Dimensional accuracy optimization of the laser milling process

2007 ◽  
Author(s):  
Sabina Luisa Campanelli ◽  
Antonio Domenico Ludovico ◽  
Carmela Deramo
Keyword(s):  
Dimensional Accuracy ◽  
Milling Process ◽  
Laser Milling

An Experimental Investigation of the Laser Milling Process for Polycrystalline Diamonds

2011 ◽  
Vol 291-294 ◽  
pp. 810-815 ◽  
Author(s):  
Qi Wu ◽  
Jun Wang
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Polycrystalline Diamond ◽  
Milling Process ◽  
Depth Of Cut ◽  
Good Surface ◽  
Laser Milling ◽  
Cavity Profile ◽  
Profile Depth ◽  
Good Surface Finish

An experimental study of the pulsed laser milling process for a sintered polycrystalline diamond is presented. The characteristics and quality of the cavities machined with a Yd laser under different pulse energies, pulse overlaps, scan overlaps and numbers of passes are discussed, together with the effects of these parameters on the cavity profile, depth of cut and surface roughness. A statistical analysis is also presented to study the relationship between the process parameters and surface roughness. It shows that the optimum pulse overlap and pulse energy may be used to achieve good surface finish, whereas scan overlap and number of passes can be selected to improve the depth of cut without much effect on the surface finish.

Automatic Characterization of the Material Removal Rate in Laser Manufacturing of TiAl6V4 and Inconel 718

2009 ◽  
Author(s):  
Leonardo Orazi ◽  
Gabriele Cuccolini ◽  
Giovanni Tani
Keyword(s):  
Material Removal Rate ◽  
Inconel 718 ◽  
Material Removal ◽  
Numerical Models ◽  
Removal Rate ◽  
Industrial Applications ◽  
Milling Process ◽  
Laser Source ◽  
Automated Method ◽  
Laser Milling

In this paper a system for the automatic determination of the material removal rate during laser milling process is presented. “Laser milling” can be defined as an engraving process with a strictly controlled penetration depth. In industrial applications, when a new material have to be machined or a change in the system set-up occur the user has to perform a time-consuming experimental campaign in order to determine the correlation between the material removal rate and the process parameters. In these cases the numerical models present some limits due to the elevated calculation time requested to simulate the laser milling of industrial features. In the proposed system, based on a regression model approach, the empirical coefficients, that provide the material removal rate, are automatically generated by a specific software according to the different materials that have to be processed. A description of the automated method and the results obtained in engraving TiAl6V4 and Inconel 718 superalloy with a fiber laser are presented. The system can be adapted to every combination of material/laser source.

A Tool Deflection Compensation System for End Milling Accuracy Improvement

1998 ◽  
Vol 120 (2) ◽  
pp. 222-229 ◽  
Author(s):  
M. Y. Yang ◽  
J. G. Choi
Keyword(s):  
Feed Rate ◽  
Cutting Forces ◽  
End Milling ◽  
Dimensional Accuracy ◽  
Milling Process ◽  
Compensation System ◽  
Experimental Investigations ◽  
Tool Deflection ◽  
Surface Errors ◽  
Tool Deflections

In an effort to reduce machining surface errors due to tool deflection in the end milling process, methods regulating cutting forces have been implemented with online feed rate controls. Such schemes are able to improve the parts dimensional accuracy, but unfortunately they can exhibit undesirable aspects in which the alleviation of the cutting conditions deteriorates the productivity. In addition the frequent changes of the feed rate would spoil the surface quality. As a new approach to achieve the precision machining efficiently, this paper introduces a tool deflection compensation system. This compensation system is a computer controlled special tool adapter which is capable of measuring the cutting forces and minutely adjusting the position of the tool without interfacing with the NC controller of the milling machine. Such a system allows for on-line estimation of the tool deflections and reduction of the surface errors. Experimental investigations for typical shaped workpieces representing various end milling situations are performed to verify the ability of the system to suppress the surface errors due to tool deflections in more productive machining condition.

