. It is found that the operating temperature and number of impact hits have substantial influence on material removal volume in the VANILA process.

Material Removal Mechanisms of Oxide and Nitride CMP with Ceria and Silica-Based Slurries - Analysis of Slurry Particles Pre- and Post-Dielectric CMP

2004 ◽  
Vol 816 ◽  
Author(s):  
Naga Chandrasekaran
Keyword(s):  
Material Removal ◽  
Surface Composition ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Surface Hardness ◽  
Organic Coating ◽  
Material Removal Mechanisms ◽  
Removal Mechanisms ◽  
The Difference ◽  
Oxide Removal

AbstractThe effect of CMP process parameters (pressure and pad hardness) on the ceria and silica abrasive particle-size distribution (PSD), morphology, and surface composition when polishing oxide and nitride surfaces was investigated in detail. The PSD was observed to shift post-CMP, with ceria and silica exhibiting a decrease and increase, respectively, in the number of particles towards the tail end of the distribution. The shift in ceria PSD was observed to increase as pad hardness increased. An increase in polish pressure and work surface hardness resulted in an equivalent shift in the PSD when polished on a soft pad. The inclusion of an additive reduced the oxide removal rate, and the abrasive particles exhibited the presence of a thin organic coating on the surface. The difference in material removal mechanisms and selectivity when polishing oxide and nitride with ceria and silica-based slurries was also investigated in detail.

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