Emanuel B. F. Dos Santos

Emanuel B. F. Dos Santos
University of Waterloo | UWaterloo · Department of Mechanical and Mechatronics Engineering

Master of Applied Science

About

25
Publications
15,151
Reads
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187
Citations
Introduction
Emanuel Santos is currently working as a research associate at the Centre for Advanced Materials Joining (CAMJ), Department of Mechanical and Mechatronics Engineering of the University of Waterloo. Previously, Emanuel worked at the Welding Engineering team of Liburdi Automation Inc. His master thesis focused on high speed imaging of metal transfer and on understanding the influence of current pulse profile on metal transfer in pulsed gas metal arc welding (GMAW-P).
Additional affiliations
May 2015 - April 2017
University of Waterloo
Position
  • Master's Student
Description
  • My research activities were mostly relate to arc welding, physics of arc, and using high speed imaging for metal transfer characterization. The activities were developed at the Centre for Advanced Materials Joining (CAMJ) research group.
May 2015 - April 2017
University of Waterloo
Position
  • Research Assistant
January 2014 - March 2015
Federal University of Pará
Position
  • Research Assistant
Description
  • Worked on the development of empirical models to predict the final weld bead geometry generated by the novel Cold Wire Gas Metal Arc Welding (CW-GMAW) process.
Education
May 2015 - April 2017
University of Waterloo
Field of study
  • Mechanical and Materials Engineering
March 2009 - December 2014
Federal University of Pará
Field of study
  • Mechanical Engineering

