Intelligent Modelling and Multi-Objective Optimisation of Laser Beam Cutting of Nickel Based Superalloy Sheet

2013 ◽  
Vol 3 (2) ◽  
pp. 1-16 ◽  
Author(s):  
Amit Sharma ◽  
Vinod Yadava ◽  
K. B. Judal
Keyword(s):  
Laser Beam ◽  
Process Parameters ◽  
Pulse Width ◽  
Thin Sheet ◽  
Cutting Speed ◽  
Pulse Frequency ◽  
Good Prediction ◽  
Ann Model ◽  
Nsga Ii ◽  
Nickel Based Superalloy

In the present study, a novel technique, namely, evolutionary non-dominated sorting genetic algorithm-II (NSGA-II) was used in conjunction with developed artificial neural network (ANN) model to select optimal process parameters for achieving the better process performance in LBC. First, ANN with backpropagation algorithm was used to model the LBC of nickel based superalloy sheets. The input process parameters taken were oxygen pressure, pulse width, pulse frequency and cutting speed. The performance characteristics of interest in nickel based superalloy thin sheet cutting are average kerf taper and surface roughness. The ANN model was trained and tested using the experimental data obtained through experimentation on pulsed Nd-YAG laser beam machining system. The 4-10-11-2 backpropagation architecture was found more accurate and generalized for given problem with good prediction capability. The results show that the developed modelling and optimization tool is effective for process parameter optimization in LBC process. The optimization of the process suggests that for achieving high cut quality characteristics the pulse width, pulse frequency and cutting speed are set to lower limit within the available range and gas pressure is set to a level which is sufficient to remove the molten metal from the kerf.

Laser Trepan Drilling of Monel k-500 Superalloy in Low Power Laser Beam Machining

2021 ◽  
pp. 137-159
Author(s):  
D. Pramanik ◽  
N. Roy ◽  
A. S. Kuar ◽  
S. Sarkar ◽  
S. Mitra ◽  
...  
Keyword(s):  
Laser Beam ◽  
Process Parameters ◽  
Focal Point ◽  
Average Power ◽  
Cutting Speed ◽  
Pulse Frequency ◽  
Laser Beam Machining ◽  
Proposed Model ◽  
Laser Trepan Drilling ◽  
Point Distance

In the field of micro processing of materials, laser has great importance as a source of heat and for its ability to deliver a coherent beam. The use of 50-watt average power for through-hole is impossible to achieve good quality drilling of the metal sheet upto 2 mm thickness. But the use of unique parameter sawing angle and constant focal point distance plays a significant role on hole diameter and circularity in laser trepan drilling. In the present research study, laser trepan drilling is investigated through multi diode pulsed fiber laser beam machining. Experimental analysis based on central composite design (CCD) of response surface methodology (RSM) has been fulfilled to find out the mathematical model. A study of the effect of sawing angle with other process parameters such as cutting speed, power, duty cycle, and pulse frequency on overcut bottom diameter and circularity at bottom for a monel k-500 has been conducted. Experimental validation of the proposed model shows that desired hole quality can be obtained by optimization of controllable of suitable process parameters.

Parametric Analysis of Laser Beam Percussion Drilling for Thin Titanium Alloy Sheet Using Yb: Yag Fiber Laser

2021 ◽  
pp. 1-24
Author(s):  
Mohit Singh ◽  
Sanjay Mishra ◽  
Vinod Yadava ◽  
J. Ramkumar
Keyword(s):  
Laser Beam ◽  
Fiber Laser ◽  
Pulse Width ◽  
Peak Power ◽  
Laser Pulses ◽  
Pulse Frequency ◽  
Alloy Sheet ◽  
Power Pulse ◽  
The Individual ◽  
Percussion Drilling

Laser beam percussion drilling (LBPD) can create high density holes in aerospace materials with the repeated application of laser pulses at a single spot. In this study, one-parameter-at-a-time approach has been used to investigate the individual effect of peak power, pulse width and pulse frequency on geometrical accuracy and metallurgical distortion during LBPD of 0.85[Formula: see text]mm thick Ti–6Al–4V sheet using 200[Formula: see text]W Yb:YAG fiber laser. It has been found that the output parameters behave differently at the higher and lower values of a particular input process. The increase of pulse width from 1 to 1.50[Formula: see text]ms increases hole taper by 20% whereas the same corresponding change from 1.50 to 2.00[Formula: see text]ms reduces the taper by 20%. The increase of pulse frequency from 10 to 50[Formula: see text]Hz reduces hole circularity by 40% but the same proportionate change from 50 to 90[Formula: see text]Hz reduces circularity by 79%. Increase of peak power from 1.70 to 2.0[Formula: see text]kW increases hole taper by 8% but the corresponding increase from 2 to 2.30[Formula: see text]kW is 143%.

