scholarly journals Trochoidal Milling Path with Variable Feed. Application to the Machining of a Ti-6Al-4V Part

Mathematics ◽  
2021 ◽  
Vol 9 (21) ◽  
pp. 2701
Author(s):  
César García-Hernández ◽  
Juan-José Garde-Barace ◽  
Juan-Jesús Valdivia-Sánchez ◽  
Pedro Ubieto-Artur ◽  
José-Antonio Bueno-Pérez ◽  
...  
Keyword(s):  
Nickel Alloys ◽  
Advanced Materials ◽  
Feed Speed ◽  
Trochoidal Milling ◽  
Concave Wall ◽  
High Acceleration ◽  
Milling Tool ◽  
Milling Machines ◽  
Path Geometry ◽  
Experimental Stage

Trochoidal milling is a well-stablished machining strategy which still allows for the introduction of new approaches. This strategy can be applied to any kind of material, although it is usually associated to advanced materials, such as titanium and nickel alloys. This study is based on the adaptation of the feed speed of a milling tool with Ti-6Al-4V, so the chip width can be maintained constant without modifying the path geometry. A singularity in the experimental stage was to mill an Archimedes spiral groove instead of the conventional straight grooves. This made it possible to obtain a concave wall as well as a convex one and to optimize the amount of material used. The time efficiency compared to a constant feed, was slightly superior to 20%, reducing tool wear also. These techniques require milling machines with high mechanical and kinematic performance, as well as the absence of clearance between joints and a high acceleration capacity.

scholarly journals Modeling of Position-, Tool- and Workpiece-Dependent Milling Machine Dynamics

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Christian Brecher ◽  
Marcel Fey ◽  
Matthias Daniels
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Dynamic Properties ◽  
Major Effect ◽  
Modeling Framework ◽  
Milling Tool ◽  
Milling Machines ◽  
Engagement Process ◽  
Coupling Approach ◽  
Interpolation Strategy

AbstractDepending on the machine design, milling machines can show a significant variation of their dynamic properties with respect to the axes configurations, in particular at high speed spindle rotations and high feedrates. Moreover, the workpiece and the milling tool are critical parts of the machine tool and can have a major effect on the dynamic properties. Certain combinations of milling tool,workpiece, tool engagement, process parameters and axes configurations can come along with undesired forced or self-excited vibrations. So far, planning of milling processes usually does not account for these unwanted vibrations. The focus of this paper is to present a modeling framework, which accounts for the abovementioned influences via simulation. The dynamic properties of various workpieces and tools as well as the dynamic properties for many different axes configurations are stored in databases. Based on these databases, the dynamics of any given machine tool configuration can be simulated efficiently based on a substructure coupling approach and an interpolation strategy.

AQUAMET 22

Alloy Digest ◽  
1977 ◽  
Vol 26 (4) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Physical Properties ◽  
Nickel Alloys ◽  
Heat Treating ◽  
Advanced Materials ◽  
High Nickel ◽  
Better Than

Abstract AQUAMET 22 is an austenitic stainless steel with an outstanding combination of strength, toughness and corrosion resistance. Its corrosion resistance is equal to or better than any other boat shafting material, even better than most high-nickel alloys. It is the best material available for pleasure both shafts, considering that pleasure boats spend much of their time tied up at docks where corrosion factors may be highest. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SS-338. Producer or source: Armco Steel Corporation, Advanced Materials Division.

scholarly journals Identification of Technological Parameters of Ni-Alloys When Machining by Monolithic Ceramic Milling Tool

2017 ◽  
Vol 14 (2) ◽  
pp. 14-18
Author(s):  
Andrej Czán ◽  
Ondrej Kubala ◽  
Igor Danis ◽  
Tatiana Czánová ◽  
Jozef Holubják ◽  
...  
Keyword(s):  
Surface Quality ◽  
Nickel Alloys ◽  
Cutting Conditions ◽  
Technological Parameters ◽  
Machined Surface ◽  
Analysis And Evaluation ◽  
Ni Alloys ◽  
Milling Tool ◽  
Conventional Coating

Abstract The ever-increasing production and the usage of hard-to-machine progressive materials are the main cause of continual finding of new ways and methods of machining. One of these ways is the ceramic milling tool, which combines the pros of conventional ceramic cutting materials and pros of conventional coating steel-based insert. These properties allow to improve cutting conditions and so increase the productivity with preserved quality known from conventional tools usage. In this paper, there is made the identification of properties and possibilities of this tool when machining of hard-to-machine materials such as nickel alloys using in airplanes engines. This article is focused on the analysis and evaluation ordinary technological parameters and surface quality, mainly roughness of surface and quality of machined surface and tool wearing.