Publications

Publications (25)
Article
Full-text available
One of the major concerns in welding is achieving an adequate weld bead with a geometry that is capable of resisting imposed stresses. Hence, predicting the geometrical features of a new welding process is of fundamental importance. Statistical methods are the most commonly used for predicting such geometries, and they provide particular confidence...
Conference Paper
Full-text available
For high productivity weld fabrication, gas metal arc welding (GMAW) is typically used since it offers a combination of high deposition rate and travel speed. Recent advances in power supply technologies have increased the deposition rates in hot-wire tungsten inert gas (HW-TIG) welding, such that it is possible to achieve parameters which may be c...
Article
Full-text available
The electrical current required for a transition from globular to spray droplet transfer during gas metal arc welding (GMAW) is determined by the specified wire feed speed in the case of constant-voltage power supplies. Generally, in narrow groove welding, spray transfer is avoided, be-cause this transfer mode can severely erode the groove sidewall...
Article
The thermal efficiency of arc welding influences the cooling rate, peak temperature, and microstructures of a weld, which affects the material properties of the welded joint. This work quantifies the uncertainty of thermal efficiency measurements on gas metal arc welds using low (2.5 kW) and high (9.5 kW) arc powers. In order to understand the effe...
Article
The demand to join newer and higher strength materials has motivated the development of controlled arc current waveforms in order to control deposition and heat input. Controlled waveforms in pulsed gas metal arc welding (P-GMAW) where the current is pulsed result in reduced nominal heat input, distortion, and residual stresses. A method to further...
Article
Full-text available
Gas metal arc welding (GMAW) with direct current electrode negative (DCEN) can offer some advantages over direct current electrode positive (DCEP) welding, such as a higher electrode melting rate and lower heat input imposed onto the workpiece. Despite these advantages, DCEN is not commonly used in field applications due to instabilities caused by...
Article
Full-text available
Narrow gap welding is a prevalent technique used to decrease the volume of molten metal and heat required to fill a joint. Consequently, deleterious effects such as distortion and residual stresses may be reduced. One of the fields where narrow groove welding is most employed is pipeline welding where misalignment, productivity and mechanical prope...
Article
Full-text available
The microstructure and mechanical properties of gas metal arc welded joints in similar and dissimilar material combinations of ASTM A572 Grade 50 and A656 Grade 80 plates are reported. The properties of the welded plates were measured in terms of hardness, tensile behavior, and Charpy V-notch impact toughness at -29°C. Furthermore, the strain distr...
Conference Paper
Full-text available
The use of dual phase (DP) by automakers aims to reduce the car weight and consequently the CO2 emissions by decreasing the fuel consumption. Nowadays, most of the welds are made using spot and/or laser welding, however many applications still demand arc welding processes to meet cost and time limitations. In order to further improve productivity o...
Data
This video shows the drag of metal vapor from the secondary droplet to lower temperatures arc regions leading to fume formation. For more information linked research and full text available at http://www.mdpi.com/2076-3417/7/5/503
Data
Comparison of arc plasma and metal transfer for different camera settings and filter selections. For more information linked research and full text available at http://www.mdpi.com/2076-3417/7/5/503
Article
Full-text available
In this article, the camera settings for high-speed imaging of the arc, metal transfer and weld pool in the gas metal arc welding are investigated. The results show that by only changing camera exposure times and the selection of narrow bandpass filters, images that reveal features of the arc, such as the iron vapor dominated region, metal transfer...
Thesis
Full-text available
The increase in the requirements of safety and reliability demanded from the normalization institutes by the issue of normalizing standards, led to the need of the development of materials of superior properties. Owing to the development of metallurgy, the development of materials with extremely high values of strength and toughness was made possib...
Article
This article evaluates the performance of the cold-wire gas metal arc welding (CW-GMAW) process for narrow gap girth welds. The CW-GMAW process is characterized by the introduction of continuously fed non-energized wire (cold-wire) into the electric arc/weld pool region. The cold-wire is melted by using the surplus heat available at the arc and mol...
Article
Full-text available
This work compares the welding residual stresses of the cold-wire gas metal arc welding and conventional gas metal arc welding processes. Two techniques were used to measure the residual stresses: x-ray diffraction and acoustic birefringence. The base metal used was carbon manganese steel plates of 9.5 mm thickness. The results showed that the intr...
Conference Paper
Full-text available
This work aims to characterize the heat affected zone (HAZ) in narrow groove welds fabricated using the cold-wire gas metal arc welding process (CW-GMAW). Two weld joints, having three and four passes respectively, were produced using two heat input rates and the same groove geometry. The welds were produced using a high strength low alloy (HSLA) A...
Article
The influence of current profile and pulse parameters on droplet formation and transfer was investigated. One profile has an exponential ramp up and down in the current pulse shape, while the second is nearly square shaped. High speed photography, synchronized with a high speed data acquisition system, was used to monitor the droplet formation and...
Data
This high speed video shows droplet formation and detachment for two different pulse profiles at different settings. More details can be found in the article at http://dx.doi.org/10.1080/13621718.2017.1288889
Data
This video shows the metal beam stream transfers. The only parameter changed between the videos is the current pulse frequency and that affects the metal beam stream transfer stability.
Article
Full-text available
The characteristics of a pulsed gas metal arc welding (GMAW-P) process that simultaneously achieves streaming transfer and low arc length are described. The process uses a nearly square shaped current profile. It was found that when high pulse frequency pulses are used with high peak and low background current, stream metal transfer is achieved at...
Conference Paper
Full-text available
Four pulsed current profiles were compared during gas metal arc welding, which were distinct in terms of the peak to background current ratio and ramp rate from peak to background current. The influence of pulse profile was investigated at four different wire feed speeds ranging from 150 to 300 in/min. Duty cycle and travel speed were varied such t...
Conference Paper
Full-text available
An instrumented indentation approach is proposed as a method to directly measure the local yield strength distribution in each zone of gas metal arc welds produced in X80 linepipe. The joints were produced with different microstructures and mechanical properties by applying shielding gases with varying Ar/CO2 ratios of 50 to 15%CO2 and the addition...
Article
Full-text available
The fatigue strength of weld joints manufactured using GMAW and cold wire GMAW (CW-GMAW) were evaluated under stress-controlled cyclic loading. The material used in this study was class ASTM 131 grade A steel, joined using ER70S wire filler metal. The addition of cold wire addition led to a decrease in the amount of intergranular ferrite and an inc...
Conference Paper
Most of the interaction between solid bodies is done through the mechanical contact at their surfaces. Once contact is done, Hertzian stress are developed which often have very high values due to smaller interaction region. This process is the main factor of failure in mechanical elements like gears and ball bearings. Contact stress can also be dev...

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Projects

Projects (2)
Project
The influence of pulse profile in pulsed gas metal arc welding on dynamic of metal transfer is being investigated. Four pulse profiles are being analyzed for four different wire feeding speed, for welding parameters, in which most of the metal transfer is happening in the one droplet per pulse (ODPP) regime. So far, the results have shown that for the different pulses the droplet detaches at distinct time during the pulse and that size and droplet velocity also changes accordingly.