Integration of On-Machine Measurements in the Force Modeling for Machining of Advanced Nickel-Based Superalloys

2012 ◽  
Author(s):  
Andrew Henderson ◽  
Cristina Bunget ◽  
Thomas Kurfess
Keyword(s):  
Cutting Forces ◽  
Gas Turbines ◽  
High Strength ◽  
Extreme Environment ◽  
Subsurface Damage ◽  
Process Models ◽  
Force Model ◽  
Jet Engines ◽  
Part Quality ◽  
Force Modeling

Nickel-based superalloys are specially designed for applications where high strength, creep resistance, and oxidation resistance are critical at high temperatures. Many of their applications are the hot gas sections of turbo-machinery (e.g. jet engines and gas turbines). With greater demands on the performance and efficiency of these types of machines, the firing temperatures are reaching higher levels and nickel-based superalloys are being utilized more because of their excellent mechanical qualities at extreme temperatures. However, the properties that make them attractive for these applications present difficult challenges for the manufacture, particularly machining, of the components that are made from these materials. Considering the extreme environment that these components operate in, part quality, in particular surface quality, is paramount. The damage and stresses introduced to the surfaces of these components during manufacture needs to be well understood and controlled in order to ensure that premature component and machine failures do not occur. With improved process models and on-machine measurement capabilities, the in-process cutting forces and temperatures can be better understood and therefore subsurface damage can be better controlled. Since cutting forces and temperatures are direct contributors to subsurface damage, better control of these aspects would then lead to better control of subsurface damage. This paper discusses the use of on-machine touch probes to measure wear on milling tools and using those measurements to update a mechanistic force model for more accurate prediction of the cutting forces incurred during the milling of nickel-based superalloys.

Analytical cutting force modelling of micro-slot grinding considering tool-workpiece interactions on both primary and secondary tool surfaces

2021 ◽  
pp. 1-43
Author(s):  
Ashwani Pratap ◽  
Karali Patra
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
Orthogonal Cutting ◽  
Surface Interactions ◽  
Surface Interaction ◽  
Edge Density ◽  
Force Model ◽  
Height Distribution ◽  
Force Modeling ◽  
Tool Surface

Abstract This work presents an analytical cutting force modeling for micro-slot grinding. Contribution of the work lies in the consideration of both primary and secondary tool surface interactions with the work surface as compared to the previous works where only primary tool surface interaction was considered during cutting force modeling. Tool secondary surface interaction with workpiece is divided into two parts: cutting/ ploughing by abrasive grits present in exterior margin of the secondary tool surface and sliding/adhesion by abrasive grits in the inner margins of the secondary tool surface. Orthogonal cutting force model and indentation based fracture model is considered for cutting by both the abrasives of primary tool surface and the abrasives of exterior margin on the secondary surface. Asperity level sliding and adhesion model is adopted to solve the interaction between the workpiece and the interior margin abrasives of secondary tool surface. Experimental measurement of polycrystalline diamond tool surface topography is carried out and surface data is processed with image processing tools to determine the tool surface statistics viz., cutting edge density, grit height distribution and abrasive grit geometrical measures. Micro-slot grinding experiments are carried out on BK7 glass at varying feed rate and axial depths of cut to validate the simulated cutting forces. Simulated cutting forces considering both primary and secondary tool surface interactions are found to be much closer to the experimental cutting forces as compared to the simulated cutting forces considering only primary tool surface interaction.

Analysis of Cutting Force in Elastomer End-Milling

2017 ◽  
Vol 11 (6) ◽  
pp. 958-963
Author(s):  
Koji Teramoto ◽  
◽  
Takahiro Kunishima ◽  
Hiroki Matsumoto
Keyword(s):  
Parameter Identification ◽  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Process Models ◽  
Force Model ◽  
Cutting Force Model ◽  
Cutting Force Prediction ◽  
Force Prediction ◽  
The Stability

Elastomer end-milling is attracting attention for its role in the small-lot production of elastomeric parts. In order to apply end-milling to the production of elastomeric parts, it is important that the workpiece be held stably to avoid deformation. To evaluate the stability of workholding, it is necessary to predict cutting forces in elastomer end-milling. Cutting force prediction for metal workpiece end-milling has been investigated for many years, and many process models for end-milling have been proposed. However, the applicability of these models to elastomer end-milling has not been discussed. In this paper, the characteristics of the cutting force in elastomer end-milling are evaluated experimentally. A standard cutting force model and its parameter identification method are introduced. By using this cutting force model, measured cutting forces are compared against the calculated results. The comparison makes it clear that the standard cutting force model for metal end-milling can be applied to down milling for a rough evaluation.

