Analytical Modelling of Friction Along Tool Chip Interface for Inconel 718

2017 ◽  
Author(s):  
Abhishek Kumar ◽  
Basil Kuriachen ◽  
Surender Ontela
Keyword(s):  
Shear Zone ◽  
Analytical Model ◽  
Coefficient Of Friction ◽  
Inconel 718 ◽  
Weight Ratio ◽  
Constant Thickness ◽  
Depth Of Cut ◽  
Shear Stresses ◽  
Apparent Coefficient Of Friction ◽  
Secondary Shear Zone

Inconel 718 is gaining its importance in the aerospace and power plant industries because of its high strength to weight ratio. The lack of understanding of the tool chip interface for Inconel 718 restricts the prediction of the apparent coefficient of friction and thus the cutting forces, thereby the machining efficiency. In the present study an analytical model has been developed accounting the actual variation of stresses over the rake face. The model focuses on the variation of shear stresses in the sticking region and has been considered to be increasing exponentially with distance from tool tip. The primary shear zone is assumed to be a thin layer with constant thickness and has been modelled using Johnson Cook material model. The shear stresses at the entry and exit of the primary shear zone has been calculated using iterative techniques proposed in the literature. The secondary shear zone has been analyzed dividing the contact length into two distinct regions and each region has been dealt separately. The ratio of real area of contact to the apparent area of contact has been given consideration and dealt with at macroscopic level. Experimental values have been extracted from previous studies on Inconel 718. The predictions of the analytical model was found to be in good agreement with experimental results. The experimental apparent coefficient of friction was obtained as 0.5119 against 0.4733 from the developed model at a velocity of 70 mm/min, depth of cut of 1mm, nose radius of 0.8mm and with negative rake angle (−6°) with CNMG0812 tool. The predicted and the experimental friction coefficient showed a variation of 7.07% – 10% and thus can serve as reliable model for Inconel 718.

Parameter Optimization of Ball End Milling Process on Inconel 718 Using RSM and TLBO Algorithm

2015 ◽  
Vol 15 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Nandkumar N. Bhopale ◽  
Nilesh Nikam ◽  
Raju S. Pawade
Keyword(s):  
Surface Roughness ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Surface Integrity ◽  
Inconel 718 ◽  
Tool Path ◽  
End Milling ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Ball End Milling

AbstractThis paper presents the application of Response Surface Methodology (RSM) coupled with Teaching Learning Based Optimization Technique (TLBO) for optimizing surface integrity of thin cantilever type Inconel 718 workpiece in ball end milling. The machining and tool related parameters like spindle speed, milling feed, axial depth of cut and tool path orientation are optimized with considerations of multiple response like deflection, surface roughness, and micro hardness of plate. Mathematical relationship between process parameters and deflection, surface roughness and microhardness are found out by using response surface methodology. It is observed that after optimizing the process that at the spindle speed of 2,000 rpm, feed 0.05 mm/tooth/rev, plate thickness of 5.5 mm and 15° workpiece inclination with horizontal tool path gives favorable surface integrity.

scholarly journals Cutting Force Prediction Models by FEA and RSM When Machining X56 Steel with Single Diamond Grit

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 326
Author(s):  
Lan Zhang ◽  
Xianbin Sha ◽  
Ming Liu ◽  
Liquan Wang ◽  
Yongyin Pang
Keyword(s):  
Cutting Force ◽  
Coefficient Of Friction ◽  
High Speed ◽  
Prediction Models ◽  
Pipeline Steel ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Cutting Force Prediction ◽  
Force Prediction ◽  
Diamond Wire Saw

In the field of underwater emergency maintenance, submarine pipeline cutting is generally performed by a diamond wire saw. The process, in essence, involves diamond grits distributed on the surface of the beads cutting X56 pipeline steel bit by bit at high speed. To find the effect of the different parameters (cutting speed, coefficient of friction and depth of cut) on cutting force, the finite element (FEA) method and response surface method (RSM) were adopted to obtain cutting force prediction models. The former was based on 64 simulations; the latter was designed according to DoE (Design of Experiments). Confirmation experiments were executed to validate the regression models. The results indicate that most of the prediction errors were within 10%, which were acceptable in engineering. Based on variance analyses of the RSM models, it could be concluded that the depth of the cut played the most important role in determining the cutting force and coefficient the of friction was less influential. Despite making little direct contribution to the cutting force, the cutting speed is not supposed to be high for reducing the coefficient of friction. The cutting force models are instructive in manufacturing the diamond beads by determining the protrusion height of the diamond grits and the future planning of the cutting parameters.

