Influences of Grit Shape and Cutting Edge on Material Removal Mechanism of a Single Abrasive in Flexible Robotic Grinding

2013 ◽  
Author(s):  
Amir Masoud Tahvilian ◽  
Henri Champliaud ◽  
Zhaoheng Liu ◽  
Bruce Hazel
Keyword(s):  
Material Removal Rate ◽  
Cutting Forces ◽  
Material Removal ◽  
Position Control ◽  
Removal Rate ◽  
Element Model ◽  
Rake Angle ◽  
Work Piece ◽  
Force Model ◽  
Robotic Grinding

A flexible robotic grinding system has been used for in situ maintenance of large hydro turbine runners by Hydro-Quebec. Field trials for more than 20 years have proven the reliability and efficiency of the technology for hydropower equipment maintenance and repair. This portable robot named SCOMPI, is developed by IREQ, Research Institute of Hydro-Quebec and can perform high material removal rate grinding on hardly accessible areas of turbine runner blades. Due to the light weight and low rigidity of the robot, traditional position control of conventional grinding is not applicable in this process. Instead a hybrid force/position controller is employed to ensure the accuracy of the predefined material removal rate. Therefore, having a good force model for a specific removal rate is a prerequisite for controlling the grinding task. Understanding the grinding process as the cutting action of several single grits participating in the material removal process provides an insight to predict the needed forces. This paper presents an investigation of the effects of grits shape on cutting forces in single abrasive cutting mechanism during high removal rate grinding by SCOMPI robot. A three-dimensional finite element model is developed to simulate the chip formation process with different grit shapes. Thermal results from our previous study of temperature distribution in the contact zone for this special robotic grinding are imposed to the un-deformed chips. Then, Johnson-Cook plasticity model is employed to investigate effects of hardening and thermal softening of work piece material in cutting forces. It is also found that, rake angle and cutting edges of the grit can have significant effects on the cutting and normal forces.

scholarly journals A surrogate-assisted optimization approach for multi-response end milling of aluminum alloy AA3105

2020 ◽  
Vol 111 (9-10) ◽  
pp. 2419-2439
Author(s):  
Tamal Ghosh ◽  
Yi Wang ◽  
Kristian Martinsen ◽  
Kesheng Wang
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Material Removal Rate ◽  
Cutting Forces ◽  
Material Removal ◽  
End Milling ◽  
Removal Rate ◽  
Cutting Parameters ◽  
Data Driven ◽  
Optimal Cutting Parameters

Abstract Optimization of the end milling process is a combinatorial task due to the involvement of a large number of process variables and performance characteristics. Process-specific numerical models or mathematical functions are required for the evaluation of parametric combinations in order to improve the quality of the machined parts and machining time. This problem could be categorized as the offline data-driven optimization problem. For such problems, the surrogate or predictive models are useful, which could be employed to approximate the objective functions for the optimization algorithms. This paper presents a data-driven surrogate-assisted optimizer to model the end mill cutting of aluminum alloy on a desktop milling machine. To facilitate that, material removal rate (MRR), surface roughness (Ra), and cutting forces are considered as the functions of tool diameter, spindle speed, feed rate, and depth of cut. The principal methodology is developed using a Bayesian regularized neural network (surrogate) and a beetle antennae search algorithm (optimizer) to perform the process optimization. The relationships among the process responses are studied using Kohonen’s self-organizing map. The proposed methodology is successfully compared with three different optimization techniques and shown to outperform them with improvements of 40.98% for MRR and 10.56% for Ra. The proposed surrogate-assisted optimization method is prompt and efficient in handling the offline machining data. Finally, the validation has been done using the experimental end milling cutting carried out on aluminum alloy to measure the surface roughness, material removal rate, and cutting forces using dynamometer for the optimal cutting parameters on desktop milling center. From the estimated surface roughness value of 0.4651 μm, the optimal cutting parameters have given a maximum material removal rate of 44.027 mm3/s with less amplitude of cutting force on the workpiece. The obtained test results show that more optimal surface quality and material removal can be achieved with the optimal set of parameters.

