Optimization Research of Process Parameters for Laser Cladding Valve Parts Based on Genetic Algorithm

2012 ◽  
Vol 229-231 ◽  
pp. 382-386
Author(s):  
Jian Bin Wang ◽  
Ji Shu Yin

The optimization research of process parameters for big power Laser cladding valve parts, is a research focus of modern surface hardening technology. The article discussed in detail for solving the optimum process parameters of Laser cladding for the selection approach of strategy of genetic algorithm, the quantitative relationship model was established between process parameters and the valve parts property using neural network method , which process parameters are laser power (P), scanning speed (V), powder feeding rate (G), scan spacing (D) and thickness ( ) etc., the best configuration program of Genetic Algorithm control parameters has been obtain by means of the parameters encoding、initial group setting、fitness function design,genetic operation design and algorithm control parameters setting. The optimization of process parameters is obtained to fit the Laser cladding technology by using genetic algorithm toolbox in the MATLAB environment, and the optimization goal of the valve parts property has also been achieved. Practice has proved that the optimal process parameters are correct by the genetic algorithm , and has a very good production practice guide.

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2061 ◽  
Author(s):  
Jiang Ju ◽  
Yang Zhou ◽  
Maodong Kang ◽  
Jun Wang

The mould foot roller is a key component of a continuous casting machine. In order to investigate the possibility of using laser cladding to repair mould foot roller, Fe-based powders and 42CrMo steel are used in this work. The laser cladding process parameters were optimized by orthogonal experiments. The chemical compositions, microstructure, properties of the cladding layer under the optimum process parameters, and substrate were systematically investigated by using optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), microhardness test, wear test, and salt spray corrosion test. The results indicate that the primary factor affecting the width and depth of the cladding layer is laser power. The scanning speed also has a significant effect on the height of the cladding layer. The optimum process parameters for repairing the mould foot roller are 2 kW laser power, 4 mm/s scanning speed, and 15 g/min feeding rate of powder. Along the depth direction of the cladding layer, the microstructure of the coating gradually transforms from plane crystal, cell grains, or dendrites to equiaxed grains. The matrix is mainly martensite with retained austenite; the eutectic phase is composed of netlike M2B, particulate M23(C,B)6, and M7(C,B)3 phase. The hardness of the cladding layer is significantly improved, about three times that of the substrate. The weight loss of the cladding layer is just half that of the substrate. Its wear resistance and corrosion resistance have been significantly improved. The work period of the laser cladding-repaired foot roller is much longer than for the surfacing welding-repaired one. In summary, laser cladding technology can increase the life of mould foot rollers.


Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 728 ◽  
Author(s):  
Yu ◽  
Sun ◽  
Huang ◽  
Wang ◽  
Wang ◽  
...  

This paper aimed to establish a nonlinear relationship between laser cladding process parameters and the crack density of a high-hardness, nickel-based laser cladding layer, and to control the cracking of the cladding layer via an intelligent algorithm. By using three main process parameters (overlap rate, powder feed rate, and scanning speed), an orthogonal experiment was designed, and the experimental results were used as training and testing datasets for a neural network. A neural network prediction model between the laser cladding process parameters and coating crack density was established, and a genetic algorithm was used to optimize the prediction results. To improve their prediction accuracy, genetic algorithms were used to optimize the weights and thresholds of the neural networks. In addition, the performance of the neural network was tested. The results show that the order of influence on the coating crack sensitivity was as follows: overlap rate > powder feed rate > scanning speed. The relative error between the predicted value and the experimental value of the three-group test genetic algorithm-optimized neural network model was less than 9.8%. The genetic algorithm optimized the predicted results, and the technological parameters that resulted in the smallest crack density were as follows: powder feed rate of 15.0726 g/min, overlap rate of 49.797%, scanning speed of 5.9275 mm/s, crack density of 0.001272 mm/mm2. Therefore, the amount of crack generation was controlled by the optimization of the neural network and genetic algorithm process.