Chatter Investigation in Titanium Milling

2014 ◽  
Vol 1019 ◽  
pp. 318-324
Author(s):  
Jean Claude Fwamba ◽  
Lerato Crescelda Tshabalala ◽  
Cebo Philani Ntuli ◽  
Isaac Tlhabadira
Keyword(s):  
Feed Rate ◽  
End Milling ◽  
Processing Condition ◽  
Weight Ratio ◽  
Dimensional Accuracy ◽  
Milling Process ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Performance ◽  
Chatter Vibrations

<span><p align="LEFT"><span><span style="font-family: Times New Roman;" face="Times New Roman">Titanium and its alloys have been experiencing extensive development over the past few decades. They have found wide applications in the aerospace, biomedical and automotive industries owing to their good strength-to-weight ratio and high corrosion resistance. Machining performance is often limited by chatter vibrations at the tool-workpiece interface. Chatter is an abnormal tool behaviour which is one of the most critical problems in the machining process and must be avoided to improve the dimensional accuracy and surface quality of the finished product. This research aims at investigating chatter trends in the end milling process and to identify machine parameters that have effects on chatter during machining. The machine parameters investigated include axial feed rate, spindle revolute speed and depth of cut. In this research, experimental data was collected using sensors to analyze the existence of chatter vibrations on each processing condition. This research showed that the combination of the machine parameters, feed rate and spindle speed within certain proportions has an influence on machine vibrations during end milling and if not managed properly, may lead to chatter. </span></span></p> <p align="LEFT"></p>

Laser milling: Modelling crater and surface formation

2006 ◽  
Vol 220 (11) ◽  
pp. 1685-1696 ◽  
Author(s):  
T Dobrev ◽  
S S Dimov ◽  
A J Thomas
Keyword(s):  
Numerical Technique ◽  
Target Material ◽  
Milling Process ◽  
Laser Material ◽  
Surface Formation ◽  
Laser Ablation Process ◽  
Laser Milling ◽  
Change Of State ◽  
Machining Strategies ◽  
Physical Phenomena

In pulsed laser-material removal systems, it is very important to understand the physical phenomena that take place during the laser ablation process. A two-dimensional, theoretical model is developed to investigate the crater formation on a metal target by a microsecond laser pulse. The model takes into account the absorption of the laser light and heating and vapourization of the target, including an adjustment to compensate for the change of state. A simple numerical technique is employed to describe the major physical processes taking part in the laser milling process. The temperature distribution in the target material during the pulse duration is analysed. The effect of the laser fluence on the resulting crater is investigated in detail. The proposed simulation model was validated experimentally for laser-material interactions between a microsecond Nd:YAG laser (λ = 1064 nm) and two different tooling materials. The measured crater depths are in agreement with the model. In addition, an analytical approach is discussed for studying the effects of crater profiles and different machining strategies on the surface formation and the resulting surface quality during the laser milling process. This approach can be employed as a tool for optimizing the process and thus broaden its use in a range of microstructuring applications. The research reported in this paper contributes to a better understanding of microstructuring capabilities of the laser milling process.

Producing Three-Dimensional Shapes by Laser Milling

1990 ◽  
Vol 112 (4) ◽  
pp. 375-379 ◽  
Author(s):  
R. K. C. Hsu ◽  
S. M. Copley
Keyword(s):  
Carbon Dioxide ◽  
Laser Beam ◽  
Carbon Dioxide Laser ◽  
Three Dimensional ◽  
Milling Process ◽  
Model Material ◽  
Layer Plane ◽  
Uniform Thickness ◽  
Laser Milling ◽  
Focused Beam

A laser milling process employing a pulsed, carbon dioxide laser has been investigated using graphite as a model material. Material is removed by scanning the focused beam across the surface of the workpiece leaving behind a series of narrow, parallel, overlapping grooves. These grooves, together, constitute the removal of a thin layer of uniform thickness lying parallel to a layer plane. In order to remove layers bounded at the edge by upright walls perpendicular to the layer plane, the laser beam must be tilted with respect to the layer plane. Using this approach, it is possible to produce perpendicular steps and cylindrical surfaces.