Optimization of process parameters of Nd:YAG laser microgrooving of Al2TiO5 ceramic material by response surface methodology and artificial neural network algorithm

2007 ◽  
Vol 221 (8) ◽  
pp. 1341-1350 ◽  
Author(s):  
D Dhupal ◽  
B Doloi ◽  
B Bhattacharyya
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Response Surface Methodology ◽  
Predictive Model ◽  
Nd:Yag Laser ◽  
Pulse Width ◽  
Cutting Speed ◽  
Pulse Frequency ◽  
Pulsed Nd:Yag Laser ◽  
Lamp Current

The high-intensity pulsed Nd:YAG laser has the capability to produce both deep grooves and microgrooves on a wide range of engineering materials such as ceramics, composites, and diamond. The micromachining of ceramics is highly demanded in industry because of its wide and potential uses in various fields such as automobile, electronic, aerospace, and biomedical engineering. Engineering ceramic, i.e. aluminium titanate (Al2TiO5), has tremendous application in the automobile and aero-engine industries owing to its excellent thermal properties. The present paper deals with the artificial neural network (ANN) and response surface methodology (RSM) based mathematical modelling and also an optimization analysis of the machining characteristics of the pulsed Nd:YAG laser during the microgrooving operation on Al2TiO5. The experiments were planned and carried out based on design of experiments (DOE). Lamp current, pulse frequency, pulse width, assist air pressure, and cutting speed were considered as machining process parameters during the pulsed Nd:YAG laser microgrooving operation and these parameters were also utilized to develop the ANN predictive model. The response criteria selected for optimization were upper width, lower width, and depth of the trapezoidal microgroove. The optimal process parameter settings were obtained as an assist air pressure of 1.2944 kgf/cm2, lamp current of 19.3070A, pulse frequency of 1.755 kHz, pulse width of 5.7087 per cent of duty cycle, and cutting speed of 10mm/s for achieving the desired upper width, lower width, and depth of the laser microgroove. The output of the RSM optimal data was validated through experimentation and the ANN predictive model. A good agreement is observed between the results based on the ANN predictive model and the actual experimental observations.

scholarly journals Effect of Process Parameters on the Quality of Laser-Cut Stainless Steel Thin Plates

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1224
Author(s):  
Irene Buj-Corral ◽  
Lluís Costa-Herrero ◽  
Alejandro Domínguez-Fernández
Keyword(s):  
Process Parameters ◽  
Laser Cutting ◽  
Pulse Width ◽  
High Speed ◽  
Linear Models ◽  
Dimensional Accuracy ◽  
Pulse Frequency ◽  
Thin Plates ◽  
Dimensional Error ◽  
Frequency Pulse

At present, laser cutting is currently employed to cut metallic plates, due to their good finish and dimensional quality, as well as because of the flexibility of the process to obtain different shapes. In the present paper, surface roughness, dimensional accuracy, and burr thickness of thin plates of 0.8 mm are studied as functions of different process parameters: pulse frequency, pulse width, and speed. Eight different experiments were performed according to a full 23 factorial design, with two replicates each. Square specimens of 10 mm × 10 mm were cut. Arithmetical mean roughness Ra was measured with a contact roughness meter, and the dimensions and burr thickness with a micrometer. Ra values ranged between 1.89 and 3.86 µm, dimensional error values between 0.22 and 0.93%, and burr thickness between 2 and 34 µm. Regression analysis was performed, and linear models were obtained for each response. Results showed that roughness depends mainly on frequency, on the interaction of frequency and pulse width and on pulse width. The dimensional error depends on pulse width, frequency, and the interaction between pulse width and speed. Burr thickness is influenced by frequency, pulse width, and the interaction between frequency and speed. Multi-objective optimization showed that, in order to simultaneously minimize the three responses, it is recommended to use high frequency (80 Hz), high pulse width (0.6 ms), and high speed (140 mm/min). The present study will help to select appropriate laser cutting conditions in thin plates, in order to favor good surface finish and dimensional accuracy, as well as low burr thickness.

scholarly journals Modeling of hole geometrical features in laser drilling of AISI316L sheet

