scholarly journals A Feasibility Study Comparing Two Commercial TIG Welding Machines for Deep Penetration

2019 ◽  
Vol 269 ◽  
pp. 01004
Author(s):  
Richard French ◽  
Hector Merin-Reyes ◽  
Will Yeadon
Keyword(s):  
Weld Pool ◽  
Feasibility Study ◽  
Tig Welding ◽  
Deep Penetration ◽  
Bead Width ◽  
The University ◽  
Deep Penetration Welding ◽  
Lower Production ◽  
Welding Technique

Developing a deep penetration TIG welding technique to produce welds of equal quality to the industrial standard practise of laser-based welding techniques has the potential to lower production complexity and cost. Higher currents levels are required to increase penetration depth in conventional TIG welding but this results in excessive weld bead width amongst other detrimental effects. However, through K-TIG and A-TIG techniques these detrimental effects can be circumnavigated. Prior experimental work on weld pool dynamics in conventional TIG welding in higher current regions has been sparse as TIG welding enhanced through novel techniques provides the best quality welds. This paper is an early feasibility study for novel deep penetration welding techniques motivated by observations made during research done at The University of Sheffield where unexpected activity in the weld pool was identified during TIG welding with a VBC IE500DHC between 300A – 1000A. This current range is labelled the ‘Red Region’. Understanding the fluid dynamics of the molten metal in the weld pool at the ‘ Red Region' current level will help in the creation of novel techniques for deep penetration TIG welding. Addressing this, this paper compares the quality of welds produced between 100A and 200A on 316 Stainless Steel by two industrially leading welding machines; the Miller Dynasty 350 and the VBCie 500DHC.

Simulation Study of Keyhole Formation during Laser Deep Penetration Welding

2010 ◽  
Vol 44-47 ◽  
pp. 400-403
Author(s):  
Ren Ping Wang ◽  
Y.P. Lei
Keyword(s):  
Temperature Distribution ◽  
Weld Pool ◽  
Deep Penetration ◽  
Free Surfaces ◽  
Coupled Equations ◽  
Flow And Heat Transfer ◽  
Laser Deep Penetration Welding ◽  
Fluent Software ◽  
Deep Penetration Welding ◽  
Melting And Solidification

The elaborated model solves the coupled equations of a laminar fluid flow and heat transfer to predict the temperature distribution in the weld pool. The enthalpy-porosity technique was employed to account for the latent heat during melting and solidification. The coupled effects of buoyancy and Marangoni forces are considered in this model. The volume-of-fluid (VOF) method was employed to track free surfaces of weld pool. The molten temperature distribution, velocity field and molten shape were calculated using FLUENT software. The results clearly demonstrate Marangoni flow significantly alters the characteristics of the thawing and solidifying process, and makes the molten wider and shallower.

Microstructures and Properties of Fiber Laser Welded ACM522 Magnesium Alloy Joint

2009 ◽  
Vol 610-613 ◽  
pp. 911-914 ◽  
Author(s):  
Jun Liu ◽  
Jun Hui Dong ◽  
K. Shinozaki
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Fiber Laser ◽  
Laser Power ◽  
Weld Bead ◽  
Deep Penetration ◽  
Fiber Laser Welding ◽  
Bead Width ◽  
Welding Joints ◽  
Deep Penetration Welding

The microstructure, mechanical properties, hardness, rules and mechanism of various parameters on formation of weld bead of Mg alloy ACM522 using a fiber laser welding were investigated. The results showed that sound welds without major defects could be produced and the mechanical properties of welding joints were good. With the increase of laser power, the penetration depth and bead width of the weld bead all increased. The mechanism of welding transformed from the conduction welding mode to the deep penetration welding mode and the weld beads aspect ratio became higher with the increase of heat input. The microstructure of weld metal was significantly finer and the hardness of weld metal was higher than that of the base metal.

scholarly journals Pulsed Nd: YAG Laser Parameters Effect on Welding Uncoated Advance High Strength Steel (AHSS) for Automotive