Five-axis milling of sculptured surfaces of the turbine blade

2018 ◽  
Vol 90 (1) ◽  
pp. 146-157 ◽  
Author(s):  
Michal Gdula ◽  
Jan Burek ◽  
Lukasz Zylka ◽  
Marcin Plodzien
Keyword(s):  
Turbine Blade ◽  
Turbine Blades ◽  
Dimensional Accuracy ◽  
Milling Process ◽  
Radius Of Curvature ◽  
Sculptured Surfaces ◽  
Axis Orientation ◽  
Content Type ◽  
Five Axes ◽  
Toroidal Cutter

Purpose The purpose of this paper is to determine the influence of a toroidal cutter axis orientation and a variable radius of curvature of the machined contour of sculptured surface on the five-axes milling process. Simulation and experimental research performed in this work are aimed to determine the relationship between the parameters of five-axes milling process and the shape and dimensional accuracy of curved outline of Inconel 718 alloy workpiece. Design/methodology/approach A subject of research are sculptured surfaces of the turbine blade. Simulation research was performed using the method of direct mapping tools in the CAD environment. The machining research was carried out with the use of multi-axis machining center DMU 100 monoBLOCK DMG, equipped with rotating dynamometer to measure the components of the cutting force. To control the shape and dimensional accuracy, the coordinate measuring machine ZEISS ACCURA II was used. Findings In this paper, the effect of the toroidal cutter axis orientation and the variable radius of curvature of the machined contour on the parameters of five-axes milling process and the accuracy of the sculptured surfaces was determined. Practical implications Five-axes milling with the use of a toroidal cutter is found in the aviation industry, where sculptured surfaces of the turbine blades are machined. The results of the research allow more precise planning of five-axes milling and increase of the turbine blades accuracy. Originality/value This paper significantly complements the current state of knowledge in the field of five-axes milling of turbine blades in terms of their accuracy.

scholarly journals Effect of laser beam trajectory on pocket geometry in laser micromachining

2020 ◽  
Vol 10 (1) ◽  
pp. 830-838 ◽  
Author(s):  
Grzegorz Witkowski ◽  
Szymon Tofil ◽  
Krystian Mulczyk
Keyword(s):  
Laser Beam ◽  
Surface Condition ◽  
Experimental Tests ◽  
Laser Micromachining ◽  
Milling Process ◽  
Beam Trajectory ◽  
Laser Milling ◽  
Observation Methods ◽  
The Impact ◽  
Ablative Laser

AbstractThe article presents the problem of planning the laser beam trajectory for the laser micromachining process. The article concerns on the ablative laser micromachining issues. Different effects of laser beam trajectory on pocket geometry in laser micromachining were investigated. The results of experimental tests are presented. Based on the research, potential causes of different effects of the laser beam for various trajectories were formulated. Several different types of trajectories for the assumed shape were developed for the purposes of the research. Laser micromachining was performed with fixed parameters of the laser device using different trajectories. The article indicates the significant impact of the laser beam trajectory on the effect of interaction on matter during the laser milling process, which is not often mentioned in scientific reports. The article presents the basic geometrical measurements indicating the need to determine the leading of the laser beam. Studieswere conducted using the microscopic observation methods and interferometric methods for estimating the surface condition. The article indicates the need for extensive research focusing on the mechanism of the impact of the laser beam scan strategy on the effect on the material during ablative laser machining. The article summarizes the analysis and discussion of research results.

scholarly journals Chatter Detection in Milling Process Based on the Combination of Wavelet Packet Transform and PSO-SVM

2021 ◽  
Author(s):  
Qingzhen Zheng ◽  
Guangsheng Chen ◽  
Anling Jiao
Keyword(s):  
Wavelet Packet ◽  
Dimensional Accuracy ◽  
Vibration Signal ◽  
Pso Algorithm ◽  
Milling Process ◽  
Wavelet Packet Transform ◽  
Wavelet Packets ◽  
Limiting Factor ◽  
Novel Method ◽  
Traditional Approaches

Abstract Chatter has become the mainly limiting factor in the development of rapid and stable machining of machine tools, which seriously impacts on surface quality and dimensional accuracy of the finished workpiece. In this paper, a novel method of chatter recognition was proposed based on the combination of wavelet packet transform (WPT) and PSO-SVM in milling. The collected vibration signal was pre-processed by wavelet packet transform (WPT), and the wavelet packets with rich chatter information were selected and reconstructed. The selected wavelet packets can reduce the redundant noise and useless information. a combination of 10 time-domain and 4 frequency-domain feature parameters were obtained through calculating the reconstructed vibration signals. Compared to three methods of k-fold cross validation (k-CV), genetic algorithm (GA) and particle swarm optimization (PSO) to optimize the input parameters of SVM, the experiment results were shown that the PSO algorithm has is characterized by high accuracy. The proposed approach can recognize the stable, chatter and transition states more accurately than the other traditional approaches.

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