Machining of Fused Silica Using Pulsed Laser Heating Assistance

2018 ◽  
Author(s):  
Huawei Song ◽  
Junfeng Xiao ◽  
Jialun Li ◽  
Jinqi Dan ◽  
Xiao Chen ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Material Removal ◽  
Cutting Tool ◽  
Local Heating ◽  
Fused Silica ◽  
Material Removal Mechanism ◽  
Machined Surface ◽  
Lower Tool ◽  
Pulsed Laser Heating ◽  
Conventional Machining

Fused silica is difficult to machine through conventional machining, mainly due to its high brittleness and strength, low fracture toughness and poor plastic deformation. This study was attempted to explore the machinability of fused silica with laser-assisted machining by heating workpiece through a pulse CO2 laser beam. During the LAM of fused silica, the bonding and wavelike texture on the machined surface indicated the behavior change of material deformation by the local heating in front of the cutting tool. The semi-continuous chips were obtained as an evidence of material removal mechanism which was a hybrid of quasi plastic deformation and brittle fracture. Moreover, the machinability of fused silica was evaluated. The experimental results demonstrated that considerable improvement in the machinability of fused silica was achieved such as better surface roughness, smaller cutting force as well as lower tool wear.

scholarly journals Comparative Study of Chip Formation in Orthogonal and Oblique Slow-Rate Machining of EN 16MnCr5 Steel

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 698 ◽  
Author(s):  
Monkova ◽  
Monka ◽  
Sekerakova ◽  
Hruzik ◽  
Burecek ◽  
...  
Keyword(s):  
Chip Formation ◽  
Slow Rate ◽  
Material Removal ◽  
Cutting Tool ◽  
Tool Geometry ◽  
Formation Mechanisms ◽  
Machined Surface ◽  
Thermal Influence ◽  
Microstructure Of Material ◽  
Made In

In today’s unmanned productions systems, it is very important that the manufacturing processes are carried out efficiently and smoothly. Therefore, controlling chip formation becomes an essential issue to be dealt with. It can be said that the material removal from a workpiece using machining is based on the degradation of material cohesion made in a controlled manner. The aim of the study was to understand the chip formation mechanisms that can, during uncontrolled processes, result in the formation and propagation of microcracks on the machined surface and, as such, cause failure of a component during its operation. This article addresses some aspects of chip formation in the orthogonal and oblique slow-rate machining of EN 16MnCr5 steel. In order to avoid chip root deformation and its thermal influence on sample acquisition, that could cause the changes in the microstructure of material, a new reliable method for sample acquisition has been developed in this research. The results of the experiments have been statistically processed. The obtained dependencies have uncovered how the cutting tool geometry and cutting conditions influence a chip shape, temperature in cutting area, or microhardness according to Vickers in the area of shear angle.

Investigation into Chemo-Mechanical Fixed Abrasive Polishing of Fused Silica with the Assistance of Ultrasonic Vibration

2012 ◽  
Vol 523-524 ◽  
pp. 155-160 ◽  
Author(s):  
Ya Guo Li ◽  
Yong Bo Wu ◽  
Li Bo Zhou ◽  
Hui Ru Guo ◽  
Jian Guo Cao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Vibration ◽  
Material Removal Rate ◽  
Material Removal ◽  
Optical Glass ◽  
Removal Rate ◽  
Fused Silica ◽  
Processing Efficiency ◽  
Machined Surface ◽  
Fixed Abrasive

Ultrasonic vibration assisted processing is well known for the improvement in machined surface quality and processing efficiency due to the reduced forces and tribology-generated heating when grinding hard-brittle materials. We transplanted this philosophy to chemo-mechanical fixed abrasive polishing of optical glass, namely fused silica, in an attempt to improve surface roughness and/or material removal rate. Experiments were conducted to elucidate the fundamental characteristics of chemo-mechanical fixed abrasive polishing of fused silica in the presence and absence of ultrasonic vibration on a setup with an in-house built gadget. The experimental results show that ultrasonic vibration assisted chemo-mechanical fixed abrasive polishing can yield increased material removal rate while maintaining the surface roughness of manufactured optics compared to conventional fixed abrasive polishing without ultrasonic vibration. The mechanism of material removal in fixed abrasive polishing was also delved. We found that the glass material is removed through the synergic effects of chemical and mechanical actions between abrasives and glass and the resultant grinding swarf contains ample Si element as well as Ce element, standing in stark contrast to the polisher that contains abundant Ce element and minor Si element.