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

Parametric Optimization of EN-31 Steel in Wire Cut Electro Discharge Machining by Taguchi Technique

2020 ◽  
Vol 12 (7) ◽  
pp. 881-887
Author(s):  
Sahil Sharma ◽  
Umesh Kumar Vates ◽  
Amit Bansal
Keyword(s):  
Material Removal Rate ◽  
Automobile Industry ◽  
Material Removal ◽  
Removal Rate ◽  
Dimensional Accuracy ◽  
Work Piece ◽  
Electro Discharge Machining ◽  
En 31 ◽  
The Impact ◽  
Dies And Moulds

Amongst the various methods of machining, Electro Discharge Machining is the convenient alternatives for the industries due to non-contact of work piece and tool. In the study of various EDM processes the main target is to achieve the better finish of surface, high material removal rate and good dimensional accuracy by regulating the different input parameters. There are various applications of EDM such as aerospace parts, medical equipments, dies and moulds, nuclear and automobile industry. In this experimental study, a trial has made to look the impact of input factors like pulse-on, pulse-off, peak current, tension of wire on rate of material removal, gap current and time for machining. Taguchi (L9 OA) and Analysis of Variance technique were used to optimize the outcomes for wire cut EDM of EN-31 tool steel. The outcomes revealed that Ton and Toff are the leading cogent factor for material removal rate and gap current respectively.

scholarly journals Experimental Determination of Cutting Power for Turning and Material Removal Rate for Drilling of AA 6061-T6 Using Vegetable Oils as Cutting Fluid

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Y. M. Shashidhara ◽  
S. R. Jayaram
Keyword(s):  
Vegetable Oils ◽  
Material Removal Rate ◽  
Cutting Forces ◽  
Material Removal ◽  
Removal Rate ◽  
Mineral Oil ◽  
Cutting Fluid ◽  
Cutting Fluids ◽  
Cutting Power ◽  
Thrust Forces

The raw and modified versions of two nonedible vegetable oils, Pongam (Pogammia pinnata) and Jatropha (Jatropha curcas), and a commercially available branded mineral oil are used as straight cutting fluids for turning AA 6061 to assess cutting forces. Minimum quantity lubrication is utilized for the supply of cutting fluids. Cutting and thrust forces are measured. Cutting power is determined for various cutting speeds, depths of cut, and feed rates. Also, drilling is performed on the material to understand the material removal rate (MRR) under these oils. The performances of vegetable oils are compared to mineral oil. A noticeable reduction in cutting forces is observed under the Jatropha family of oils compared to mineral oil. Further, better material removal rate is seen under both the vegetable oils and their versions compared to under petroleum oil for the range of thrust forces.

Analysis of MRR and TWR on OHNS Die Steel with Different Electrodes Using Electrical Discharge Machining

2016 ◽  
Vol 22 ◽  
pp. 112-120 ◽  
Author(s):  
S. Nallusamy
Keyword(s):  
Wear Rate ◽  
Tool Wear ◽  
Material Removal Rate ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Dielectric Fluid ◽  
Work Piece ◽  
Tool Wear Rate

Electrical Discharge Machining is a machining method primarily used for hard metals or those that are impossible to be machined with traditional techniques. The experimental investigation of material removal rate and tool wear rate during machining of oil hardened non-shrinking steel with brass and copper electrodes using EDM machine was carried out in this paper. This investigation presents the analysis and evaluation of heat affected zones and surface finish of the work piece using different tool electrodes and varying the machine parameters. The commercial grade kerosene oil has been used as dielectric fluid. The effect of various important EDM parameters such as discharge current (Ip) 2 to12A, pulse duration (Ton and Toff) and sparking voltage (V) of 80±5% have been used to yield the response in terms of Material Removal Rate (MRR) and Tool Wear Rate (TWR). Further a detailed analysis of the heat affected regions was also been carried out by using scanning electron microscopy.