Characterization and Micromilling of Flow Induced Aligned Carbon Nanotube Nanocomposites

2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Mehdi Mahmoodi ◽  
M. G. Mostofa ◽  
Martin Jun ◽  
Simon S. Park
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotube ◽  
Cutting Forces ◽  
End Milling ◽  
Flow Direction ◽  
High Strength ◽  
Force Model ◽  
Micro End Milling ◽  
Different Characteristics ◽  
Milling Forces

Carbon nanotube (CNT) based polymeric composites exhibit high strength and thermal conductivity and can be electrically conductive at a low percolation threshold. CNT nanocomposites with polystyrene (PS) thermoplastic matrix were injection-molded and high shear stress in the flow direction enabled partial alignment of the CNTs. The samples with different CNT concentrations were prepared to study the effect of CNT concentration on the cutting behavior of the samples. Characterizations of CNT polymer composites were studied to relate different characteristics of materials such as thermal conductivity and mechanical properties to micromachining. Micro-end milling was performed to understand the material removal behavior of CNT nanocomposites. It was found that CNT alignment and concentrations influenced the cutting forces. The mechanistic micromilling force model was used to predict the cutting forces. The force model has been verified with the experimental milling forces. The machinability of the CNT nanocomposites was better than that of pure polymer due to the improved thermal conductivity and mechanical characteristics.

Cutting Process Simulation in Micro Dimple Machining

2019 ◽  
Author(s):  
Takashi Matsumura ◽  
Yuji Musha
Keyword(s):  
Cutting Forces ◽  
Rotation Axis ◽  
Flow Direction ◽  
Mechanistic Model ◽  
Cutting Parameters ◽  
Process Models ◽  
Cutting Process ◽  
High Rate ◽  
Force Model ◽  
Micro Dimple

Abstract The paper discusses micro dimple millings with inclined ball end mills. Cutting process models are presented to control the dimple shapes and predict the cutting forces. In micro dimple milling, the cutter rotation axis is inclined to have the non-cutting time, during which the cutting edges don’t remove the material in a rotation of cutter. The end mill is fed at a high rate so that the machining areas removed by the cutting edges are not overlapped each other. The shapes and the alignment of the dimples are simulated for the cutting parameters in the mechanistic model. Then, the cutting forces are predicted for high machining accuracies. The cutting experiments were conducted to verify the micro dimple machining. The dimple shape model is validated in comparison between the simulated and the actual dimple shapes. The cutting forces are simulated to compare the measured ones. The force model works well to predict the cutting forces with the chip flow direction during a rotation of the cutter.

Force Modeling for Generic Profile of Drills

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Kumar Sambhav ◽  
Puneet Tandon ◽  
Sanjay G. Dhande
Keyword(s):  
Cutting Forces ◽  
Arbitrary Point ◽  
Experimental Results ◽  
Tool Geometry ◽  
Force Model ◽  
Force Modeling ◽  
Surface Patches ◽  
Drill Point ◽  
Twist Drills ◽  
Secondary Cutting

The paper presents a methodology to model the cutting forces by twist drills with generic point geometry. A generic definition of point geometry implies that the cutting lips and the relief surfaces can have arbitrary shapes. Such geometry is easily modeled using Non Uniform Rational B-Spline (NURBS) surface patches which give sufficient freedom to the tool designer to alter the tool geometry. The drill point has three cutting zones: primary cutting lips, secondary cutting lips, and the indentation zone at the center of chisel edge. At the indentation zone, the drill extrudes the workpiece, while at the cutting lips, shearing takes place. At primary cutting lip, the cutting is oblique while at secondary cutting lip, it is predominantly orthogonal. Starting from a computer-aided geometric design of a fluted twist drill with arbitrary point profile, the cutting forces have been modeled separately for all the three cutting zones. The mechanistic method has been employed wherever applicable to have a good correlation between the analytical and the experimental results. The force model has been calibrated and validated for conical drills. Then the model has been evaluated for a drill ground with curved relief surfaces. The theoretical and experimental results are found out to be in good conformity.

UNIMAR 250

Alloy Digest ◽  
1974 ◽  
Vol 23 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Gas Turbines ◽  
High Strength ◽  
Heat Treating ◽  
Pressure Vessels ◽  
Notch Toughness ◽  
Jet Engines ◽  
Temperature Performance

Abstract UNIMAR 250 is a maraging alloy steel having high strength, good notch toughness, excellent cryogenic properties and deep hardenability. It is recommended for pressure vessels, solid-fuel rocket cases and pressure bottles, landing-gear components, processing equipment operating in the temperature range of 300 to 600 F, and components for spacecraft, jet engines and gas turbines. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-304. Producer or source: Cyclops Corporation.