Finite Element Investigation of Cutting Performance of Cr/W-DLC/DLC Composite Coated Cutting Tool

2021 ◽  
Author(s):  
Tianmei Hao ◽  
Jin Du ◽  
Xue Zhang ◽  
Guosheng Su ◽  
Peirong Zhang ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Cutting Force ◽  
Cutting Tool ◽  
Cutting Temperature ◽  
Cutting Performance ◽  
Interface Temperature ◽  
Machined Surface ◽  
Heat Partition ◽  
Coated Tools ◽  
Cutting Deformation

Abstract Coupled with a thermo-mechanical metal cutting process, rapid tool wear, higher surface roughness and mass heat are caused by the rapid plastic deformation of the workpiece and by the friction along the tool-chip interface. This phenomenon is more predominant in the machining of difficult-to-cut materials. DLC film has been applied as coating material in the machining of difficult-to-cut materials, and shows a good cutting performance. In this study, Cr/W-DLC/DLC coated tools were compared with other three coated tools (i.e., TiC-, TiAlN-, Al 2 O 3 -) to investigate the cutting performance in the machining of Al-Si alloy (AC9B). In addition, the influence of Cr/W-DLC/DLC coated tools on the cutting performance under different cutting speeds was studied. Cutting force, cutting temperature, heat transfer coefficient of the rake face of the tool, cutting deformation rate, plastic deformation of machined surface, the interface temperature and stress were investigated numerically based on Finite Element Method (FEM). Actual cutting experiments were carried out to the verification of the FEM models by means of the cutting force and cutting temperature measurement. The investigation results showed that Cr/W-DLC/DLC coated tools has the lowest cutting force and cutting temperature, good cutting deformation characteristics and lower coating-substrate interface temperature and stress, however appears the maximum value of heat partition coefficient into the cutting tool. With the increasing of cutting speeds, cutting force and cutting temperature showed an increase trend, while the plastic deformation depth of machined surface and heat partition into cutting tool all showed a decrease trend. This investigation can provide the theory basis or technical guidance for the cutting practice of Cr/W-DLC/DLC coated tools.

Machinability and Material Removal Mechanism of Face Centred Cubic (FCC) Conductive Ceramic TiBCN in EDM Processing

2016 ◽  
Vol 680 ◽  
pp. 147-151
Author(s):  
Jian Chuang Zhao ◽  
Jian Dong Hu ◽  
Fan You Meng ◽  
Yao Min Wang
Keyword(s):  
Material Removal ◽  
Machining Process ◽  
Pulse Interval ◽  
Material Removal Mechanism ◽  
Machined Surface ◽  
Material Removal Mechanisms ◽  
Interval Time ◽  
Removal Mechanisms ◽  
Discharge Duration

Fcc-TiBCN powder synthesized by boronizing of Ti was pressured into monolithic block by hot pressing (HP) method. Then the block material was machined by wire-cut EDM. The machinability and the material removal mechanisms were discussed of Fcc-TiBCN block in wire-cut EDM. Results show that the machinability of Fcc-TiBCN is satisfying. The discharge current has little relationship on surface roughness in the range of factory-adjusted optimum settings. The discharge duration and pulse interval time play an important role on the quality of machined surface and EDM machining efficiency. In order to obtain excellent quality of the machined surface, the number of power tube turned on can not exceed 6, and the pulse interval time must be as long as possible. The mini roughness of machined surface is 0.4μm～0.6μm as the number of power tube turned on is 5, the pulse interval time and discharge duration is set in the range of 20～22μs and 65～75μm, respectively. There are three material removal mechanisms of TiBCN conductive ceramic in the EDM machining process: spalling, melting and evaporation. Spalling is the main mechanism resulted by thermal stress superposing.

