Modulation-Assisted Machining: A New Paradigm in Material Removal Processes

2011 ◽  
Vol 223 ◽  
pp. 514-522 ◽  
Author(s):  
James B. Mann ◽  
Yang Guo ◽  
Christopher Saldana ◽  
Ho Yeung ◽  
W. Dale Compton ◽  
...  
Keyword(s):  
Tool Wear ◽  
Chip Formation ◽  
Material Removal ◽  
Surface Texturing ◽  
Low Frequency ◽  
Contact Condition ◽  
New Paradigm ◽  
Machining Performance ◽  
Removal Processes ◽  
Conventional Machining

Modulation Assisted Machining (MAM), based on controlled superimposition of low-frequency modulation to conventional machining, effects discrete chip formation and disrupts the severe contact condition at the tool-chip interface. The underlying theory of discrete chip formation and its implications are briefly described and illustrated. Benefits such as improved chip management and lubrication, reduction of tool wear, enhanced material removal, particulate manufacturing and surface texturing are highlighted using case studies. MAM represents a new paradigm for machining in that it deliberately employs ‘good vibrations’ to enhance machining performance and capability.

Incipient Plastic Strain Fields in Material Removal Processes

2014 ◽  
Author(s):  
F. Du ◽  
C. Moreno ◽  
Z. Wang ◽  
C. Saldana
Keyword(s):  
Flow Field ◽  
Chip Formation ◽  
Material Removal ◽  
Transient Flow ◽  
Surface Texturing ◽  
Shear Plane ◽  
Image Correlation ◽  
Removal Processes ◽  
Mechanical Surface

Knowledge of the plasticity associated with the incipient stage of chip formation is important for understanding the flow field underlying transient material removal processes. The transition from an incipient state of strain to steady-state was investigated in chip formation of copper. Characterization of the flow field was made by image correlation, hardness mapping and microstructure measurement. A framework for describing the incipient straining length in chip formation as a function of process parameters was established and explained by effects of the deformation on shear plane morphology. The present results are potentially useful for enabling better informed design of processing configurations wherein transient flow fields contribute significantly to the overall deformation process, such as in grain refinement methods for bulk materials and micro-mechanical surface texturing methods based on machining.

Experimental Investigations into Traveling Wire Electrochemical Spark Machining (TW-ECSM) of Composites

1991 ◽  
Vol 113 (1) ◽  
pp. 75-84 ◽  
Author(s):  
V. K. Jain ◽  
P. Sreenivasa Rao ◽  
S. K. Choudhary ◽  
K. P. Rajurkar
Keyword(s):  
Tool Wear ◽  
Material Removal ◽  
Removal Rate ◽  
Physical Contact ◽  
Experimental Investigations ◽  
Laser Beam Machining ◽  
Industrial Manufacture ◽  
Main Emphasis ◽  
Conventional Machining ◽  
Traveling Wire

Fiber reinforced composites, though relatively new, have already become important engineering materials. So far the main emphasis of research has been on the development of materials, but nowadays more attention is being paid to the industrial manufacture of products made of composites. Conventional machining methods and some unconventional machining methods like laser beam machining (LBM) and water jet machining (WJM) cannot be effectively applied for machining of composites due to the resulting problems of air borne dust, tool wear, and thermal damage. Recently electrochemical spark machining (ECSM) has been applied for the cutting and drilling of holes in composites. The success achieved in the application of ECSM for cutting of composites has stimulated interest in exploring the prospects of use of traveling wire electrochemical spark machining (TW-ECSM) process for cutting of composites. An apparatus for TW-ECSM is designed and fabricated in the laboratory. The results about the feasibility of the process and its performance during machining of composites are presented in this paper. Experiments are carried out on glass-epoxy and kevlar-epoxy composites, using sodium hydroxide (NaOH) as electrolyte. The wire and the workpiece were kept in physical contact with each other by the use of a gravity feed mechanism. The effects of voltage and concentration of the electrolyte on material removal rate, average diametral overcut, tool wear rate, and wire erosion ratio are reported. The theoretical analysis of the mechanism of the process identifies the thermo-mechanical phenomena as the main source of material removal in ECSM.

On the improvement of process performance of hard turning using vibration-assisted machining

2021 ◽  
pp. 251659842110080
Author(s):  
Pranesh Dutta ◽  
Gaurav Bartarya
Keyword(s):  
Tool Wear ◽  
Residual Stresses ◽  
Cutting Forces ◽  
Hard Turning ◽  
Fe Model ◽  
Process Performance ◽  
Machining Performance ◽  
Cutting Velocity ◽  
Low Amplitude ◽  
Conventional Machining

