Investigation of the Impact of Orthogonal Cutting Processes on Nanocrystalline Surface Layer Generation

2013 ◽  
Vol 554-557 ◽  
pp. 2009-2020 ◽  
Author(s):  
Volker Schulze ◽  
Frederik Zanger ◽  
Florian Ambrosy
Keyword(s):  
Grain Size ◽  
Surface Layer ◽  
Cutting Force ◽  
Manufacturing Process ◽  
Orthogonal Cutting ◽  
Work Piece ◽  
Passive Force ◽  
Surface Layers ◽  
Cutting Processes ◽  
The Impact

The present work analyzes the influence of an orthogonal machining process on the generation of nanocrystalline surface layers. Thereby, AISI 4140 is used as work piece material. Metallic parts with a severe nanocrystalline grain refinement in the near-surface area show many beneficial properties. Such surface layers considerably influence the friction and wear characteristics of the work piece in a subsequent usage as design elements working under tribological loads. The focus of this paper is an experimental analysis of a finishing orthogonal cutting operation, carried out with a broaching machine, to generate nanocrystalline surface layers. The influence of process and geometry parameters on the generation of nanocrystalline surfaces is investigated with the aim to massively decrease the grain size in the work piece surface layer. Parameters that are studied and taken into account in the manufacturing process are cutting edge radius rβ, depth of cut h and cutting velocity vc. The cutting edge radius rβ is modified by a drag finishing process. The generation of nanocrystalline surface layers is especially influenced by the design of the uncoated carbide cutting tools. Additionally, cutting force Fc and passive force Fp are determined by a 3-component dynamometer to calculate the relationship between specific cutting force kc and specific passive force kp. The temperature beneath the clearance face is detected by a fiber optic pyrometer. These measurement methods and devices are applied to detect the impact of the most relevant measurement values occurring during machining and causing a drastic reduction of grain size in the surface layer. The evaluation of the manufacturing process is carried out by detailed analyses of the microstructural conditions in the surface layer after processing using a Focused Ion Beam (FIB) system. These material characterizations provide information about the surface engineering concerning the microstructural changes in the surface layer of the work piece due to finishing orthogonal cutting processes.

Molecular Dynamics Study on the Impact of the Cutting Depth to the Titanium Nanometric Cutting

2014 ◽  
Vol 536-537 ◽  
pp. 1431-1434 ◽  
Author(s):  
Ying Zhu ◽  
Yin Cheng Zhang ◽  
Shun He Qi ◽  
Zhi Xiang
Keyword(s):  
Molecular Dynamics ◽  
Potential Energy ◽  
Cutting Force ◽  
Simulation Study ◽  
Cutting Process ◽  
Work Piece ◽  
Cutting Depth ◽  
Nanometric Cutting ◽  
The Impact

Based on the molecular dynamics (MD) theory, in this article, we made a simulation study on titanium nanometric cutting process at different cutting depths, and analyzed the changes of the cutting depth to the effects on the work piece morphology, system potential energy, cutting force and work piece temperature in this titanium nanometric cutting process. The results show that with the increase of the cutting depth, system potential energy, cutting force and work piece temperature will increase correspondingly while the surface quality of machined work piece will decrease.

scholarly journals The cutting behavior of cortical bone in different bone osten cutting angles and depths of cut

2021 ◽  
Author(s):  
Yuanqiang Luo ◽  
Yinghui Ren ◽  
Yang Shu ◽  
Cong Mao ◽  
Zhixiong Zhou ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Cutting Force ◽  
Cortical Bone ◽  
Depth Of Cut ◽  
Cutting Angle ◽  
Small Depth ◽  
Proposed Model ◽  
Cutting Processes ◽  
The Impact ◽  
Cutting Path

Abstract Cortical bones are semi-brittle and anisotropic, this brings the challenge to suppress vibration and avoid undesired fracture in precise cutting processes in surgeries. In this paper, we proposed a novel analytical model to represent cutting processes of cortical bones, and we used to evaluate cutting forces and fracture toughness, and investigate the formations of chips and cracks under varying bone osteon cutting angles and depths. To validate the proposed model, the experiments are conducted on orthogonal cuttings over cortical bones to investigate the impact of bone osteon cutting angle and depth on cutting force, crack initialization and growth, and fracture toughness of cortical bone microstructure. The experimental results highly agreed with the prediction by the proposed model in sense that (1) curly, serrated, grainy and powdery chips were formed when the cutting angle was set as 0°, 60°, 90°, and 120°, respectively. (2) Bone materials were removed dominantly by shearing at a small depth of cut from 10 to 50 µm, and by a mixture of pealing, shearing, and bending at a large depth of cut over 100 µm at different cutting orientations. Moreover, it was found that a cutting path along the direction of crack initialization and propagation benefited to suppress the fluctuation of cutting force thus reduce the vibration. The presented model has theoretical and practical significance in optimizing cutting tools and operational parameters in surgeries.