scholarly journals Multi-Objective Optimization of Aluminium Powder-mixed EDM process using GRA and TOPSIS Technique based on Fuzzy AHP approach

2021 ◽  
Vol 19 (5) ◽  
pp. 437-447
Author(s):  
Fahad Kazi ◽  
C.A Waghmare ◽  
M.S Sohani
Keyword(s):  
Material Removal Rate ◽  
Electric Discharge ◽  
Material Removal ◽  
Removal Rate ◽  
Fuzzy Ahp ◽  
Dielectric Fluid ◽  
Work Piece ◽  
Electric Discharge Machining ◽  
Aluminium Powder ◽  
Pulse On Time

Electric discharge machining is an advanced machining technique. Spark is initiated between the tool and work piece interface which has a gap between them. Low material removal rate as well as low surface finish is a major concern of this process. Therefore, Powder mixed electric discharge machining is developed. In PMEDM process, powders like silicon, aluminium, chromium, manganese, etc. are circulated along with dielectric fluid in a particular proportion. In this present study, aluminium powder is mixed in the dielectric fluid. The responses such as material removal rate, tool wear rate and surface roughness are measured by considering current, pulse on time and aluminium powder concentration as process parameters. Response surface methodology along with Fuzzy AHP TOPSIS and Grey relational analysis are used for optimization.

scholarly journals Theoretical and Experimental Research on a Novel Method of Cluster Magnetorheological Finishing Based on Array Circular Holes Polishing Disk

2021 ◽  
Author(s):  
Bin Luo ◽  
Qiusheng Yan ◽  
Jingfu Chai ◽  
Wenqing Song ◽  
Jisheng Pan
Keyword(s):  
Material Removal Rate ◽  
Shear Force ◽  
Material Removal ◽  
High Performance ◽  
Removal Rate ◽  
Solid Particles ◽  
Force Model ◽  
Magnetorheological Finishing ◽  
Circular Holes ◽  
Novel Method

Abstract with the high performance of microelectronic and optoelectronic devices, the new generation of optoelectronic wafers is developing in the direction of large size and ultra-thinning, which requires ultra-smooth surfaces with sub-nanometer surface roughness. It puts forward new requirements and challenges for the efficient and ultra-smooth planarization processing of optoelectronic wafers. This paper proposes a novel method of cluster magnetorheological finishing based on array circular holes polishing disk, which can effectively improve the polishing shear force and polishing efficiency. The appropriate polishing shear force and material removal rate are the keys to achieve low roughness and low damage processing of optoelectronic wafers. Therefore, the shear force model of solid particles in magnetorheological finishing fluid is established based on the tribological principle. The material removal rate model is established by combining the polishing shear force model with the velocity model. The correctness of the above model is verified by the rotary dynamometer and repeated single-factor experiments. The errors between theoretical and experimental values of polishing shear force and material removal rate are 8.8% and 10.8%, respectively. The new magnetorheological finishing method can realize the efficient and ultra-smooth planarization of optoelectronic wafers. The established model can theoretically guide the optimization of the surface structure and polishing process of polishing disks.

Model-Based Control of Three Degrees of Freedom Robotic Bulldozing

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Scott G. Olsen ◽  
Gary M. Bone
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Removal Rate ◽  
Optimal Controller ◽  
Control Laws ◽  
Rule Based ◽  
Three Degrees Of Freedom

This brief paper investigates the control of a robotic bulldozing operation. Optimal blade position control laws were designed based on a hybrid dynamic model to maximize the predicted material removal rate of the bulldozing process. Experiments were conducted with a scaled-down robotic bulldozing system. The control laws were implemented with various tuning values. As a comparison, a rule-based blade control algorithm was also designed and implemented. The experimental results with the best optimal controller demonstrated a 33% increase in the average material removal rate compared to the rule-based controller.

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