Influence of the laser welding process on changes in the magnetic induction of the Religa Heart ROT pump

The study addresses the results concerning the laser welding technology of the titanium circulatory support blood pump Religa Heart ROT. Pulse laser welding parameters were determined and selected. The influence of the pulse welding parameters and other conditions of welding process on the magnetic induction distribution of the mechanical circulatory support blood pump was investigated.

Download Full-text

Temporary Mechanical Circulatory Support: A Review of the Options, Indications, and Outcomes

Clinical Medicine Insights Cardiology ◽

10.4137/cmc.s15718 ◽

2014 ◽

Vol 8s1 ◽

pp. CMC.S15718 ◽

Cited By ~ 10

Author(s):

Nisha A. Gilotra ◽

Gerin R. Stevens

Keyword(s):

Extracorporeal Membrane Oxygenation ◽

Mechanical Circulatory Support ◽

Clinical Applications ◽

Ventricular Assist Devices ◽

Blood Pump ◽

Circulatory Support ◽

Disease Entity ◽

Significant Morbidity ◽

Ventricular Assist ◽

Acute Setting

Cardiogenic shock remains a challenging disease entity and is associated with significant morbidity and mortality. Temporary mechanical circulatory support (MCS) can be implemented in an acute setting to stabilize acutely ill patients with cardiomyopathy in a variety of clinical situations. Currently, several options exist for temporary MCS. We review the indications, contraindications, clinical applications, and evidences for a variety of temporary circulatory support options, including the intra-aortic balloon pump (IABP), extracorporeal membrane oxygenation (ECMO), CentriMag blood pump, and percutaneous ventricular assist devices (pVADs), specifically the TandemHeart and Impella.

Download Full-text

Optimization for Laser Welding Fillet Joint Based on Response Surface Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.211-212.1110 ◽

2011 ◽

Vol 211-212 ◽

pp. 1110-1114

Author(s):

Xiao Yun Zhang ◽

Yan Song Zhang

Keyword(s):

Laser Welding ◽

Response Surface ◽

Weld Seam ◽

Welding Process ◽

Galvanized Steel ◽

Plant Production ◽

Welding Parameters ◽

Technical Instructions ◽

Fillet Joint ◽

Laser Welding Process

The wide use of galvanized steel in automobile manufacturing brings much challenge to the roof to body-side laser welding process. Fillet joint is an effective way to solve this problem such as pore in laser welding process. However, there is little research on this type of complicated joint process. Focused on this problem, take metallographic size of weld seam as the weld quality criteria, response surface methodology (RSM) is used to study the influence of laser welding parameters on weld seam quality. Finally, the optimum welding parameters are concluded to give technical instructions for the plant production.

Download Full-text

Laser Welding Process: A Research Project on Quality Assurance and Control

Journal of Ship Production ◽

10.5957/jsp.2004.20.3.188 ◽

2004 ◽

Vol 20 (03) ◽

pp. 188-192

Author(s):

Luciano Manzon

Keyword(s):

Quality Assurance ◽

Laser Welding ◽

Welding Process ◽

Point Of View ◽

Integrated System ◽

Control Line ◽

Research Project ◽

Main Research ◽

Welding Technology ◽

And Control

For the industrial adoption of laser welding technology, it is important that the yards achieve full control of the process and that they and the classification societies reach a level of confidence in the technology to permit a reduced level of quality controls after the welds have been performed. This would lead to a practicable and easier implementation of the technology in the industrial field. This is the approach that two EU yards, Odense Steel Shipyard and Fincantieri, had in mind while developing, with the partnership of important EU research institutes and classification societies, the EU-supported research project Shipbuilding Laser Welds: An Integrated System for Assurance and Control of Quality (SHILWACQ). The author, who was the coordinator of the project, explains, from the point of view of an end user shipyard, how this approach was implemented following two main research lines:the quality assurance line, focusing on the "defect avoidance" criterion and the "defect acceptance" (fitness for purpose) criterion;the quality control line, concentrating on the on-line process monitoring and automated not-destructive-test inspection systems. The CO2 laser welding technology for small/medium-thickness steel hull components is addressed. The article explains the activity development and the scientific results achieved by the two research lines, as well as how these results have been tested and validated in the industrial environment.

