Analysis of the Laser Droplet Formation Process

2005 ◽  
Vol 128 (1) ◽  
pp. 307-314 ◽  
Author(s):  
Tadej Kokalj ◽  
Jure Klemenčič ◽  
Peter Mužič ◽  
Igor Grabec ◽  
Edvard Govekar

In this paper, a novel laser droplet formation process (LDFP) from a metal wire is investigated. The process consists of the formation of a molten pendant droplet and its detachment, which are both unstable and influenced by numerous process parameters. The goal of the investigation is to specify the main process parameters and the values that provide for stable and repeatable process. Based on theoretical and experimental consideration of LDFP, a methodology for estimation of process control parameters is proposed. Estimation of the parameters is demonstrated on examples of deposited droplets of nickel and tin-alloy wires. Experimental results on tin-alloy wire indicate that the problem of splashes on the substrate is still present, while those on nickel reveal an acceptable formation of droplets.

2012 ◽  
Vol 522 ◽  
pp. 41-46
Author(s):  
Adayi Xieeryazidan ◽  
Muhetar Wumerhali ◽  
Gui Bing Pang

Electrochemical finishing with pulsed current (ECFP) is introduced in this paper. The main process parameters, such as electric parameter and inter-electrode gap, etc., were investigated. The results show that the ECFP is an effective finishing method for improving the machining quality as the result of the machining mechanism. The related experimental results show that the obtained surface quality and dimensional accuracy are improved significantly as the result of the application of the pulsed current. Moreover, machining quality is increased with shorter pulses.


2010 ◽  
Vol 7 (1) ◽  
pp. 42 ◽  
Author(s):  
Saurav Datta ◽  
Siba Sankar Mahapatra

 Submerged arc welding (SAW) is an important metal fabrication technology specially applied to join metals of large thickness in a single pass. In order to obtain an efficient joint, several process parameters of SAW need to be studied and precisely selected to improve weld quality. Many methodologies were proposed in the past research to address this issue. However, a good number of past work seeks to optimize SAWprocess parameters with a single response only. In practical situations, not only is the influence of process parameters and their interactive effects on output responses are to be critically examined but also an attempt is to be made to optimize more than one response, simultaneously. To this end, the present study considers four process control parameters viz. voltage (OCV), wire feed rate, traverse speed and electrode stick-out. The selected weld quality characteristics related to features of bead geometry are depth of penetration, reinforcement and bead width. In the present reporting, an integrated approach capable of solving the simultaneous optimization of multi-quality responses in SAW was suggested. In the proposed approach, the responses were transformed into their individual desirability values by selecting appropriate desirability function. Assuming equal importance for all responses, these individual desirability values were aggregated to calculate the overall desirability values. Quadratic Response Surface Methodology (RSM) was applied to establish a mathematical model representing overall desirability as a function involving linear, quadratic and interaction effect of process control parameters. This model was optimized finally within the experimental domain using PSO (Particle Swarm Optimization) algorithm. A confirmatory test showed a satisfactory result. A detailed methodology of RSM, desirability function (DF) and a PSO-based optimization approach was illustrated in the paper. 


2019 ◽  
Vol 25 (4) ◽  
pp. 407-412 ◽  
Author(s):  
Pragadish NAGARAJAN ◽  
Pradeep Kumar MURUGESAN ◽  
Elango NATARAJAN

Dry Electrical Discharge Machining (EDM) is considered as a green manufacturing process in which the liquid dielectric medium is replaced by a high velocity gas, which results improved process stability. A special tool design is adopted to find the optimum control parameters during machining of LM13 Aluminum alloy under dry EDM mode. The drilled and slotted cylindrical copper rod is used as a tool. Discharge current (I), voltage (V), pressure (P) and pulse on time (TON) are considered as varying input process parameters and duty factor and tool rotational speed are chosen at the fixed level. Taguchi L27 orthogonal array is used to design the experiment and the experiments are conducted accordingly. The experimental results are analyzed using Grey Relational Analysis to find the optimal combination of the process parameters. Also, ANOVA test is conducted to ensure the conformity of the simulation results. Pulse on time is found as the most significant parameter which is followed by voltage. Furthermore, the parameters with the highest relational grade (4 A, 200 μs, 60 V and 1.5 kPa) are used in experiment to validate the simulation results. The simulation and experimental results have a good agreement with less than 0.5 % error.