2021 ◽  
Author(s):  
Satish Namdev ◽  
◽  
Anand Pandey ◽  
Arun Kumar Pandey ◽  
◽  
...  
Keyword(s):  
Laser Beam ◽  
Cutting Speed ◽  
Pulse Frequency ◽  
Machining Process ◽  
Geometrical Features ◽  
Input Parameters ◽  
Micro Drilling ◽  
Bottom Side ◽  
Experimental Trials

Micro-drilling of AISI316L is very challenging task. Unconventional machining process may be used for such type of operation. Laser beam drilling is a best for micro drilling. High thermal energy and converging-diverging property of laser beam affects the quality of laser drilled holes. In present work Nd:YAG laser beam has been used and investigate effects of laser input parameters on responses. To minimize number of experiments, get extreme information for experimental trials. Central composite rotatable design approach has been adopted. Analysis of variance is used to find reliable input parameters, are affecting responses. From this paper, it is found that current and gas pressure are significant for hole circularity at top. Current and pulse frequency are significant for bottom side circularity. Current and cutting speed are significant parameter for hole taper.

scholarly journals Experimental Investigation and Performance Analysis of Ceramic Inserts in Laser Assisted Turning of Waspaloy

2018 ◽  
Vol 237 ◽  
pp. 01003 ◽  
Author(s):  
Martyna Wiciak ◽  
Tadeusz Chwalczuk ◽  
Agata Felusiak
Keyword(s):  
Tool Wear ◽  
Laser Beam ◽  
Tool Life ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Machining Performance ◽  
Heat Resistant Alloy ◽  
Nickel Based Superalloy ◽  
And Performance ◽  
Laser Assisted Turning

In this paper, the influence of laser assisted turning of hard-to-cut nickel-based superalloy on tool cutting ability was presented. The conducted research involved the machining performance along with tool life of ceramic inserts during turning of heat-resistant alloy under a trade name Waspaloy. The ceramic insert with geometry in accordance with the ISO – RPGX 120700 T01020 were applied during longitudinal turning with laser beam. The investigations has been completed with various cutting conditions such as laser power P, cutting speed vc, feed f and depth of cut ap. In order to determine the relations between the tool wear and cutting time, the tool life T has been selected. The increment of tool wear was correlated with the change of vibration signals and the critic points of tool wear was presented. In addition, the shape and form of chip was evaluated based on macroscopic observation and SEM analyses. The conducted research was primarily focused on effective application of ceramic inserts during turning Waspaloy with laser beam and comparison this technology with conventional machining.

scholarly journals Multi-objective Optimization of Kerf-taper and Surface-roughness Quality Characteristics for Cutting-operation On Coir and Carbon Fibre Reinforced Epoxy Hybrid Polymeric Composites During CO2-Pulsed Laser-cutting Using RSM

2021 ◽  
Author(s):  
Yadvinder Singh ◽  
Jujhar Singh ◽  
Shubham Sharma ◽  
Vivek Aggarwal ◽  
Catalin I. Pruncu
Keyword(s):  
Carbon Fibre ◽  
Laser Cutting ◽  
Pulse Width ◽  
Cutting Speed ◽  
Pulse Frequency ◽  
Quality Characteristics ◽  
Gas Pressure ◽  
Coir Fibre ◽  
Kerf Taper ◽  
Cut Quality

AbstractCurrent research focuses on optimizing various quality characteristics for kerf geometry generated through laser cutting of Coir fibre/carbon fibre/epoxy resin hybrid composite adjacent to straight cut profile employing pulsed CO2 laser system. The Kerf taper (KT) and the Surface roughness (SR) are the main quality parameters discussed. Dependent on significant process parameters, namely gas pressure, cutting speed, pulse frequency and pulse width predictive models were developed. In accordance with Taguchi's L9 orthogonal array (OA), the cutting trials are designed. Process-parametric optimization was performed using Response Surface Methodology (RSM). Furthermore, experiments were performed to obtain experimental data for the analysis of cut quality features. The impact of the input variables on the response characteristics is also explored. The morphological characterizations have been performed to analysis the effect of machining-variables and cut-quality for the top and bottom kerf widths with various laser cutting variables in the pulse laser-cutting of Coir-fibre/carbon-fibre/epoxy-resin hybrid composite. For SR and KT, the developed second order surface response model was found very successful. The optimal levels of cutting variables for KT are established at Gas pressure-6 N/mm2, pulse width-2.04 ms, cutting speed-8.01 mm/s, pulse frequency-15 Hz, for sample A1, Gas pressure-5.47 N/mm2, pulse width-2.5 ms, cutting speed-8.81 mm/s, pulse frequency-8.43 Hz, for sample A2, Gas pressure-3.85 N/mm2, pulse width-1.5 ms, cutting speed-9.06 mm/s, pulse frequency-5 Hz, for sample A3 additionally for SR Gas pressure-2 N/mm2, pulse width-1.5 ms, cutting speed-7 mm/s, pulse frequency-5 Hz, for sample A1, Gaspressure-2.36 N/mm2, pulse width-1.5 ms, cutting speed-7 mm/s, pulse frequency-15 Hz, for sample A2, Gaspressure-6 N/mm2, pulse width-1.5 ms, cutting speed-11 mm/s, pulse frequency-8.73 Hz, for sample A3. Regression results and linear and square impact of laser cutting variables have been revealed to be important to validate the model.