Download Full-text

Study on Quality Control of the Laser Welding Joint

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.442.276 ◽

2013 ◽

Vol 442 ◽

pp. 276-281

Author(s):

Qiang Wu ◽

Lan Ying Xu

Keyword(s):

Laser Welding ◽

Salt Water ◽

Harmful Effect ◽

Welding Process ◽

High Strength ◽

Galvanized Steel ◽

Welding Parameters ◽

Test Results ◽

Welding Joint ◽

Corrosion Rates

During laser welding process of high-strength galvanized steel, adopting guiding arc plate and the connecting arc plate can avoid harmful effect resulted in unstable melting width. The galvanized layer protecting joint is inevitably lost by having been burned, which affects stain resistance of welding joint. So salt water with the concentration of 3% is used in the corrosion test for the samples welded under different laser parameters, mass variation and metallographic microscopes are gained after joint being corroded. The test results indicate that the corrosion rates of the joint are different under different welding parameters during laser welding of high-strength galvanized steel; their average corrosion rates are coincident with that of base metal and laser welding technology hardly effect corrosion resistance of the joint.

Download Full-text

The Application of the Hole Drilling Method to Define the Residual Stress of Dissimilar Laser Welded Components

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.7-8.133 ◽

2007 ◽

Vol 7-8 ◽

pp. 133-138 ◽

Cited By ~ 5

Author(s):

E.M. Anawa ◽

Abdul Ghani Olabi

Keyword(s):

Residual Stress ◽

Residual Stresses ◽

Laser Welding ◽

Power Plants ◽

Welding Process ◽

Hole Drilling ◽

Welding Parameters ◽

Heating Process ◽

Hole Drilling Method ◽

Drilling Method

Dissimilar metal welds between Ferritic steel and Austenitic steel (F/A)are commonly used in power plants, food industry, pharmaceutical industry and many other applications. There are many issues/problems associated with the joining of dissimilar materials, depending on the materials being joined and the process selected. During the laser welding process, residual stresses are introduced by a rise in temperature during the melting or heating process followed by a very quick cooling of the weld and the surrounding material. In this study, CO2 continuous laser welding has been successfully applied for joining 316 stainless steel with AISI 1009 low carbon steel F/A. Design of Experiment techniques (DOE) has been used for some of the selected welding parameters (laser power, welding speed, and focus position) to model the dissimilar F/A joints in terms of its residual stresses. The Hole-Drilling Method technique was use for measuring the residual stress of dissimilar welded components. Taguchi approach for selected welding parameters was applied and the output response was the residual stresses. The results were analysed using analysis of variance (ANOVA) and signal-tonoise (S/N) ratios for the effective parameters combination.

Download Full-text

Underwater Laser Welding of Pure Ti: Oxidation and Hardening Behaviors

Metals ◽

10.3390/met11040610 ◽

2021 ◽

Vol 11 (4) ◽

pp. 610

Author(s):

Manlelan Luo ◽

Pengyu Wei ◽

Quanhong Li ◽

Renzhi Hu ◽

Anguo Huang ◽

...

Keyword(s):

Water Vapor ◽

Laser Welding ◽

Layer Structure ◽

Water Environment ◽

Welding Process ◽

Welding Parameters ◽

Economical Method ◽

Underwater Laser ◽

Cp Ti

The local dry underwater laser welding of cp-Ti, with air as an assisting gas, and in a simulated underwater facility was researched, aiming to find a viable and economical method for repairing titanium alloy underwater vehicles in situ in the future. Macro-morphology, microstructure, and microhardness of the cp-Ti laser welds, as a function of welding parameters, were experimentally characterized. The oxidation and hardening behaviors of the welds were also studied in detail. It was found that local dry underwater laser welding with air assisted blowing is feasible for obtaining a complete and glossy weld. Compared with a weld in atmosphere, the cross-section morphology of the weld was almost unaffected by the special underwater welding environment. The weld presented a three-layer structure. High temperature and high pressure water vapor and local blowing are the direct causes of weld oxidation, and porosity defects further aggravate the oxidation behavior. The oxygen-enriched areas were mostly concentrated in the top area of the weld center and near the fusion zone, because of the higher number of grain boundaries and phase boundaries. In addition, the partial oxidation caused by local blowing and water vapor atmosphere, and also the higher strength acicular martensite caused by the rapid cooling effect of water, will lead to weld hardening. However, adjusting the welding process parameters, such as increasing the welding speed, can effectively reduce the microhardness of the weld. Our findings can provide an understanding of the influence of water environment on underwater laser welding, and verify the feasibility of a more economical method for the in situ repair of large underwater facilities.

