Effect of GMAW-CMT Heat Input on Weld Bead Profile Geometry for Freeform Fabrication of Aluminium Parts

2013 ◽  
Vol 465-466 ◽  
pp. 1370-1374 ◽  
Author(s):  
Abdullah Wagiman ◽  
Mohd Saidin Bin Wahab ◽  
Zazuli Mohid ◽  
Azuddin Mamat
Keyword(s):  
Heat Input ◽  
Gas Metal Arc Welding ◽  
Great Influence ◽  
Dendritic Structure ◽  
Weld Bead ◽  
Cold Metal Transfer ◽  
Cross Sectional ◽  
Freeform Fabrication ◽  
Single Pass ◽  
Bead Profile

In developing a new method for weld based freeform fabrication, parameter affecting the geometry of single-pass need to be determined as it has great influence on dimensional accuracy and mechanical property of metallic part. In this paper, profile geometry and microstructure of single pass weld bead developed using Gas Metal Arc Welding Cold Metal Transfer (GMAW-CMT) was investigated. Observation on cross sectional weld bead indicates GMAW-CMT has capability to produce free spatter and crack defect weld bead. Profile geometry measurement shows weld bead develop at higher heat input has width size larger than the weld bead develop at lower heat input. Microstructure examination in the substrate reveals formation of columnar dendritic, cellular and planar structure while at buildup layer exhibit equiaxed dendritic structure

Weld bead graphical prediction of cold metal transfer weldment using ANFIS and MRA model on Matlab platform

SIMULATION ◽  
2018 ◽  
Vol 95 (8) ◽  
pp. 725-736 ◽  
Author(s):  
B Girinath ◽  
N Siva Shanmugam ◽  
K Sankaranarayanasamy
Keyword(s):  
Welding Process ◽  
Metal Transfer ◽  
Weld Bead ◽  
Graphical Form ◽  
Transport Sector ◽  
Cold Metal Transfer ◽  
Inference System ◽  
Input Parameters ◽  
Cold Metal ◽  
Bead Profile

A difficult task for the transport sector is to make its assemblies lighter and perform more efficiently. Use of aluminum and its alloys has increased extensively in this sector because of reduction in weight of the vehicles and resulting energy savings. High thermal conductivity and thermal expansion pose difficulty in welding of these alloys. Cold metal transfer (CMT), a low heat input welding process, is the best choice for welding of these alloys. However, controlling the welding input parameters is highly necessary to obtain defect-free and high strength welded joints. In the present study, an attempt is made to develop a Matlab software-based application by two approaches, such as multiple regression analysis (MRA) and adaptive neuro-fuzzy inference system (ANFIS), for predicting the complete weld bead shape (graphical representation) of AA5052 using the CMT welding process. The data inputs used for both approaches are welding current (A) and welding speed (mm/min), respectively. A graphical interface is built to help the user to choose welding input parameters and obtain directly a representation of the weld bead profile in graphical form. In addition, the output response shows the complete weld bead shape, which is defined by the X and Y coordinates of the various points in the weld bead profile. The results are validated with randomized tests against the weld bead shape predicted by Matlab. Comparatively, ANFIS is the more effective method for predicting the weld bead profile and shows better agreement with the experimental profile than MRA. Further, the reliability and stability of the ANFIS model were determined from the mean absolute error percentage, root mean square error values, and linear R2fit model, confirming that the ANFIS-based prediction is in better agreement with the experimental values than MRA.

PREDICTION OF LASER WELD BEAD PROFILE THROUGH AN INVERSE PROBLEM APPROACH

2018 ◽  
Author(s):  
Elisan dos Santos Magalhães ◽  
Luiz Eduardo dos Santos Paes ◽  
Milton Pereira ◽  
Sandro Metrevelle Marcondes de Lima e Silva
Keyword(s):  
Inverse Problem ◽  
Weld Bead ◽  
Laser Weld ◽  
Bead Profile

Suppurative Infections in Hospitalized Patients – An Ongoing MRSA Threat

2020 ◽  
Author(s):  
Sadaf Razzak
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Science ◽  
Great Influence ◽  
Antibiotic Sensitivity ◽  
Skin Lesions ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Inducible Clindamycin Resistance ◽  
Empiric Antibiotic ◽  
Medical Wards