Cutting Force Modeling When Milling Nickel-Base Superalloys

2010 ◽  
Author(s):  
Andrew J. Henderson ◽  
Cristina Bunget ◽  
Thomas R. Kurfess
Keyword(s):  
Tool Wear ◽  
Cutting Forces ◽  
Gas Turbines ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Turbine Blades ◽  
Subsurface Damage ◽  
Machining Process ◽  
Nickel Base Superalloys ◽  
Nickel Base

Superalloys are a relatively new class of materials that exhibit high mechanical strength, ductility, creep resistance at high operating temperatures, high fatigue strength, and typically superior resistance to corrosion and oxidation even at elevated temperatures. These properties make superalloys ideal for applications in aircraft, cryogenic tanks, submarines, nuclear reactors, and petrochemical equipment. In the aerospace industry, the most commonly used superalloy is the nickel-base alloy and it accounts for 30–50% of the total material required in the manufacturing of the aircraft engine. It is used for rotating parts of gas turbines such as blades and disks, engine mounts, turbine casings and components for rocket motors and pumps. To make full use of nickel-base superalloys, a machining process must be developed that is capable of controlling and identifying tool wear, and identifying the onset of subsurface damage and controlling its formation during processing. To accomplish this, a model relating process characteristics and cutting parameters need to be developed. Due to high tool wear, the cutting forces increase drastically during machining, thus making impossible to estimate the forces with existing models. This research proposes an update to the specific cutting forces model taking into consideration rapid tool wear. As milling is the most common machining processes used to cut superalloys (e.g., turbine blades), it is specifically targeted by this research. Experiments were conducted under different cutting conditions to observe the cutting characteristics of nickel-base superalloys. Empirical observations were used to formulate updated coefficients. Later this model will be applied for real-time control of the process results, such as geometry, tool wear and subsurface damage, and also for estimation and control of other quantities such as force, deflection, surface quality and energy consumed. This will provide new insights into machining these advanced alloys.

scholarly journals Crack Growth Studies in a Welded Ni-Base Superalloy

2016 ◽  
Vol 258 ◽  
pp. 237-240
Author(s):  
Anand Harihara Subramonia Iyer ◽  
Krystyna Stiller ◽  
Magnus Hörnqvist Colliander
Keyword(s):  
Gas Turbines ◽  
High Strength ◽  
Fatigue Loading ◽  
Main Body ◽  
Alloy 718 ◽  
Jet Engines ◽  
Fine Grained ◽  
Dwell Fatigue ◽  
Corrosion Resistant Alloy

It is well known that the introduction of sustained tensile loads during high-temperature fatigue (dwell-fatigue) significantly increases the crack propagation rates in many superalloys. One such superalloy is the Ni-Fe based Alloy 718, which is a high-strength corrosion resistant alloy used in gas turbines and jet engines. As the problem is typically more pronounced in fine-grained materials, the main body of existing literature is devoted to the characterization of sheets or forgings of Alloy 718. However, as welded components are being used in increasingly demanding applications, there is a need to understand the behavior. The present study is focused on the interaction of the propagating crack with the complex microstructure in Alloy 718 weld metal during cyclic and dwell-fatigue loading at 550 °C and 650 °C.

INCONEL ALLOY X-750

Alloy Digest ◽  
1966 ◽  
Vol 15 (7) ◽  
Keyword(s):  
Gas Turbines ◽  
Rupture Strength ◽  
Low Cost ◽  
High Strength ◽  
Heat Treating ◽  
Chromium Alloy ◽  
Cryogenic Temperatures ◽  
Inconel Alloy ◽  
Nickel Chromium ◽  
Corrosion And Oxidation

Abstract INCONEL alloy X-750 is an age-hardenable, nickel-chromium alloy used for its corrosion and oxidation resistance and high creep rupture strength at temperature up to 1500 F. It also has excellent properties at cryogenic temperatures. It was originally developed for use in gas turbines, but because of its low cost, high strength and weldability it has become the standards choice for a wide variety of applications. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-115. Producer or source: Huntington Alloy Products Division, An INCO Company.

Practical Bypass Mixing Systems for Fan Jet Aero Engines

1966 ◽  
Vol 17 (2) ◽  
pp. 141-160 ◽  
Author(s):  
T. H. Frost
Keyword(s):  
Gas Turbines ◽  
Minimum Weight ◽  
Jet Engines ◽  
Metal Interface ◽  
Combustion Chambers ◽  
Propulsion Systems ◽  
Jet Engine ◽  
Aero Engines ◽  
Corrugated Metal ◽  
Constant Static Pressure

SummaryMixing systems have many applications in gas turbines and aircraft jet propulsion, e.g. mixing zones in combustion chambers, ejectors for jet lift thrust augmentors and supersonic propulsion systems. A further application similar to that of combustion chamber mixing is that of mixing the cold and hot exhausts of a bypass jet engine. These are both characterised by mixing at constant static pressure and approximately constant total pressure as opposed to the more general case of unequal pressures in ejector systems (Fig. 1).The exhaust mixing process as used in Rolls-Royce bypass jet engines, e.g. Spey and Conway, enables the potential of the bypass principle, in terms of minimum weight and fuel consumption, to be exploited by a simple practical device.This is achieved by mixing the two streams in a common duct of fairly short dimensions with a corrugated metal interface on the inlet side. The consideration of these practical systems forms the main topic of this paper.

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