In hard turning, the cutting forces are large, which leads to tool wear and tensile nature of residual stresses. Vibration-assisted machining (VAM), where the tool is provided with a low amplitude vibration at significantly high frequency, might improve the process performance of hard turning in terms of cutting forces, residual stress, etc., as VAM helps in reduction of cutting forces and tool wear significantly. To improve the machining operation, a comparative study of VAM with conventional machining is undertaken to study and improve the hard turning performance. A two-dimensional (2D) finite element (FE) model is developed to understand the effect of process parameters better and to study the effect on machining performance by applying one-dimensional ultrasonic vibration to the tool. The model developed is validated with results from a previous work for continuous hard turning conditions. The effect of vibrations induced in cutting velocity direction is studied on the cutting forces and residual stresses induced on the machined workpiece. The ratio of cutting velocity to critical vibrating velocity is an important process parameter that affects the average cutting forces during hard turning using VAM. The nature of cutting force and temperature for a complete cycle of vibration is also studied. The simulation results establish that hard turning using VAM yields lower average cutting forces and more compressive residual stresses in comparison to conventional hard turning.

scholarly journals Surface and Subsurface Quality of Titanium Grade 23 Machined by Electro Discharge Machining

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 164
Author(s):  
Panagiotis Karmiris-Obratański ◽  
Emmanouil L. Papazoglou ◽  
Beata Leszczyńska-Madej ◽  
Krzysztof Zagórski ◽  
Angelos P. Markopoulos
Keyword(s):  
Tool Wear ◽  
Material Removal Rate ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
White Layer ◽  
Tool Material ◽  
Machining Process ◽  
Machining Performance ◽  
Pulse On Time

Electrical Discharge Machining (EDM) is a non-traditional cutting technology that is extensively utilized in contemporary industry, particularly for machining difficult-to-cut materials. EDM may be used to create complicated forms and geometries with great dimensional precision. Titanium alloys are widely used in high-end applications owing to their unique intrinsic characteristics. Nonetheless, they have low machinability. The current paper includes an experimental examination of EDM’s Ti-6Al-4V ELI (Extra Low Interstitials through controlled interstitial element levels) process utilizing a graphite electrode. The pulse-on current (IP) and pulse-on time (Ton) were used as control parameters, and machining performance was measured in terms of Material Removal Rate (MRR), Tool Material Removal Rate (TMRR), and Tool Wear Ratio (TWR). The Surface Roughness (SR) was estimated based on the mean roughness (SRa) and maximum peak to valley height (SRz), while, the EDMed surfaces were also examined using optical and SEM microscopy and cross-sections to determine the Average White Layer Thickness (AWLT). Finally, for the indices above, Analysis of Variance (ANOVA) was conducted, whilst semi-empirical correlations for the MRR and TMRR were given using the Response Surface Method (RSM). The results show that the pulse-on time is the most significant parameter of the machining process that may increase the MRR up to 354%. Pulse-on current and pulse-on time are shown to have an impact on the surface integrity of the finished product. Furthermore, statistics, SEM, and EDX images on material removal efficiency and tool wear rate are offered to support the core causes of surface and sub-surface damage. The average microhardness of the White Layer (WL) is 1786 HV.

Analysis of Performance Characteristics by Firefly Algorithm-Based Electro Discharge Machining of SS 316

2021 ◽  
pp. 45-54
Author(s):  
Premangshu Mukhopadhyay
Keyword(s):  
Magnetic Field ◽  
Tool Wear ◽  
Firefly Algorithm ◽  
Tool Material ◽  
Machining Process ◽  
Machining Performance ◽  
Machining Processes ◽  
Electro Discharge Machining ◽  
Conventional Machining ◽  
Edm Process

The process of combining two or more non-conventional machining processes to obtain the required machining performance is known as hybridisation. Hybrid electro discharge machining came into the picture of macro machining due to the requirement of more rapid machining process with improved efficiency of non-conventional machining process. The technique of vibration assisted EDM process did not prove to be successful due to some disadvantages like increase in tool wear for low melting and comparatively softer tool material. Therefore, a need for more advanced hybridised process has been realized to improve the overall machining efficiency specially circularity and radial overcut. A permanent magnetic field force assisted EDM process was carried out on SS 316 plate with tungsten carbide tool of 5 mm diameter. MRR, TWR, and diametral overcut have been optimized by firefly algorithm technique which showed satisfactory results. It has been found that tool wear and diametral overcut has been found to be reduced with magnetic field-assisted EDM than conventional EDM processes.

Mechanics of Modulation Assisted Machining

2013 ◽  
Author(s):  
Ho Yeung ◽  
Yang Guo ◽  
Narayan K. Sundaram ◽  
James B. Mann ◽  
W. Dale Compton ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Specific Energy ◽  
Frequency Modulation ◽  
Chip Formation ◽  
Low Frequency ◽  
Contact Condition ◽  
Force Measurements

The controlled application of low-frequency modulation to machining — Modulation Assisted Machining (MAM) — effects discrete chip formation and disrupts the severe contact condition at the tool-chip interface. The role of modulation in reducing the specific energy of machining with ductile alloys is demonstrated using direct force measurements. The observed changes in energy dissipation are analyzed and explained, based on the mechanics of chip formation.

