scholarly journals Thermal Modeling of Tool Temperature Distribution during High Pressure Coolant Assisted Turning of Inconel 718

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 408 ◽  
Author(s):  
Doriana D'Addona ◽  
Sunil Raykar
Keyword(s):  
High Pressure ◽  
Temperature Distribution ◽  
Inconel 718 ◽  
Tool Temperature ◽  
Machining Processes ◽  
Nickel Chromium ◽  
Work Material ◽  
Cutting Zone ◽  
Overall Performance ◽  
High Pressure Coolant

This paper presents a finite-element modeling (FEM) of tool temperature distribution during high pressure coolant assisted turning of Inconel 718, which belongs to the heat resistance superalloys of the Nickel-Chromium family. Machining trials were conducted under four machining conditions: dry, conventional wet machining, high pressure coolant at 50 bar, and high pressure coolant at 80 bar. Temperature during machining plays a very important role in the overall performance of machining processes. Since in the current investigation a high pressure coolant jet was supplied in the cutting zone between tool and work material, it was a very difficult task to measure the tool temperature correctly. Thus, FEM was used as a modeling tool to predict tool temperature. The results of the modeling showed that the temperature was considerably influenced by coolant pressure: the high pressure jet was able to penetrate into the interface between tool and work material, thus providing both an efficient cooling and effective lubricating action.

Evaluating the use of high-pressure coolant in turning process of Inconel 625 nickel-based alloy

2016 ◽  
Vol 232 (7) ◽  
pp. 1182-1192 ◽  
Author(s):  
Aristides Magri ◽  
Anselmo Eduardo Diniz ◽  
Daniel Iwao Suyama
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Tool Life ◽  
Weight Ratio ◽  
Inconel 625 ◽  
Mechanical Resistance ◽  
Machining Processes ◽  
Nickel Based Alloy ◽  
Increase Tool Life ◽  
High Pressure Coolant

The automotive, aerospace and energy industries have lately increased their search for materials which must have high mechanical resistance/weight ratio and capability to maintain the mechanical properties in high temperatures and at corrosive environments in order to produce critical parts of their equipment. The nickel-based alloys are one type of materials which have been a good answer for this search. On the other hand, the very good mechanical properties of these alloys make their manufacturing very difficult, especially when machining processes are used. Among other problems in the machining of these alloys, due to the high mechanical resistance in high temperature, tool lives used to be much shorter than when steel alloys are machined, forcing cutting speeds to be much lower and, consequently, to have less productive processes. The main goal of this work was to test an alternative to increase tool life in the turning of Inconel 625 nickel-based alloy by the use of high-pressure coolant. This system was tested using different directions of the fluid flow (toward the rake face, toward the flank face and directing the fluid simultaneously toward these two tool faces) compared to the conventional way of applying fluid. The results show that the use of high-pressure coolant harms the notch wear development and, consequently, increases tool life with simultaneous improvement of workpiece surface roughness in some cases. However, the application of high-pressure coolant over both flank and rake faces at the same time did not provide any improvement.

scholarly journals Media-assisted machining processes

Mechanik ◽  
2018 ◽  
Vol 91 (12) ◽  
pp. 1050-1056
Author(s):  
Wit Grzesik
Keyword(s):  
High Pressure ◽  
Material Removal ◽  
Tribological Behavior ◽  
Removal Rate ◽  
Subsurface Layer ◽  
Optimization Procedure ◽  
Special Group ◽  
Machining Processes ◽  
Gaseous Media ◽  
Cutting Zone

A special group of hybrid assisted processes termed media-assisted processes which various liquid and gaseous media supplied to the cutting zone is highlighted. Special attention is paid on such cooling techniques as high-pressure machining (HPC), high-pressure jet assisted machining (HPJAM), minimum quantity cooling/lubrication (MQC/MQL) and a group of cryogenically cooled machining including such cryogenic media as CO2 snow and liquid nitrogen (LN2). Some important effects resulting from the various cooling strategies are outlined and compared. In particular, quantitative effects concerning chip breaking, thermal and tribological behavior of the cutting process as well as burr reduction, surface quality and subsurface layer are presented. The optimization procedure concerning both energy consumption and machining costs in terms of material removal rate (MRR) is presented.

scholarly journals Stability Analysis of Radial Turning Process for Superalloys

2017 ◽  
Vol 25 (3) ◽  
pp. 158-162
Author(s):  
Alberto Jiménez ◽  
Fernando Boto ◽  
Itziar Irigoien ◽  
Basilio Sierra ◽  
Alfredo Suarez
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
High Pressure ◽  
Stability Analysis ◽  
Real Data ◽  
Turning Process ◽  
Machining Processes ◽  
Pca Method ◽  
Automatic Methods ◽  
High Pressure Coolant

Abstract Stability detection in machining processes is an essential component for the design of efficient machining processes. Automatic methods are able to determine when instability is happening and prevent possible machine failures. In this work a variety of methods are proposed for detecting stability anomalies based on the measured forces in the radial turning process of superalloys. Two different methods are proposed to determine instabilities. Each one is tested on real data obtained in the machining of Waspalloy, Haynes 282 and Inconel 718. Experimental data, in both Conventional and High Pressure Coolant (HPC) environments, are set in four different states depending on materials grain size and Hardness (LGA, LGS, SGA and SGS). Results reveal that PCA method is useful for visualization of the process and detection of anomalies in online processes.