A Study of Fiber Laser Micro-Grooving of 316L Stainless Steel at Different Temperatures

2021 ◽  
pp. 251659842098436
Author(s):  
A. Sen ◽  
B. Doloi ◽  
B. Bhattacharyya
Keyword(s):  
Stainless Steel ◽  
Fiber Laser ◽  
Process Parameters ◽  
Laser Power ◽  
Room Temperature ◽  
316L Stainless Steel ◽  
Cutting Speed ◽  
Pulse Frequency ◽  
Different Temperatures ◽  
Haz Width

The present article deals with the generation of micro-grooves on 316L stainless steel (SS) by a nanosecond pulsed fiber laser system. Fabrication of micro-grooves on 316L SS has immensely contributed to the biomedical and automotive industries through improving the mechanical, lubrication, and corrosion resistance properties. In the present work, the considered process parameters are the preheating temperature (100°C and 200°C), along with the room temperature (24°C), cutting speed, sawing angle, pulse frequency, and laser power. The ranges of cutting speed and sawing angle are 0.1–1.1 mm s−1 and 0.1°–1°, respectively. Besides, pulse frequency and laser power vary from 55 kHz to 85 kHz and from 15 W to 45 W, respectively. The constant parameters are the pulse width of 99% and assist air pressure of 6 kgf cm−2. The variable parameters for the analysis are cut width and heat-affected zone (HAZ) width. The article aims to showcase a comprehensive study of fiber laser process parameters at different temperatures (preheated condition and room temperature) with variable sawing angles to produce better process control and bring about each considered process parameter’s critical value. The experimental results show that higher dimensions of cut width and HAZ width are observed at 200°C with the increment of sawing angle and laser power, compared to other temperatures. With the increment of cutting speed and laser power, the HAZ width tends to rise sharply. A significant drop in cut width and HAZ width dimensions is observed with the increment in pulse frequency for any temperature.

scholarly journals Optimization of Process Parameters of Laser Cladding 304L Alloy Powder Based on Orthogonal Experiment

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Linsen SHU ◽  
Bo WANG ◽  
Yayin HE
Keyword(s):  
Laser Cladding ◽  
Process Parameters ◽  
Alloy Powder ◽  
Pulse Width ◽  
Pulse Current ◽  
Orthogonal Experiment ◽  
Pulse Frequency ◽  
Optimal Combination ◽  
Optimal Process ◽  
Cladding Layer

In order to find the optimal combination of process parameters for laser cladding 304L alloy powder on the surface of 45 steel, a combination method of single factor test and multi-factor orthogonal experiment was used to perform the single pulse laser cladding experiment. The effects of process parameters (pulse current A, pulse width B, pulse frequency C,defocus distance D, scan velocity E) on the morphology and performance of cladding layer was studied by range analysis, and the optimal combination of cladding parameters is calculated by fuzzy comprehensive evaluation. The results show that different process parameters have different effects on the morphology of the cladding layer and scanning velocity E and defocus distance D are the most important influencing factor of cladding morphology. The effect on cladding width is D> C > A > B > E and the effect on cladding height is E > A > C > D > B. The optimal combination of cladding width is A4B4C4D4E2. The optimal combination of cladding high is A2B1C1D4E1. The comprehensive optimal process parameters are pulse current 210A, pulse width 3.6ms, pulse frequency 16Hz, defocus distance +10mm and scanning speed 240mm/min. The average hardness of the cladding layer, melting pool, heat-affected zone and substrate under the optimal process parameters is 406.2 HV0.5, 470.8 HV0.5, 230.5HV0.5 and 202.0HV0.5, respectively. The 304L cladding layer on 45 steel surface is stable in width, height and surface quality under comprehensive optimal parameters.

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