2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744017
Author(s):  
Liang-Bo Ji ◽  
Fang Chen

Numerical simulation and intelligent optimization technology were adopted for rolling and extrusion of zincked sheet. By response surface methodology (RSM), genetic algorithm (GA) and data processing technology, an efficient optimization of process parameters for rolling of zincked sheet was investigated. The influence trend of roller gap, rolling speed and friction factor effects on reduction rate and plate shortening rate were analyzed firstly. Then a predictive response surface model for comprehensive quality index of part was created using RSM. Simulated and predicted values were compared. Through genetic algorithm method, the optimal process parameters for the forming of rolling were solved. They were verified and the optimum process parameters of rolling were obtained. It is feasible and effective.


2019 ◽  
Vol 13 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Ram Balak Mahto ◽  
Mukesh Yadav ◽  
Soumya Sasmal ◽  
Biswnath Bhunia

Background: Pectinase enzyme has immense industrial prospects in the food and beverage industries. </P><P> Objective: In our investigation, we find out the optimum process parameters suitable for better pectinase generation by Bacillus subtilis MF447840.1 using submerged fermentation. </P><P> Method: 2% (OD600 nm = 0.2) of pure Bacillus subtilis MF447840.1 bacterial culture was inoculated in sterile product production media. The production media components used for this study were 1 g/l of pectin, 2 g/l of (NH4)2SO4, 1 g/l of NaCl, 0.25 g/l of K2HPO4, 0.25 g/l of KH2PO4 and 1 g/l of MgSO4 for pectinase generation. We reviewed all recent patents on pectinase production and utilization. The various process parameters were observed by changing one variable time method. </P><P> Results: The optimum fermentation condition of different parameters was noticed to be 5% inoculums, 25% volume ratio, temperature (37°C), pH (7.4) and agitation rate (120 rpm) following 4 days incubation. </P><P> Conclusion: Maximum pectinase generation was noticed as 345 ± 12.35 U following 4 days incubation.


2018 ◽  
Vol 2 (3) ◽  
pp. 55 ◽  
Author(s):  
Piera Alvarez ◽  
M. Montealegre ◽  
Jose Pulido-Jiménez ◽  
Jon Arrizubieta

Laser Cladding is one of the leading processes within Additive Manufacturing technologies, which has concentrated a considerable amount of effort on its development. In regard to the latter, the current study aims to summarize the influence of the most relevant process parameters in the laser cladding processing of single and compound volumes (solid forms) made from AISI 316L stainless steel powders and using a coaxial nozzle for their deposition. Process speed, applied laser power and powder flow are considered to be the main variables affecting the laser cladding in single clads, whereas overlap percentage and overlapping strategy also become relevant when dealing with multiple clads. By setting appropriate values for each process parameter, the main goal of this paper is to develop a processing window in which a good metallurgical bond between the delivered powder and the substrate is obtained, trying simultaneously to maintain processing times at their lowest value possible. Conventional metallography techniques were performed on the cross sections of the laser tracks to measure the effective dimensions of clads, height and width, as well as the resulting dilution value. Besides the influence of the overlap between contiguous clads and layers, physical defects such as porosity and cracks were also evaluated. Optimum process parameters to maximize productivity were defined as 13 mm/s, 2500 W, 30% of overlap and a 25 g/min powder feed rate.


Author(s):  
Nehal Dash ◽  
Apurba Kumar Roy ◽  
Sanghamitra Debta ◽  
Kaushik Kumar

Plasma Arc Cutting (PAC) process is a widely used machining process in several fabrication, construction and repair work applications. Considering gas pressure, arc current and torch height as the inputs and among all possible outputs, in the present work Material Removal Rate and Surface Roughness would be considered as factors that determines the quality, machining time and machining cost. In order to reduce the number of experiments Design of Experiments (DOE) would be carried out. In later stages applications of Genetic Algorithm (GA) and Fuzzy Logic would be used for Optimization of process parameters in Plasma Arc Cutting (PAC). The output obtained would be minimized and maximized for Surface Roughness and Material Removal Rate respectively using Genetic Algorithm (GA) and Fuzzy Logic.