scholarly journals The kinetic parameters of aerosols formed during combustion of modified wood

2018 ◽  
Vol 251 ◽  
pp. 02023
Author(s):  
Feodor Portnov
Keyword(s):  
Grain Size ◽  
Surface Layer ◽  
Chemical Properties ◽  
Quantitative Composition ◽  
Kinetic Properties ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties ◽  
Modified Wood

The paper studies kinetic properties of aerosols formed in thermal degradation of wood. The impact of modifying agents in wood surface layer on the quantitative composition of smoke aerosol solids was analyzed. For this purpose, grain-size of aerosol solids was analyzed, and the physical and chemical properties of source and modified wood were assessed.

Surface Layers' Real Structure of Metals Exposed to Inhomogeneous Thermal Fields and Plastic Deformation

2010 ◽  
Vol 163 ◽  
pp. 59-63 ◽  
Author(s):  
Zdenek Pala ◽  
N. Ganev ◽  
Jan Drahokoupil ◽  
Alexej Sveshnikov
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Grain Size ◽  
Surface Layer ◽  
Real Structure ◽  
End Mill ◽  
Surface Layers ◽  
Thermal Fields ◽  
Mill Speed

Inhomogeneous thermal fields and plastic deformation are two basic phenomena present during surface creation and substantially determine future real structure of the surface layers. In the following, a closer look will be taken at some aspects connected with real structure of milled and ground steels. Impact of end-mill speed and thickness of removed layer on grain size, macroscopic and microscopic residual stress is discussed. Possibility of prestrained surface layer in ground steel has been examined on a set of five types of steels.

scholarly journals Theory and practice of fatigue strength technological support in machinery

2018 ◽  
Vol 2018 (10) ◽  
pp. 38-42 ◽  
Author(s):  
Анатолий Тотай ◽  
Anatoliy Totay
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Surface Layer ◽  
Fatigue Strength ◽  
Theory And Practice ◽  
Surface Layers ◽  
Technological Support ◽  
Dislocations Density ◽  
Temperature Factors

On a basis of the theory of metal plastic deformation there are determined analytical ties between speed, power and temperature factors of machining with parameters of machinery surface layers defining their resistance to fatigue destructions. The paper reports the technological assurance options for resistance to fatigue by means of the control of such surface layer state parameters of machinery as dislocations density and a grain size of structure material.

Modeling and Experiment of the Cutting Force for Aluminium Alloy Work-Piece

2012 ◽  
Vol 268-270 ◽  
pp. 422-425
Author(s):  
Mu Lan Wang ◽  
Jun Ming Hou ◽  
Bao Sheng Wang ◽  
Wen Zheng Ding
Keyword(s):  
Finite Element ◽  
Aluminium Alloy ◽  
Cutting Force ◽  
Orthogonal Cutting ◽  
Experimental Period ◽  
Production Costs ◽  
Work Piece ◽  
Force Model ◽  
Oblique Cutting ◽  
Cutting Model

The application of Finite Element Method (FEM) in cutting force model for Aluminium alloy work-piece is useful to reduce the production costs and shorten the experimental period. Firstly, the theoretical model of the orthogonal cutting and the oblique cutting are analyzed in this paper. And then, the corresponding finite element models are theoretically constructed. By comparing the results, the following conclusions are drawn: with the increase of the cutting thickness, the cutting force increasing is in an enhancement tendency. The oblique cutting model of overall tool is more conductive to the subsequent runout and the flutter analysis.

scholarly journals Influence of Shot Peening on Abrasion Wear in Real Conditions of Ni-Cu-Ausferritic Ductile Iron

2016 ◽  
Vol 61 (4) ◽  
pp. 1985-1990
Author(s):  
A. N. Wieczorek
Keyword(s):  
Surface Layer ◽  
Abrasive Wear ◽  
Ductile Iron ◽  
Shot Peening ◽  
Residual Austenite ◽  
Wear Properties ◽  
Surface Layers ◽  
Cast Irons ◽  
Dynamic Surface ◽  
The Impact

Abstract The paper presents results of the wear tests of chain wheels made of austempered ductile iron with various content of residual austenite. The aim of this study was to demonstrate the impact of the dynamic surface treatment (shot peening) on wear properties of surface layers of the chain wheels tested that were subjected to the action of quartz abrasive. Apart from determining the value of the abrasive wear, examinations of the magnetic phase content in the microstructure were carried out and plots of hardness of the surface layer as a function of the distance from the surface and microstructure of the materials were prepared. Based on the results, the following was found: an increase in the abrasive wear and a reduction in the hardness of the surface layer of chain wheels subjected to shot peening, as well as reduction of susceptibility to negative action of the shot for cast irons with the structure of upper ausferrite.