Micro Textured Cutting Inserts with Solid Lubrication as Alternative Coolant to Mineral Oil-Based Cutting Fluid in Turning Operation

2021 ◽  
Vol 13 (4) ◽  
Author(s):  
C. Divya ◽  
L. Suvarna Raju ◽  
B. Singaravel
Keyword(s):  
Process Parameters ◽  
Orthogonal Array ◽  
Inconel 718 ◽  
Cutting Speed ◽  
Solid Lubricants ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Turning Process ◽  
Optimization Of Process Parameters ◽  
Cutting Inserts

Turning process is a primary process in engineering industries and optimization of process parameters enhance the machining performance. Inconel 718 is a nickel-based superalloy, widely found applications in the manufacturing of blades, sheets and discs in aircraft engines and rocket engines. It provides toughness at low temperature, with stand high mechanical stresses at elevated temperature and creep resistance. In this work, turning process is carried out on Inconel 718 with micro whole textured cutting inserts filled with solid lubricants. Three different solid lubricants are used namely molybdenum-di-sulfide (MoS2), tungsten-di-sulfide (WS2) and calcium-di-fluoride (CaF2). Experiments are performed as per L9 orthogonal array. Statistical approaches such as orthogonal array, Signal-to-Noise (S/N) ratio and Analysis of Variance (ANOVA) are used to find the importance and effects of machining parameters. In this study, input parameters included are feed, cutting speed and depth of cut and output parameter includes surface roughness. Optimization of process parameters is carried out and the significance is estimated. The result suggested that WS2 followed by MoS2 and CaF2 given good surface finish value. Also, solid lubricant in machining enhances the sustainability in manufacturing.

scholarly journals Insights into Machining of a β Titanium Biomedical Alloy from Chip Microstructures

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 710 ◽  
Author(s):  
Damon Kent ◽  
Rizwan Rahman Rashid ◽  
Michael Bermingham ◽  
Hooyar Attar ◽  
Shoujin Sun ◽  
...  
Keyword(s):  
Shear Band ◽  
Shear Zone ◽  
Biomechanical Properties ◽  
Temperature Fields ◽  
Large Strains ◽  
Shear Direction ◽  
Grain Sizes ◽  
Β Phase ◽  
Secondary Shear Zone ◽  
Cutting Speeds

New metastable β titanium alloys are receiving increasing attention due to their excellent biomechanical properties and machinability is critical to their uptake. In this study, machining chip microstructure has been investigated to gain an understanding of strain and temperature fields during cutting. For higher cutting speeds, ≥60 m/min, the chips have segmented morphologies characterised by a serrated appearance. High levels of strain in the primary shear zone promote formation of expanded shear band regions between segments which exhibit intensive refinement of the β phase down to grain sizes below 100 nm. The presence of both α and β phases across the expanded shear band suggests that temperatures during cutting are in the range of 400–600 °C. For the secondary shear zone, very large strains at the cutting interface result in heavily refined and approximately equiaxed nanocrystalline β grains with sizes around 20–50 nm, while further from the interface the β grains become highly elongated in the shear direction. An absence of the α phase in the region immediately adjacent to the cutting interface indicates recrystallization during cutting and temperatures in excess of the 720 °C β transus temperature.