scholarly journals On Vibration Joint Time-Frequency Investigations of CNC Milling Machines for Tool Trajectory Task Conformity Estimation

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Silviu Nastac
Keyword(s):  
Spectral Characteristics ◽  
Experimental Tests ◽  
Vibration Monitoring ◽  
Cnc Milling ◽  
Cnc Machine ◽  
Shape Accuracy ◽  
Time Frequency ◽  
Milling Tool ◽  
Milling Machines ◽  
Acceleration Signals

This study deals with estimation of milling shape accuracy and trajectory conformity for small CNC 3D milling machines, based on vibration monitoring during the regular working cycles. The author made a large number of experimental tests, acquiring the acceleration signals, both on the milling tool-holder and on the bed frame. In order to evaluate the appropriate spectral characteristics of different machine parts and their weights on equipment dynamics, it was analyzed both the complete and the partial working cycle (such as forward tool motion, with or without effective milling, with or without tool driving, exclusively the milling cutter transitory/stabilized regime) for different basic milling shapes. The acceleration signals were jointly time-frequency investigated in order to evaluate specific spectral indicators related to the real motion characteristic of milling tool. It was used short time fast Fourier transform (STFFT) and Hough transform (HT) algorithms, along with stochastic evaluation of signal parameters, within time and frequency domains. The results reveal an accurate correlation between the specific transitory dynamics of the machine and the imposed milling shape. Main implications of the results within this analysis involve the noninvasive and facile investigation for milling errors of the CNC machine, conformity of tool head trajectory, identification of potential failure source, or damaged machine part.

Robot Grinding and Finishing of Cast Iron Stamping Dies

1992 ◽  
Vol 114 (1) ◽  
pp. 132-140 ◽  
Author(s):  
D. E. Whitney ◽  
E. D. Tung
Keyword(s):  
Cast Iron ◽  
Taguchi Method ◽  
Closed Loop ◽  
End Milling ◽  
Surface Profile ◽  
Feed Speed ◽  
Tool Marks ◽  
Position Accuracy ◽  
Stamping Dies ◽  
Milling Tool

This paper describes a method for finishing cast iron stamping dies. The task is to remove tool marks in the form of grooves and cusps left by a ball-end milling tool. The bottoms of the grooves represent the desired final surface profile. The method consists of using a closed-loop force-controlled robot with a flexible grinding disk coupled to a means for measuring the height of the partially ground cusps. Measurement is particularly easy, accurate, and sensitive if the tops of the partially ground cusps are flat, a condition that is not easy to obtain; otherwise accurate measurement is a chore. The Taguchi method is used to determine process parameters (grinding grit size, feed speed, disk speed, disk inclination angle, etc.) that yield flat tops. This grinding strategy has proven successful. A smooth, regular, and accurate final shape is obtained in spite of the relatively poor position accuracy of the robot. The measurement strategy has not been implemented yet but it appears feasible based on preliminary experiments.

scholarly journals Geometric accuracy of corners after milling operation of aluminum alloys

Mechanik ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 862-864
Author(s):  
Kamil Anasiewicz
Keyword(s):  
Feed Speed ◽  
Geometric Accuracy ◽  
Technological Parameters ◽  
Correct Process ◽  
Milling Tool ◽  
Milling Operation ◽  
Engagement Angle ◽  
The Right ◽  
Aluminum Alloy 7075 ◽  
The Relationship

The study comparing a geometry of the inner corners after milling operation of aluminum alloy 7075 elements was conducted. The influence of changes of technological parameters and types of treatment on the geometric accuracy of the samples was investigated. The correct process of corner milling involves the need to select the right feed speed as well as the correct engagement angle of the milling tool. Corner milling is problematic due to the increase of engagement angle in their area. This makes it much more difficult to perform stable machining and adversely affects the surface accuracy and geometry of the concave corners. The tests using various strategies and technological parameters for milling corners with variable opening angles were carried out. When analyzing the obtained results, conclusions were formulated indicating the relationship between the change of selected technological parameters of milling in the corners and the geometric accuracy of the samples tested.