2013 ◽  
Vol 470 ◽  
pp. 577-580 ◽  
Author(s):  
Shuai Shuai Lu ◽  
Xiu Li Fu ◽  
Xiang Bo Ze

The research object is 40Cr shaft parts after quenched and tempered. Optimize the main process parameters working pressure, frequency and amplitude of ultrasonic finishing. It is obtained that the various parameters influence the surface roughness of the machining samples and the optimum technological parameters combination which is consistent with experimental results. Using the SPSS software to analyze the results, obtained the process parameters impact trend of the postprocessing roughness. Contrast groups of test data, the best result was reduced by 98.4% compared with the initial roughness , reached the Ra0.04μm.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4375
Author(s):  
David G. Andrade ◽  
Sree Sabari ◽  
Carlos Leitão ◽  
Dulce M. Rodrigues

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.


2016 ◽  
Vol 716 ◽  
pp. 114-120 ◽  
Author(s):  
Sebastian Mróz ◽  
Piotr Szota ◽  
Teresa Bajor ◽  
Andrzej Stefanik

The paper presents the results of physical modelling of the plastic deformation of the Mg/Al bimetallic specimens using the Gleeble 3800 simulator. The plastic deformation of Mg/Al bimetal specimens characterized by the diameter to thickness ratio equal to 1 was tested in compression tests. The aim of this work was determination of the range of parameters as temperature and strain rate that mainly influence on the plastic deformation of Mg/Al bars during metal forming processes. The tests were carried out for temperature range from 300 to 400°C for different strain rate values. The stock was round 22.5 mm-diameter with an Al layer share of 28% Mg/Al bars that had been produced using the explosive welding method. Based on the analysis of the obtained testing results it has been found that one of the main process parameters influencing the plastic deformation the bimetal components is the initial stock temperature and strain rate values.


2012 ◽  
Vol 588-589 ◽  
pp. 1156-1160
Author(s):  
Ge Ge Mei ◽  
Bin Jin ◽  
Wei Gong

Wire bonding is rapidly developmental technology of microelectronic packaging nearly half a century and become the main trend of semiconductor packaging field currently. This article introduces the main process parameters influencing on bonding quality, the methods to improve the bonding reliability, and prospects of developmental tendency of wire bonding.


2010 ◽  
Vol 43 ◽  
pp. 578-582 ◽  
Author(s):  
C.Y. Wang ◽  
Q. Dong ◽  
X.X. Shen

Warpage is a crucial factor to accuracy of sintering part in selective laser sintering (SLS) process. In this paper, The influence of process parameters on warpage when sintering polystyrene(PS) materials in SLS are investigated. The laser power, scanning speed, hatch spacing, layer thickness as well as temperature of powder are considered as the main process parameters. The results showed that warpage increases with the increase of hatch space. Contary to it, warpage decreases with the increase of laser power. Warpage decreases with the increase of layer thickness between 0.16~0.18mm and changes little with increase of the thickness. Warpage increases along with the increase of scanning speed but decreases when the speed is over about 2000mm/s. When the temperature changes between 82°C-86°C, warpage decreases little with the increase of temperature. But further increase of temperature leads to warpage decreasing sharply when the temperature changes between 86°C-90°C.


2012 ◽  
Vol 192 ◽  
pp. 180-184 ◽  
Author(s):  
Ai Xia He ◽  
Rong Chang Li

Mechanical expanding process for large diameter line pipe, a detailed analysis of factors affecting the quality of the final products of the mechanical expansion and proposed optimization using orthogonal array optimization method, as an indicator of dimensional accuracy and shape accuracy of the products, combination of a variety of specifications of mechanical expanding products, the main process parameters to be optimized. Analysis and discussion of results, revealing the degree of influence of various factors on the quality of the final product, and gives the optimum combination of the results. Experiments show that the combination of optimized process parameters, and more help to improve the accuracy of the size and shape of products.


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