An Investigation of Electroplastic Drilling of Mild Steel

2017 ◽  
Author(s):  
Brandt J. Ruszkiewicz ◽  
Farbod Akhavan Niaki ◽  
Laine Mears ◽  
Elizabeth Gendreau
Keyword(s):  
Cutting Force ◽  
Electric Current ◽  
Fuel Economy ◽  
Orthogonal Cutting ◽  
High Strength ◽  
Initial Contact ◽  
Drilling Temperature ◽  
The Cost ◽  
Volume Method ◽  
The Impact

Increasing governmental fuel economy requirements drives automakers to increase the fuel economy of their fleets. One of the methods for improving fuel economy is lightweighting vehicles through the use of materials with high strength to weight ratios. Some of these new metals entering the automotive sector are difficult to machine and cause drastically reduced tool life and increase machining cost. It has been shown that electricity has the ability to reduce cutting force during orthogonal cutting and turning. In this research, a design of experiments study on an electrically assisted drilling operation is conducted to determine the impact and interaction between the following input parameters: applied electric current, feedrate, spindle speed, and number of holes cut. These variables used to determine impact and interaction on the following output variables: flank wear, axial cutting force, and temperature evolution. A 2D finite volume method model is used to predict drilling temperature during the process, and is used to aid in predicting axial force. It is found that electric current can reduce cutting force by 10% for 1008 steel at the cost of increased temperature, however, arcing at initial contact causes increased tool wear at higher current inputs.

Characterization of Cutting Force Induced Surface Shape Variation in Face Milling Using High-Definition Metrology1

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Hai Trong Nguyen ◽  
Hui Wang ◽  
S. Jack Hu
Keyword(s):  
Cutting Force ◽  
Process Monitoring ◽  
Face Milling ◽  
Surface Shape ◽  
Machining Process ◽  
High Definition ◽  
Surface Patterns ◽  
Cutting Processes ◽  
And Control ◽  
The Impact

High-definition metrology (HDM) systems with fine lateral resolution are capable of capturing the surface shape on a machined part that is beyond the capability of measurement systems employed in manufacturing plants today. Such surface shapes can precisely reflect the impact of cutting processes on surface quality. Understanding the cutting processes and the resultant surface shape is vital to high-precision machining process monitoring and control. This paper presents modeling and experiments of a face milling process to extract surface patterns from measured HDM data and correlate these patterns with cutting force variation. A relationship is established between the instantaneous cutting forces and the observed dominant surface patterns along the feed and circumferential directions for face milling. Potential applications of this relationship in process monitoring, diagnosis, and control are also discussed for face milling. Finally a systematic methodology for characterizing cutting force induced surface variations for a generic machining process is presented by integrating cutting force modeling and HDM measurements.

Real-Time Cutting Force Prediction and Cutting Force Coefficient Determination during Machining Processes

2011 ◽  
Vol 223 ◽  
pp. 85-92 ◽  
Author(s):  
Balázs Tukora ◽  
Tibor Szalay
Keyword(s):  
Cutting Force ◽  
Real Time ◽  
Cutting Forces ◽  
End Milling ◽  
Orthogonal Cutting ◽  
Machining Process ◽  
Work Piece ◽  
Processing Unit ◽  
Cutting Force Prediction ◽  
Force Prediction

In this paper a new method for instantaneous cutting force prediction is presented, in case of sculptured surface milling. The method is executed in a highly parallel manner by the general purpose graphics processing unit (GPGPU). As opposed to the accustomed way, the geometric information of the work piece-cutter touching area is gained directly from the multi-dexel representation of the work-piece, which lets us compute the forces in real-time. Furthermore a new procedure is introduced for the determination of the cutting force coefficients on the basis of measured instantaneous or average orthogonal cutting forces. This method can determine the shear and ploughing coefficients even while the cutting geometry is continuously altering, e.g. in the course of multi-axis machining. In this way the cutting forces can be predicted during the machining process without a priori knowledge of the coefficients. The proposed methods are detailed and verified in case of ball-end milling, but the model also enables the applying of general-end cutters.

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