Optimizing the laser parameters to attain maximum hardness in nickel based hardfacing surfaces

2017 ◽  
Vol 26 (3-4) ◽  
pp. 113-125 ◽  
Author(s):  
S. Gnanasekaran ◽  
G. Padmanaban ◽  
V. Balasubramanian ◽  
Hemant Kumar ◽  
Shaju K. Albert

AbstractIn this investigation, an attempt has been made to optimize the laser hardfacing (LH) parameters such as power, powder feed rate (PFR), travel speed and defocusing distance to maximize hardness of Ni-based hardfacing surfaces. Statistical tools such as the design of experiments (DoE), analysis of variance (ANOVA) are used to develop the empirical relationship to predict the hardness of the deposits at the 95% confidence level. Response graphs and contour plots are constructed using response surface methodology (RSM) concept. From this investigation, it is found that the maximum hardness of 820.48 HV could be achieved for the deposit made using a power of 1314 W, PFR of 9 g/min, a travel speed of 366 mm/min, and a defocusing distance of 32 mm.

2013 ◽  
Vol 13 (1-2) ◽  
pp. 31-36
Author(s):  
Sadineni Rama Rao ◽  
G. Padmanabhan

AbstractElectrochemical machining (ECM) is increasing its importance in machining of metal matrix composites (MMC) due to some specific advantages which can be exploited during machining operation. In ECM the quality of the surface produced is also depends on the workpiece physical and electrical properties along with the process parameters like voltage, feed rate, electrolyte concentration, type of electrolyte, current, gap between electrodes etc. Therefore, in the present work the percentage of reinforcement of the particulates in the matrix is considered one of the process parameters along with the applied voltage, electrode feed rate and electrolyte concentration. A mathematical prediction model of the radial over cut (ROC) was developed using response surface methodology (RSM). The effects of electrochemical machining parameters on the Radial over cut were evaluated. The contour plots were drawn to study the effect of various process parameters and their interaction. In this work the predicted values and measured values are quite close to each other. Therefore, the developed model can be effectively used to predict the radial over cut on electrochemical machining of Al-B4C composites.


Author(s):  
L B Abhang ◽  
M Hameedullah

This paper utilizes the regression modeling in turning process of En-31 steel using response surface methodology (RSM) with factorial design of experiments. A first-order and second-order surface roughness predicting models were developed by using the experimental data and analysis of the relationship between the cutting conditions and response (surface roughness). In the development of predictive models, cutting parameters of cutting velocity, feed rate, depth of cut, tool nose radius and concentration of lubricants were considered as model variables, surface roughness were considered as response variable. Further, the analysis of variance (ANOVA) was used to analyze the influence of process parameters and their interaction during machining. From the analysis, it is observed that feed rate is the most significant factor on the surface roughness followed by cutting speed and depth of cut at 95% confidence level. Tool nose radius and concentration of lubricants seem to be statistically less significant at 95% confidence level. Furthermore, the interaction of cutting velocity/feed rate, cutting velocity/ nose radius and depth of cut/nose radius were found to be statistically significant on the surface finish because their p-values are smaller than 5%. The predicted surface roughness values of the samples have been found to lie close to that of the experimentally observed values.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
S. Gnanasekaran ◽  
Samson Jerold Samuel Chelladurai ◽  
T. Ramakrishnan ◽  
S Sivananthan ◽  
G. Padmanaban ◽  
...  

The nickel-based Colmonoy-5 hardfacing alloy is used to hard-face 316LN austenitic stainless steel components in fast reactors. The nominal composition (in wt%) was listed as follows: 0.01 C, 0.49 Si, 0.87 Mn, 17.09 Cr, 14.04 Ni, 2.56 Mo, 0.14 N, and balance Fe. Hardfacing is a technique of applying hard and wear-resistant materials to substrates that need abrasion resistance. The thickness of hardfacing deposit varies between 0.8 mm and 2 mm based on parameter combinations. In this study, laser hardfacing process parameters including laser power, powder feed rate, travel speed, and defocusing distance were optimized to reduce weight loss of laser hard-faced Ni-based deposit. The tribological characteristics of reactor-grade NiCr-B hard-faced deposits were investigated. The RSM technique was used to identify the most important control variables resulting in the least weight loss of the nickel-based alloy placed on AISI 316LN austenitic stainless steel. Statistical techniques like DoE and ANOVA are utilized. Changing the laser settings may efficiently track the weight loss of laser hard-faced nickel alloy surfaces. These are created using the response surface technique. The deposit produced with a laser power of 1314 W, powder feed rate of 9 g/min, travel speed of 366 mm/min, and defocusing distance of 32 mm had the lowest weight loss of 16.4 mg. Based on the F value, the powder feed rate is the major influencing factor to predict the hardness followed by power, travel speed, and defocusing distance.