APPROXIMATION ALGORITHM FOR MULTIPLE-TOOL MILLING

2001 ◽  
Vol 11 (03) ◽  
pp. 339-372 ◽  
Author(s):  
SUNIL ARYA ◽  
SIU-WING CHENG ◽  
DAVID M. MOUNT
Keyword(s):  
Approximation Algorithm ◽  
Computer Aided Design ◽  
Minimum Cost ◽  
Cnc Milling ◽  
Automated Generation ◽  
Polynomial Time Approximation Algorithm ◽  
Milling Tool ◽  
Milling Machines ◽  
Aided Design ◽  
Milling Tools

Milling is the mechanical process of removing material from a piece of stock through the use of a rapidly spinning circular milling tool in order to form some desired geometric shape. An important problem in computer-aided design and manufacturing is the automated generation of efficient milling plans for computerized numerically controlled (CNC) milling machines. Among the most common milling problems is simple 2-dimensional pocket milling: cut a given 2-dimensional region down to some constant depth using a given set of milling tools. Most of the research in this area has focused on generating such milling plans assuming that the machine has a tool of a single size. Since modern CNC milling machines typically have access to a number of milling tools of various sizes and the ability to change tools automatically, this raises the important optimization problem of generating efficient milling plans that take advantage of this capability to reduce the total milling time. We consider the following multiple-tool milling problem: Given a region in the plane and a set of tools of different sizes, determine how to mill the desired region with minimum cost. The problem is known to be NP-hard even when restricted to the case of a single tool. In this paper, we present a polynomial-time approximation algorithm for the multiple-tool milling problem. The running time and approximation ratio of our algorithm depend on the simple cover complexity (introduced by Mitchell, Mount, and Suri) of the milling region.

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

Biomimetic materials: An introduction

1992 ◽  
Vol 50 (2) ◽  
pp. 1020-1021 ◽  
Author(s):  
M. Sarikaya ◽  
J. T. Staley ◽  
I. A. Aksay
Keyword(s):  
Self Assembly ◽  
Structural Control ◽  
Hierarchical Structures ◽  
Ceramic Composites ◽  
Advanced Materials ◽  
Length Scale ◽  
Spider Webs ◽  
Biomimetic Materials ◽  
Synthetic Materials ◽  
All Ceramic

Biomimetics is an area of research in which the analysis of structures and functions of natural materials provide a source of inspiration for design and processing concepts for novel synthetic materials. Through biomimetics, it may be possible to establish structural control on a continuous length scale, resulting in superior structures able to withstand the requirements placed upon advanced materials. It is well recognized that biological systems efficiently produce complex and hierarchical structures on the molecular, micrometer, and macro scales with unique properties, and with greater structural control than is possible with synthetic materials. The dynamism of these systems allows the collection and transport of constituents; the nucleation, configuration, and growth of new structures by self-assembly; and the repair and replacement of old and damaged components. These materials include all-organic components such as spider webs and insect cuticles (Fig. 1); inorganic-organic composites, such as seashells (Fig. 2) and bones; all-ceramic composites, such as sea urchin teeth, spines, and other skeletal units (Fig. 3); and inorganic ultrafine magnetic and semiconducting particles produced by bacteria and algae, respectively (Fig. 4).

Comparison of ultra high resolution immersion lens CFESEM and TEM for imaging of semiconductor devices

1990 ◽  
Vol 48 (4) ◽  
pp. 622-623
Author(s):  
Terrence Reilly ◽  
Al Pelillo ◽  
Barbara Miner
Keyword(s):  
High Resolution ◽  
Sample Preparation ◽  
Cross Sections ◽  
Semiconductor Devices ◽  
Ion Milling ◽  
Observation Area ◽  
Transmission Electron ◽  
Milling Machines ◽  
Resolution Imaging ◽  
Electron Microscopes

The use of transmission electron microscopes (TEM) has proven to be very valuable in the observation of semiconductor devices. The need for high resolution imaging becomes more important as the devices become smaller and more complex. However, the sample preparation for TEM observation of semiconductor devices have generally proven to be complex and time consuming. The use of ion milling machines usually require a certain degree of expertise and allow a very limited viewing area. Recently, the use of an ultra high resolution "immersion lens" cold cathode field emission scanning electron microscope (CFESEM) has proven to be very useful in the observation of semiconductor devices. Particularly at low accelerating voltages where compositional contrast is increased. The Hitachi S-900 has provided comparable resolution to a 300kV TEM on semiconductor cross sections. Using the CFESEM to supplement work currently being done with high voltage TEMs provides many advantages: sample preparation time is greatly reduced and the observation area has also been increased to 7mm. The larger viewing area provides the operator a much greater area to search for a particular feature of interest. More samples can be imaged on the CFESEM, leaving the TEM for analyses requiring diffraction work and/or detecting the nature of the crystallinity.

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