scholarly journals Cutting Zone Temperature Identification During Machining of Nickel Alloy Inconel 718

2017 ◽  
Vol 14 (2) ◽  
pp. 24-29
Author(s):  
Andrej Czán ◽  
Igor Daniš ◽  
Jozef Holubják ◽  
Lucia Zaušková ◽  
Tatiana Czánová ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Inconel 718 ◽  
Cutting Temperature ◽  
Cutting Edge ◽  
Cutting Process ◽  
Maximum Temperature ◽  
Machining Processes ◽  
Machined Surface ◽  
Cutting Zone

Abstract Quality of machined surface is affected by quality of cutting process. There are many parameters, which influence on the quality of the cutting process. The cutting temperature is one of most important parameters that influence the tool life and the quality of machined surfaces. Its identification and determination is key objective in specialized machining processes such as dry machining of hard-to-machine materials. It is well known that maximum temperature is obtained in the tool rake face at the vicinity of the cutting edge. A moderate level of cutting edge temperature and a low thermal shock reduce the tool wear phenomena, and a low temperature gradient in the machined sublayer reduces the risk of high tensile residual stresses. The thermocouple method was used to measure the temperature directly in the cutting zone. An original thermocouple was specially developed for measuring of temperature in the cutting zone, surface and subsurface layers of machined surface. This paper deals with identification of temperature and temperature gradient during dry peripheral milling of Inconel 718. The measurements were used to identification the temperature gradients and to reconstruct the thermal distribution in cutting zone with various cutting conditions.

Hardness-Based Flow Stress for Numerical Simulation of Machining Inconel 718 Alloy

2012 ◽  
Vol 504-506 ◽  
pp. 1287-1292
Author(s):  
Domenico Umbrello ◽  
Serafino Caruso ◽  
Giovanna Rotella
Keyword(s):  
Flow Stress ◽  
Inconel 718 ◽  
Chip Morphology ◽  
Constitutive Law ◽  
Machining Processes ◽  
Inconel 718 Alloy ◽  
Work Material ◽  
Material Hardness ◽  
Wide Range ◽  
Hardness Values

The phenomenological models for material flow stress and fracture, typically used in the Finite Element simulations of Inconel 718 alloy during machining processes, are often deemed to represent only certain metallurgical material states. In contrast, these models are not suitable to describe the constitutive behaviour of the workpiece for different metallurgical states (i.e., annealed, aged, etc.) and, consequently, different hardness values. Since the description of the material behaviour requires correct formulation of the constitutive law, new flow stress models which include also the hardness effect should be developed and, accordingly used, for computer simulation of machining Inconel alloy. This paper describes the development of a hardness-based flow stress and fracture models for machining Inconel 718 alloy, which can be applied for a wide range of work material hardness. These models have been implemented in a non-isothermal viscoplastic numerical model to simulate the influence of work material hardness on the chip formation process. The predicted results are being validated with experimental results available in literature. They are found to satisfactory predict the cutting forces, the temperature, the shear angle and the chip morphology from continuous to segmented chip as the hardness values change.

Increasing Productivity and Process Stability in Turning of Aerospace Materials with High Pressure Lubricoolant Supply

2016 ◽  
Vol 836-837 ◽  
pp. 48-55 ◽  
Author(s):  
Fritz Klocke ◽  
Tolga Cayli ◽  
Dražen Veselovac
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Cutting Parameters ◽  
Experimental Investigations ◽  
Process Stability ◽  
Aerospace Materials ◽  
Tool Temperature ◽  
Temperature Reference ◽  
Cutting Zone ◽  
Cooling And Lubrication

In the field of machining difficult-to-cut materials like titanium or nickel-based alloys, the use of a high-pressure lubricoolant supply may result in a significant increase of productivity and process stability. Due to enhanced cooling and lubrication of the cutting zone and thus reduced thermal tool load, tool wear can be decreased which allows higher applicable cutting speeds. Furthermore, the process stability can be increased as a result of effective chip breaking and chip evacuation. Since energy efficiency is very crucial, pressure and flow rate have to be adjusted carefully and in accordance with the cutting parameters to guarantee best results with less energy. For this purpose, experimental investigations were carried out under variation of the flow rate in order to find the minimum required value for a certain machining task with the overall aim to prevent waste of the media used. To maximize the positive effect of high pressure lubricoolant supply strategy on productivity and process stability, specially designed lubricoolant jet guidance geometry on the rake face was also investigated and compared to conventional turning inserts. To study the effect of high-pressure lubricoolant supply on tool temperature, reference tests also carried out using conventional overflood cooling (CoC). The results suggest that the tool temperature can be significantly decreased compared to CoC by applying the high pressure lubricoolant supply and using specially designed jet guidance geometry in turning the investigated aerospace materials TiAl6V4 and Inconel 718.

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