scholarly journals Experimental Investigation and Optimization of Delamination Factors in the Drilling of Jute Fiber Reinforced Polymer Biocomposites with Multiple Estimators

2021 ◽  
Author(s):  
Bachir Adda ◽  
Ahmed Belaadi ◽  
Messaouda Boumaaza ◽  
Mostefa Bourchak
Keyword(s):  
Neural Networks ◽  
Experimental Investigation ◽  
Response Surface Methodology ◽  
Composite Structures ◽  
Material Removal ◽  
Cutting Tool ◽  
Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Conventional Machining ◽  
Chip Removal

Abstract Currently, the manufacture of composite structures often requires material removal operations using a cutting tool. Indeed, since biocomposites are generally materials that do not conduct electricity, electro-erosion cannot be utilized. As a result, the processes that can be used are limited to conventional machining, called chip removal machining, such as drilling. Delamination factors are widely recognized for controlling the damaged area (delamination) induced by drilling in industry. As discussed in the literature, several approaches are available to evaluate and quantify the delamination surrounding a hole. In this context, the objective of this study is to compare the three Fd evaluation methods that have been most frequently used in previous investigations. To this end, three rotational and feed speeds and three BSD tool diameters were selected (L27) for drilling 155 g/m2 density jute fabric reinforced polyester biocomposites. The response surface methodology (RSM) and artificial neural networks (ANNs) were applied to validate the results obtained experimentally as well as to predict the behavior of the structure depending on the cutting conditions.

A Study on Residual Stresses in Machined Brittle Material

2016 ◽  
Vol 1136 ◽  
pp. 509-514
Author(s):  
Pei Lum Tso ◽  
Tsung Yun Tsai
Keyword(s):  
Residual Stresses ◽  
Material Removal ◽  
Surface Defects ◽  
Fused Silica ◽  
Grinding Wheel ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Photoelastic Method ◽  
Diamond Blade ◽  
Measuring Tool

Residual stresses in fused silica induced by two machining methods, diamond blade saw cutting and GC grinding wheel grinding, are studied in this study. Photoelastic method would be applied as measuring tool analyzing the gradient of residual stresses caused by different machining condition. This sentence is strange with analyzing the chips of grinding and observation of surface defects, it is assumed that the stresses gradient differs probably cause by the different material removal mechanism.

scholarly journals Atomistic Simulation Study of Nanoparticle Effect on Nano-Cutting Mechanisms of Single-Crystalline Materials

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 265 ◽  
Author(s):  
Pengyue Zhao ◽  
Qi Zhang ◽  
Yongbo Guo ◽  
Huan Liu ◽  
Zongquan Deng
Keyword(s):  
Plastic Deformation ◽  
Surface Quality ◽  
Cutting Tool ◽  
Deformation Mechanisms ◽  
Relative Depth ◽  
Machined Surface ◽  
Workpiece Surface ◽  
Single Crystalline ◽  
Machined Surface Quality ◽  
Cutting Mechanisms

Nanoparticle (NP), as a kind of hard-to-machine component in nanofabrication processes, dramatically affects the machined surface quality in nano-cutting. However, the surface/subsurface generation and the plastic deformation mechanisms of the workpiece still remain elusive. Here, the nano-cutting of a single-crystalline copper workpiece with a single spherical embedded nanoparticle is explored using molecular dynamics (MD) simulations. Four kinds of surface/subsurface cases of nanoparticle configuration are revealed, including being removed from the workpiece surface, moving as a part of the cutting tool, being pressed into the workpiece surface, and not interacting with the cutting tool, corresponding to four kinds of relative depth ranges between the center of the nanoparticle and the cutting tool. Significantly different plastic deformation mechanisms and machined surface qualities of the machined workpiece are also observed, suggesting that the machined surface quality could be improved by adjusting the cutting depth, which results in a change of the relative depth. In addition, the nanoparticle also significantly affects the processing forces in nano-cutting, especially when the cutting tool strongly interacts with the nanoparticle edge.