2021 ◽  
Vol 84 (1) ◽  
pp. 91-100
Author(s):  
Muhammad Naqiuddin Mat Salleh ◽  
Mahadzir Ishak ◽  
Kazuhiko Yamasaki ◽  
Moinuddin Mohammed Quazi ◽  
Aiman Mohd Halil
Keyword(s):  
Penetration Depth ◽  
Weld Pool ◽  
Welding Speed ◽  
High Strength Steel ◽  
Focal Length ◽  
High Strength ◽  
Boron Steel ◽  
Deep Penetration ◽  
Bead Width ◽  
Yag Laser

Pulse wave (PW) welding technique has become more adequate process to produce a deep penetration welding with smaller fusion zone and heat affected zone for automotive steel joint. A 1.6 mm thickness of N22CB boron steel from advance high strength steel (AHSS) type was welded by using PW mode from a low power Nd: YAG laser. The process parameters studied in this paper are pulsed energy, Ep, focal length, F, and welding speed, S. Bead-on-plate (BOP) welding was used in this experiment. The effect of parameters on the weld pool geometry was studied. Higher pulsed energy gives high weld penetration and higher weld width, contributing to the bigger weld pool size. Positive defocus position of focal length produces weld geometry with high penetration depth and smaller bead width compared to negative defocus position. Lower welding speed could produce deep penetration depth as the high heat input produced.

Epistemic and relational conflicts in sharing identical vs. complementary information during cooperative learning

2002 ◽  
Vol 61 (3) ◽  
pp. 139-151 ◽  
Author(s):  
Céline Darnon ◽  
Céline Buchs ◽  
Fabrizio Butera
Keyword(s):  
Cooperative Learning ◽  
Social Comparison ◽  
Positive Relationship ◽  
Learning Task ◽  
Control Group ◽  
Complementary Information ◽  
Relational Conflict ◽  
The Social ◽  
The University

When interacting on a learning task, which is typical of several academic situations, individuals may experience two different motives: Understanding the problem, or showing their competences. When a conflict (confrontation of divergent propositions) emerges from this interaction, it can be solved either in an epistemic way (focused on the task) or in a relational way (focused on the social comparison of competences). The latter is believed to be detrimental for learning. Moreover, research on cooperative learning shows that when they share identical information, partners are led to compare to each other, and are less encouraged to cooperate than when they share complementary information. An epistemic vs. relational conflict vs. no conflict was provoked in dyads composed by a participant and a confederate, working either on identical or on complementary information (N = 122). Results showed that, if relational and epistemic conflicts both entailed more perceived interactions and divergence than the control group, only relational conflict entailed more perceived comparison activities and a less positive relationship than the control group. Epistemic conflict resulted in a more positive perceived relationship than the control group. As far as performance is concerned, relational conflict led to a worse learning than epistemic conflict, and - after a delay - than the control group. An interaction between the two variables on delayed performance showed that epistemic and relational conflicts were different only when working with complementary information. This study shows the importance of the quality of relationship when sharing information during cooperative learning, a crucial factor to be taken into account when planning educational settings at the university.

Evaluation of the Academic Setting in Spain 1This study was financed by the University of Oviedo.

1995 ◽  
Vol 11 (2) ◽  
pp. 133-137 ◽  
Author(s):  
Juan Fernández ◽  
Miguel A. Mateo ◽  
José Muñiz
Keyword(s):  
Higher Education ◽  
Decision Making ◽  
Social Climate ◽  
Three Dimensions ◽  
Academic Setting ◽  
Teaching And Research ◽  
Evaluation Questionnaire ◽  
University Teachers ◽  
The University

The conditions are investigated in which Spanish university teachers carry out their teaching and research functions. 655 teachers from the University of Oviedo took part in this study by completing the Academic Setting Evaluation Questionnaire (ASEQ). Of the three dimensions assessed in the ASEQ, Satisfaction received the lowest ratings, Social Climate was rated higher, and Relations with students was rated the highest. These results are similar to those found in two studies carried out in the academic years 1986/87 and 1989/90. Their relevance for higher education is twofold because these data can be used as a complement of those obtained by means of students' opinions, and the crossing of both types of data can facilitate decision making in order to improve the quality of the work (teaching and research) of the university institutions.