2019 ◽  
Vol 38 (2019) ◽  
pp. 248-263 ◽  
Author(s):  
D. D. Deshmukh ◽  
V. D. Kalyankar

AbstractPlasma transferred arc welding (PTAW) is one of the outstanding overlay coating technique used in numerous industries including pressure vessel, automotive, chemical, nuclear, etc. owing to its superior characteristics, low dilution and high efficiency in the coating. In the present investigations, an effort is made to investigate the multitrack overlay deposition by PTAW on 16 mm thick 316 L plate by CO-Cr alloy. Samples are produced under different processing conditions, as per full factorial central composite design of experiment with preheating of 200°C by maintaining the interpass temperature 250 °C. Effects of transferred arc current, welding travel speed, powder feed rate, welding oscillation speed and stand-off distance on weld bead shape parameters comprising of width of deposition and reinforcement are presented and discussed based on experimental observations and fitted model. Relationship between the input process parameters with deposition characteristics is also presented in the form of regression equation. Lower current (100–120 A), intermediate travel speed (120–140 mm/min), intermediate powder feed rate (12–14 gms/min), lower oscillating speed (450–550 mm/min) and lower stand-off distance (6–8 mm) would give better deposition characteristics with minimum distortion, less residual stresses, no surface defects with strong metallurgical bond.


2020 ◽  
Vol 10 (3) ◽  
pp. 219-227
Author(s):  
Ali Behmaneshfar ◽  
Abdolhossein Sadrnia ◽  
Hassan Karimi-Maleh

Background: In recent years, the Design of Experiments (DOE) is used for removing pollutant from wastewater by nano-adsorbent. Some methods are Taguchi, Response Surface Methodology (RSM) and factorial design. The aim of this paper is to review different used methods of DOE in removing pollutant to suggest some notations to scholars. Methods: The reviewed papers were searched in Google Scholar, Scopus, and Web of Science randomly and categorized based on DOE methods. Results: Number of factors and responses in DOE for removing pollutants from wastewater are between 2-6 and 1-4, respectively. There are several computer software programs that provide simple use of these methods, such as Qualitek, Design Expert, Minitab, R and Matlab Programming. All models have a coefficient of determination R-sq more than 0.9. Conclusion: All the mentioned methods are appropriate because of the high R-sq value. Since the largest number of runs are used in RSM, it is not suitable for the experiments which are conducted by expensive materials and process. Furthermore, Design Expert and Minitab are the most popular software used by scholars in DOE methods for the removal of pollutant.


Aviation ◽  
2021 ◽  
Vol 25 (4) ◽  
pp. 268-277
Author(s):  
Volodymyr Dzyura ◽  
Pavlo Maruschak ◽  
Stoyan Slavov ◽  
Diyan Dimitrov ◽  
Dimka Vasileva

The basic regularities in the influence of processing parameters on the geometrical characteristics of the partially regular microreliefs, formed on the rotary body face surface, are established. Combinations of partially regular microreliefs are formed by using a contemporary CNC milling machine, and an advanced programing method, based on previously developed mathematical models. Full factorial experimental design is carried out, which consist of three factors, varied on three levels. Regression stochastic models in coded and natural form, which give the relations between the width of the grooves and the deforming force, feed rate and the pitch of the axial grooves, are derived as a result. Response surfaces and contour plots are built in order to facilitate the results analysis. Based on the dependencies of the derived regression stochastic models, it is found that the greatest impact on the width of the grooves has the magnitude of the deforming force,followed by the feed rate. Also, it is found that the axial pitch between adjacent toolpaths has the least impact on the width of the grooves. As a result of the full-factorial experiment, the average geometric parameters of the microrelief grooves were obtained on their basis. When used, these values will provide for the required value of the relative burnishing area of the surface with regular microreliefs, and, accordingly, the specified operational properties.


Author(s):  
Peter Kayode Farayibi

Laser deposition is an advanced manufacturing technology capable of enhancing service life of engineering components by hard-facing their functional surfaces. There are quite a number of parameters involved in the process and also desirable output characteristics. These output characteristics are often independently optimised and which may lead to poor outcome for other characteristics, hence the need for multi-objective optimisation of all the output characteristics. In this study, a laser deposition of Ti-6Al-4V wire and tungsten carbide powder was made on a Ti-6Al-4V substrate with a view to achieve a metallurgical bonded metal matrix composite on the substrate. Single clads were deposited with a desire to optimise the composite clad characteristics (height, width and reinforcement fraction) for the purpose of surface coating. Processing parameters (laser power, traverse speed, wire feed rate, powder feed rate) were varied, the experiment was planned using Taguchi method and output characteristics were analysed using principal component analysis approach. The results indicated that the parameters required for optimised clad height, width, and reinforcement fraction necessary for surface coating is laser power of 1800 W, traverse speed of 200 mm/min, wire feed rate 700 mm/min and powder feed rate of 30 g/min. The powder feed rate was found to most significantly contribute 43.99%, followed by traverse speed 39.77%, laser power 15.87% with wire feed rate having the least contribution towards the multi-objective optimisation. Confirmation results showed that clad width and reinforcement fraction were significantly improved by the optimised parameters. The multi-objective optimisation procedure is a useful tool necessary to identify the process factors required to enhance output characteristics in laser processing.


Author(s):  
Jorge Alejandro TORRES-OCHOA ◽  
Nadia Renata OSORNIO-RUBIO ◽  
Orlando CORTAZAR-MARTINEZ ◽  
Victor Alfonso MORALES-NIETO

In this work, the process for the formulation of flexible polyurethane foam is presented following a design of experiments for mixtures. The proportion of polyol, diisocyanate, and crosslinker was considered as factors. The response variables considered were foaming time and reaction temperature. The result of the experiments showed that there is an area where the foam formulation is better. This zone is closed with 5% crosslinker, 50% polyol, and 45% diisocyanate, in this formulation denser foams with more uniform bubbles were obtained


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