Background: Penicillin resistance among Staphylococcus aureus commonly encountered in the hospital admitted patients. Detection of antibiotic sensitivity in hospital acquired methicillin resistant Staphylococcus aureus infections is important as it has great influence on empiric antibiotic prescription, successful control of infection, prevention of spread of disease and successful patient management. This study aimed to detect the frequency of HA-MRSA from pus samples in a hospital setup with assessment of their antibiotic susceptibility patterns. Method: A cross-sectional study was conducted in the Microbiology department of Basic Medical Science Institute, JPMC, Karachi from January 2015 until December 2015. Pus samples from surgical site wounds, skin lesions, abscesses from surgical and medical wards and ICUs were collected. According to the standards given by CLSI 2014, MRSA testing of the samples was done and susceptibility testing for antibiotics was performed. Inducible clindamycin resistance was detected by D-Test; E Test. determined MIC (minimum inhibitory concentration) for vancomycin. The data was analyzed by SPSS version 16. Result: Out of the 149 MRSA identified from the pus samples, 106 (71.14%) samples were HA-MRSA. The number of male patients was more than the female patients (67.66%). Out of the 106 HA-MRSA, 91(85.8%) were sensitive to TMP/SMX, 98(92.5%) to rifampicin, 12(11.6%) to gentamicin, 85(80.2%) to tetracycline, 11(10.4%) to erythromycin, 37(34.9%) to clindamycin, 20(18.9%) to ciprofloxacin, 106 (100%) to both vancomycin and linezolid. Conclusion: HA-MRSA showed sensitivity to TMP/SMX and vancomycin making them effective drugs to use in combination in superficial infections. The drug linezolid also showed 100% sensitivity.

Control of humping phenomenon and analyzing mechanical properties of Al–Si wire-arc additive manufacturing fabricated samples using cold metal transfer process

2021 ◽  
pp. 095440622199840
Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Large Scale ◽  
High Deposition Rate ◽  
Bead Geometry ◽  
Layer By Layer ◽  
Cold Metal Transfer ◽  
Geometrical Shapes ◽  
Wire Arc Additive Manufacturing

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.

scholarly journals Influence of post weld heat treatment on tensile properties of cold metal transfer (CMT) arc welded AA6061-T6 aluminium alloy joints

2019 ◽  
Vol 28 (1) ◽  
pp. 135-145 ◽  
Author(s):  
Addanki Ramaswamy ◽  
Sudersanan Malarvizhi ◽  
Visvalingam Balasubramanian
Keyword(s):  
Heat Treatment ◽  
Tensile Properties ◽  
Gas Metal Arc Welding ◽  
Weight Ratio ◽  
Welding Process ◽  
Metal Transfer ◽  
Post Weld Heat Treatment ◽  
Cold Metal Transfer ◽  
Cold Metal ◽  
Weld Heat

AbstractAluminium alloys of 6xxx series are widely used in the fabrication of light weight structures especially, where high strength to weight ratio and excellent weld-ability characteristics are desirable. Gas metal arc welding (GMAW) is the most predominantly used welding process in many industries due to the ease of automation. In this investigation, an attempt has been made to identify the best variant of GMAW process to overcome the problems like alloy segregation, precipitate dissolution and heat affected zone (HAZ) softening. Thin sheets of AA6061-T6 alloy were welded by cold metal transfer (CMT) and Pulsed CMT (PCMT). Among the two joints, the joint made by PCMT technique exhibited superior tensile properties due to the mechanical stirring action in the weld pool caused by forward and rearward movement of the wire along with the controllable diffusion rate at the interface caused by shorter solidification time. However, softening still exists in the welded joints. Further to increase the joint efficiency and to minimize HAZ softening, the joints were subjected to post weld heat treatment (PWHT). Approximately 10% improvement in the tensile properties had been observed in the PWHT joints due to the nucleation of strengthening precipitates in the weld metal and HAZ.

scholarly journals Effect of Filler Metal Type on Microstructure and Mechanical Properties of Fabricated NiAl Bronze Alloy Using Wire Arc Additive Manufacturing System

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 513
Author(s):  
Jae Won Kim ◽  
Jae-Deuk Kim ◽  
Jooyoung Cheon ◽  
Changwook Ji
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
Filler Metal ◽  
Gas Metal Arc Welding ◽  
Metal Wire ◽  
Cold Metal Transfer ◽  
Metal Type ◽  
Cold Metal ◽  
Wire Arc Additive Manufacturing

This study observed the effect of filler metal type on mechanical properties of NAB (NiAl-bronze) material fabricated using wire arc additive manufacturing (WAAM) technology. The selection of filler metal type is must consider the field condition, mechanical properties required by customers, and economics. This study analyzed the bead shape for representative two kind of filler metal types use to maintenance and fabricated a two-dimensional bulk NAB material. The cold metal transfer (CMT) mode of gas metal arc welding (GMAW) was used. For a comparison of mechanical properties, the study obtained three specimens per welding direction from the fabricated bulk NAB material. In the tensile test, the NAB material deposited using filler metal wire A showed higher tensile strength and lower elongation (approx. +71 MPa yield strength, +107.1 MPa ultimate tensile strength, −12.4% elongation) than that deposited with filler metal wire B. The reason is that, a mixture of tangled fine α platelets and dense lamellar eutectoid α + κIII structure with β´ phases was observed in the wall made with filler metal wire A. On the other hand, the wall made with filler metal wire B was dominated by coarse α phases and lamellar eutectoid α + κIII structure in between.

Sign in / Sign up

Export Citation Format

Share Document