An Investigation Into Non-Conventional Machining of Metal Matrix Composites

2019 ◽  
pp. 175-187
Author(s):  
Divya Zindani ◽  
Kaushik Kumar
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Material Removal ◽  
Removal Rate ◽  
Matrix Composites ◽  
Abrasive Water Jet ◽  
Machined Surface ◽  
Mechanical Erosion ◽  
Conventional Machining ◽  
Very High

One of the recently developing fields is that of non-traditional machining of particle reinforced metal matrix composites. The complexity associated with traditional machining of particle reinforced metal matrix composite is very high, and therefore, the researchers have begun to show more focus towards non-traditional machining. In the present work, the investigation has been carried out for non-traditional machining such as laser beam machining, electro-chemical machining, abrasive water jet machining, and electro-chemical discharge. Material removal rate, surface finish, and the mechanism of machining has been studied for each of the aforementioned processes. The main material removal mechanisms as has been identified are melting, mechanical erosion, vaporization, and chemical dissolution. The investigation reveals that the major reasons for the damage of the machined surface are the presence of reinforcement particles and thermal degradation.

Design of the Tool for End Electrical Discharge Milling and Mechanical Grinding Compound Machining of Engineering Ceramics

2013 ◽  
Vol 664 ◽  
pp. 806-810
Author(s):  
Ren Jie Ji ◽  
Yong Hong Liu ◽  
Chao Zheng ◽  
Fei Wang ◽  
Yan Zhen Zhang
Keyword(s):  
Tool Wear ◽  
Electrical Discharge ◽  
Material Removal ◽  
Removal Rate ◽  
Mechanical Grinding ◽  
Machined Surface ◽  
Engineering Ceramics ◽  
Sic Ceramic ◽  
Machined Surface Quality ◽  
Lower Tool

Advanced engineering ceramics have been widely used in modern industry due to their excellent physical and chemical properties. However, they are difficult to machine due to their high hardness and brittleness. End electrical discharge milling and mechanical grinding compound machining method is employed to machine SiC ceramic in this paper. The process is able to effectively machine a large surface area on SiC ceramic. Furthermore, the tool for the compound machining of SiC ceramic is designed based on the goal of the higher material removal rate, the lower tool wear, and the better machined surface quality. The results show that with the designed tool for the compound machining, the higher material removal rate, the lower tool wear, and the better machined surface quality can be obtained.

Laser-Assisted Machining of Advanced Materials

2014 ◽  
Vol 800-801 ◽  
pp. 825-831 ◽  
Author(s):  
Xian Jun Kong ◽  
Hong Zhi Zhang ◽  
Xue Feng Wu ◽  
Yang Wang
Keyword(s):  
Material Removal ◽  
Cutting Tool ◽  
Advanced Materials ◽  
Material Removal Mechanism ◽  
Machine Material ◽  
High Productivity ◽  
Laser Assisted Machining ◽  
Cutting Energy ◽  
Tool Edge ◽  
Rapid Temperature

Laser-assisted machining (LAM) is a hybrid cutting process in which a laser beam is used to heat and soften the workpiece locally in front of the cutting tool edge. The rapid temperature rise at the shear zone reduces the yield strength and work hardening of the workpiece, which makes the plastic deformation of difficult-to-machine materials easier during machining. LAM provides a reduction in the cutting forces/specific cutting energy, longer tool life, better surface integrity, and high productivity over traditional cutting. This paper presents the technical characteristics, material removal mechanism and the application of machining hard-to-machine material in LAM. The latest development of LAM and future scope are summarized in this paper.

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