Improvement of Surface Roughness in End Milling of Ti6Al4V by Coupling RSM with Genetic Algorithm

2011 ◽  
Vol 264-265 ◽  
pp. 1154-1159
Author(s):  
Anayet Ullah Patwari ◽  
A.K.M. Nurul Amin ◽  
S. Alam
Keyword(s):  
Genetic Algorithm ◽  
Surface Roughness ◽  
Titanium Alloys ◽  
End Milling ◽  
Fitness Function ◽  
Cutting Speed ◽  
Weight Ratio ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Resistance Surface

Titanium alloys are being widely used in the aerospace, biomedical and automotive industries because of their good strength-to-weight ratio and superior corrosion resistance. Surface roughness is one of the most important requirements in machining of Titanium alloys. This paper describes mathematically the effect of cutting parameters on Surface roughness in end milling of Ti6Al4V. The mathematical model for the surface roughness has been developed in terms of cutting speed, feed rate, and axial depth of cut using design of experiments and the response surface methodology (RSM). Central composite design was employed in developing the surface roughness models in relation to primary cutting parameters. The experimental results indicate that the proposed mathematical models suggested could adequately describe the performance indicators within the limits of the factors that are being investigated. The developed RSM is coupled as a fitness function with genetic algorithm to predict the optimum cutting conditions leading to the least surface roughness value. MATLAB 7.0 toolbox for GA is used to develop GA program. The predicted results are in good agreement with the experimental one and hence the model can be efficiently used to achieve the minimum surface roughness value.

scholarly journals Milling Inconel 718 Workpiece With Cryogenically Treated And Untreated Cutting Tools

2021 ◽  
Author(s):  
Hüseyin Gürbüz ◽  
Şehmus Baday
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Abrasive Wear ◽  
Inconel 718 ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Cutting Tool Wear ◽  
Feed Force

Abstract Although Inconel 718 is an important material for modern aircraft and aerospace, it is a kind material, which is known to have low machinability. Especially, while these types of materials are machined, high cutting temperatures, BUE on cutting tool, high cutting forces and work hardening occur. Therefore, in recent years, instead of producing new cutting tools that can withstand these difficult conditions, cryogenic process, which is a heat treatment method to increase the wear resistance and hardness of the cutting tool, has been applied. In this experimental study, feed force, surface roughness, vibration, cutting tool wear, hardness and abrasive wear values that occurred as a result of milling of Inconel 718 material by means of cryogenically treated and untreated cutting tools were investigated. Three different cutting speeds (35-45-55 m/min) and three different feed rates (0.02-0.03-0.04 mm/tooth) at constant depth of cut (0.2 mm) were used as cutting parameters in the experiments. As a result of the experiments, lower feed forces, surface roughness, vibration and cutting tool wear were obtained with cryogenically treated cutting tools. As the feed rate and cutting speed were increased, it was seen that surface roughness, vibration and feed force values increased. At the end of the experiments, it was established that there was a significant relation between vibration and surface roughness. However, there appeared an inverse proportion between abrasive wear and hardness values. While BUE did not occur during cryogenically treated cutting tools, it was observed that BUE occurred in cutting tools which were not cryogenically treated.

The Effect of Material Flow Stress on Analytical Simulation of Machining

2010 ◽  
Vol 29-32 ◽  
pp. 1809-1814
Author(s):  
Bing Lin Li ◽  
Ling Ling ◽  
Yu Jin Hu ◽  
Xue Lin Wang
Keyword(s):  
Flow Stress ◽  
Shear Zone ◽  
Analytical Model ◽  
Material Flow ◽  
Model Simulation ◽  
Orthogonal Cutting ◽  
Shear Plane ◽  
Thermomechanical Model ◽  
Workpiece Material ◽  
Flow Stress Data

The flow stress data of the workpiece are extremely crucial for the cutting simulation. The study shows how the input data affect the analytical predictions of cutting force and temperature. The Johnson-Cook material model is used to represent workpiece flow stress in the primary shear zone. A thermomechanical model of orthogonal cutting is proposed based on the main shear plane divides the primary shear zone into two unequal parts. Five different sets of workpiece material flow stress data used in the Johnson-Cook’s constitutive equation are chosen and make the sensitivity analysis for analytical model. Simulation results were compared to orthogonal cutting test data from the available literature, and find the effects of flow stress on analytical model was different from that for finite element model.

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