2012 ◽  
Vol 2012 (1) ◽  
pp. 000694-000701
Author(s):  
Zeliha YILMAZ ◽  
Murat PAK ◽  
Sema İMRAHORILYAS ◽  
Aylin ERSOY

Stabilization after the lithography process is crucial in order to prevent deformation of photoresist patterns by other thermal processes used in semiconductor production. UV hardening is capable of minimizing negative effects of thermal processes such as rounded shaped lines; line width widening or shrinkage and CD shift. The amount of UV energy absorbed and final process temperature are important process parameters; which effect directly the degree of cross-linking. So, this paper examines optimization of process parameters such as the ramp rate, which is the tangent of the temperature-time curve (°C/sec) and the final temperature. Also the ramp rate indicates the time; that wafer is exposed to the high degree of UV energy. Process parameters are optimised with respect to the improvement of etch selectivity, decrease of the CD shift. Profile photos have been taken with Scanning Electron Microscope. In the experiments, the novolak based i-line photoresist and ICON-7 as anti reflecting coating are used for the lithography process. Many variables have been taken into consideration while determining optimum process parameters. These are resist thickness, type of the surface layer of wafer, magnitude of the critical dimension (&gt;1 μm & &lt; 1 μm ) and the size of the open area on the reticle used during exposure.


Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 123 ◽  
Author(s):  
Matthew Benton ◽  
Mohammad Hossan ◽  
Prashanth Konari ◽  
Sanjeewa Gamagedara

Laser micromachining has emerged as a promising technique for mass production of microfluidic devices. However, control and optimization of process parameters, and design of substrate materials are still ongoing challenges for the widespread application of laser micromachining. This article reports a systematic study on the effect of laser system parameters and thermo-physical properties of substrate materials on laser micromachining. Three dimensional transient heat conduction equation with a Gaussian laser heat source was solved using finite element based Multiphysics software COMSOL 5.2a. Large heat convection coefficients were used to consider the rapid phase transition of the material during the laser treatment. The depth of the laser cut was measured by removing material at a pre-set temperature. The grid independent analysis was performed for ensuring the accuracy of the model. The results show that laser power and scanning speed have a strong effect on the channel depth, while the level of focus of the laser beam contributes in determining both the depth and width of the channel. Higher thermal conductivity results deeper in cuts, in contrast the higher specific heat produces shallower channels for a given condition. These findings can help in designing and optimizing process parameters for laser micromachining of microfluidic devices.


2019 ◽  
Vol 16 (1) ◽  
pp. 43-57 ◽  
Author(s):  
Reddy Sreenivasulu ◽  
Chalamalasetti SrinivasaRao

Abstract Burr formation during machining process is a vital role in the assembly lines, even though it is a non value added process but also care should be taken while machining due to non avoiding output generated at the end of material removal process. At present almost all manufacturing sectors faces lot of problems due to these issues and invest more money towards deburring still advanced manufacturing methods available. So, complete burr removal is not possible and only thing is reducing utmost by applying better optimizing techniques, to develop good mechanization methods, selecting optimum process parameters and their conditions. The aim this paper deals about research methods implemented by earlier authors on burr formation especially in drilling. The reason why the present authors selected the drilling is number of automotive and aircraft engineers struggling during structural building works because of these burrs wherever precise measurement needed. In this connection, the authors concentrate their study on previous researcher works related to investigations on experimentation, developing new theoretical mechanisms to minimize burrs, adapt a new technologies available to modify drill bit geometries such that improvement in the minimization of burrs. Finally found that research contributions by changing their drill bit geometry and cutting process parameters have been focused on utilizing the methodologies, changing time to time. In analyzing the performance characteristics with that of input process parameters, several mathematical and empirical models were developed by many researchers so far in their works. Efforts have been made in the direction of optimization of process parameters in drilling for minimizing burr size.


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