An Improvised Method of Machinability Evaluation with Predictive Temperature Model for Inconel 625: A Holistic Machinist’s Perspective

2021 ◽  
Vol 18 (2) ◽  
Author(s):  
P. Singh ◽  
C. Padhy
Keyword(s):  
Tool Wear ◽  
High Heat ◽  
Cutting Fluid ◽  
Inconel 625 ◽  
Surface Finishing ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Temperature Model ◽  
Machining Performance ◽  
Conventional Machining

Machinability of any material is defined as how easily it can be machined (cut) and the factors that govern this machinability comprise machining temperature, tool wear, surface roughness, and the shape of the chip. To enhance the machinability of materials, the improvement of these governing factors is a must. In this regards machinability of Nickel alloys is of great concern as they are associated with problems of high heat generation causing tool wear and poor surface finishing, which adds to the product cost. Therefore, this research aims to improve the machinability of Inconel 625 with the use of MQL assisted with h-BN nano cutting fluid. A comparative study of machining performance of h-BN NMQL with dry and MQL conventional conditions is performed. The outcomes of this study establish the superiority of h-BN over dry machining and MQL conventional machining on various machining parameters by reducing both machining temperature and tool wear. The experimental results revealed that the machining with nano h-BN MQL technique reduces the machining tool tip temperature by 25% and 12%, along with the reduction in tool wear by 67% and 47% in comparison with dry and MQL machining. Additionally, this paper also proposes a numerical model for predicting machining tool temperature using machining parameters (speed, feed and depth of cut) during turning of Inconel 625 under nano h-BN MQL technique.

A Comparative Study of Energy and Material Flow in Modulation-Assisted Machining and Conventional Machining

2014 ◽  
Author(s):  
Ho Yeung ◽  
Yang Guo ◽  
James B. Mann ◽  
W. Dale Compton ◽  
Srinivasan Chandrasekar
Keyword(s):  
Chip Formation ◽  
Material Flow ◽  
High Speed ◽  
Unique Feature ◽  
Low Frequency ◽  
Ductile Metals ◽  
Simultaneous Measurements ◽  
Formation Zone ◽  
Conventional Machining

A study has been made of deformation, forces and energy in modulation-assisted machining (MAM), wherein chip formation occurs in the presence of a controlled, low-frequency modulation superimposed on to the machining. A unique feature of the study is the use of high speed in situ imaging and image analysis to map material flow in the chip formation zone at high resolution; and simultaneous measurements of tool motions and forces, such that the instantaneous forces can be overlaid onto the chip formation process. The measurements show that the observed significant reductions in specific energy in MAM relative to conventional machining, when cutting ductile metals such as copper and Al 6061T6, are a consequence of chip formation with reduced strain levels in MAM. Additional insights into the chip formation are obtained by examining the effects of a chip aspect ratio parameter.

Effect of SiC-Cu Electrode on Material Removal Rate, Tool Wear and Surface Roughness in EDM Process

2020 ◽  
Vol 38 (9A) ◽  
pp. 1406-1413
Author(s):  
Yousif Q. Laibia ◽  
Saad K. Shather
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Material Removal Rate ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
304 Stainless Steel ◽  
Tool Electrode ◽  
Pulse Time ◽  
Edm Process

Electrical discharge machining (EDM) is one of the most common non-traditional processes for the manufacture of high precision parts and complex shapes. The EDM process depends on the heat energy between the work material and the tool electrode. This study focused on the material removal rate (MRR), the surface roughness, and tool wear in a 304 stainless steel EDM. The composite electrode consisted of copper (Cu) and silicon carbide (SiC). The current effects imposed on the working material, as well as the pulses that change over time during the experiment. When the current used is (8, 5, 3, 2, 1.5) A, the pulse time used is (12, 25) μs and the size of the space used is (1) mm. Optimum surface roughness under a current of 1.5 A and the pulse time of 25 μs with a maximum MRR of 8 A and the pulse duration of 25 μs.

Optimization of Cutting Parameters in Milling Process Using Genetic Algorithm and ANOVA (March 2020)

2020 ◽  
Vol 38 (10A) ◽  
pp. 1489-1503
Author(s):  
Marwa Q. Ibraheem
Keyword(s):  
Genetic Algorithm ◽  
Tool Wear ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Optimal Value ◽  
Optimization Of Cutting Parameters

In this present work use a genetic algorithm for the selection of cutting conditions in milling operation such as cutting speed, feed and depth of cut to investigate the optimal value and the effects of it on the material removal rate and tool wear. The material selected for this work was Ti-6Al-4V Alloy using H13A carbide as a cutting tool. Two objective functions have been adopted gives minimum tool wear and maximum material removal rate that is simultaneously optimized. Finally, it does conclude from the results that the optimal value of cutting speed is (1992.601m/min), depth of cut is (1.55mm) and feed is (148.203mm/rev) for the present work.

Sign in / Sign up

Export Citation Format

Share Document