Development of the University of Toronto Skull Base Inventory (UT-SBI) Quality-of-Life Questionnaire

Skull Base ◽  
2009 ◽  
Vol 19 (03) ◽  
Author(s):  
John de Almeida ◽  
Allan Vescan ◽  
Jolie Ringash ◽  
Patrick Gullane ◽  
Fred Gentili ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Skull Base ◽  
Life Questionnaire ◽  
Quality Of Life Questionnaire ◽  
University Of Toronto ◽  
The University

Development of ultra deep penetration welding with 10 kW fiber laser

2008 ◽  
Author(s):  
Xudong Zhang ◽  
Eiji Ashida ◽  
Seiji Katayama ◽  
Masami Mizutani
Keyword(s):  
Fiber Laser ◽  
Deep Penetration ◽  
Deep Penetration Welding

A Futures Study on the Quality Of Life from the Point Of View of Iranian Youth

2017 ◽  
Vol 14 (2) ◽  
pp. 1
Author(s):  
Sina Saeedy ◽  
Mojtaba Amiri ◽  
Mohammad Mahdi Zolfagharzadeh ◽  
Mohammad Rahim Eyvazi
Keyword(s):  
Quality Of Life ◽  
Life Satisfaction ◽  
Mixed Model ◽  
Satisfaction With Life ◽  
Point Of View ◽  
Human Society ◽  
Futures Studies ◽  
The Social ◽  
The University

Quality of life and satisfaction with life as tightly interconnected concepts have become of much importance in the urbanism era. No doubt, it is one of the most important goals of every human society to enhance a citizen’s quality of life and to increase their satisfaction with life. However, there are many signs which demonstrate the low level of life satisfaction of Iranian citizens especially among the youth. Thus, considering the temporal concept of life satisfaction, this research aims to make a futures study in this field. Therefore, using a mixed model and employing research methods from futures studies, life satisfaction among the students of the University of Tehran were measured and their views on this subject investigated. Both quantitative and qualitative data were analysed together in order to test the hypotheses and to address the research questions on the youth discontentment with quality of life. Findings showed that the level of life satisfaction among students is relatively low and their image of the future is not positive and not optimistic. These views were elicited and discussed in the social, economic, political, environmental and technological perspectives. Keywords:  futures studies, quality of life, satisfaction with life, youth

Building research capacity and capabilities in Fiji: are we there yet?

2020 ◽  
Vol 21 (5) ◽  
pp. 265-271
Author(s):  
Jyotishna Mudaliar ◽  
Bridget Kool ◽  
Janice Natasha ◽  
Judith McCool
Keyword(s):  
Low Income ◽  
Research Capacity ◽  
Research Knowledge ◽  
Research Skills ◽  
Research Findings ◽  
Access And Quality ◽  
The University ◽  
Local Investigator ◽  
Research Capacity Development

Introduction: A barrier to local investigator-led research in low income settings, is the limited availability of personnel with appropriate research skills or qualifications to conduct the type of research required for evidence-informed policy making to improve access and quality of health care. In response to this, Fiji National University’s College of Medicine, Nursing and Health Sciences in Fiji, collaborated with academics based at the University of Auckland, New Zealand to deliver a series of research capacity development workshops in Fiji. Methods: Participants who attended any of the nine workshops (n=123) were contacted via email to take part in a brief survey regarding their perceptions of the effectiveness of the research capacity building workshops. Of the possible 123 participants, 80% (n=76) completed the questionnaire.  Results: Findings demonstrate that the majority of participants reported that they had gained research skills from the workshops (75%) including proposal development skills (68%) and knowledge of appropriate research methods (59%). Furthermore, 70% agreed that the workshops built their research confidence.  Since attending a workshop, 18% of respondents had successfully applied and received funding for research grants and/or fellowships.  Barriers to conduct research included workload (75%), lack of research knowledge, experience or skills (51%), and lack of institutional support (41%). Suggestions for future workshops included: more focus on data analysis, regular courses rather than ‘one offs’, and preparation of research findings (e.g. publications). Conclusion: Our findings indicate that research workshops of this nature may increase individual research capabilities but sustained, locally led initiatives, backed by institutional and supplementary technical support are essential.

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