Download Full-text

Technology and Properties of Peripheral Laser-Welded Micro-Joints

Materials ◽

10.3390/ma14123213 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3213

Author(s):

Szymon Tofil ◽

Hubert Danielewski ◽

Grzegorz Witkowski ◽

Krystian Mulczyk ◽

Bogdan Antoszewski

Keyword(s):

Dendritic Structure ◽

Welding Process ◽

Structure Characteristic ◽

Welding Parameters ◽

Steel Pipes ◽

Beam Focusing ◽

Joint Properties ◽

Distribution Of Elements ◽

316L Steel ◽

Pulse Welding

This article presents the results of research on the technology and peripheral properties of laser-welded micro-couplings. The aim of this research was to determine the characteristics of properly made joints and to indicate the range of optimal parameters of the welding process. Thin-walled AISI 316L steel pipes with diameters of 1.5 and 2 mm used in medical equipment were tested. The micro-welding process was carried out on a SISMA LM-D210 Nd:YAG laser. The research methods used were macroscopic and microscopic analyses of the samples, and assessment of the distribution of elements in the weld, the distribution of microhardness and the tear strength of the joint. As a result of the tests, the following welding parameters are recommended: a pulse energy of 2.05 J, pulse duration of 4 ms and frequency of 2 Hz, beam focusing to a diameter of 0.4 mm and a rotation speed of 0.157 rad/s. In addition, the tests show good joint properties with a strength of more than 75% of the thinner pipe, uniform distribution of alloying elements and a complex dendritic structure characteristic of pulse welding.

Download Full-text

NUMERICAL STUDY OF THE TEMPERATURE FIELD FOR Fe3Al LASER WELDING

Materiali in tehnologije ◽

10.17222/mit2020.185 ◽

2021 ◽

Vol 55 (3) ◽

Author(s):

Josef Bradáč ◽

Jiří Hozman ◽

Jan Lamač

Keyword(s):

Temperature Field ◽

Laser Welding ◽

Numerical Scheme ◽

Numerical Study ◽

Welding Process ◽

Beam Power ◽

Welding Parameters ◽

Original Experiment ◽

Butt Weld ◽

Welding Processes

The main objective of this paper was focused on a numerical study related to a proper evaluation of the temperature field during the laser-welding process. The investigated material used for the experiments was Fe3Al, given its properties and promising application potential. The original experiment was based on a 3D model of a butt weld. However, to reduce the computational complexity, a planar variant of the heat-transfer equation with suitable choices of surface and volumetric heat sources, given by modified Gaussian pulses, is used to model the temperature distribution in the fixed cross cut during the laser welding. Subsequently, the numerical scheme based on the discontinuous Galerkin method was employed to evaluate the temperature field more properly and to identify the main characteristics of the molten zone. Finally, the numerical study was performed for various combinations of the welding parameters, such as laser-beam power and welding speed. The obtained results were in good agreement with the expected behavior, and thus illustrate the optimization potential of the proposed numerical scheme in the similar issues of a laser-welding processes.

Download Full-text

Single-Side Resistance Spot Welding Process for Joining Pipes and Sheets

International Journal of Automation Technology ◽

10.20965/ijat.2013.p0114 ◽

2013 ◽

Vol 7 (1) ◽

pp. 114-119 ◽

Cited By ~ 2

Author(s):

Hitomi Nishibata ◽

◽

Shota Kikuchi ◽

Manabu Fukumoto ◽

Masato Uchihara

Keyword(s):

Resistance Spot Welding ◽

Spot Welding ◽

Numerical Study ◽

Welding Process ◽

Welding Parameters ◽

Resistance Spot ◽

Welding Technology ◽

Single Side ◽

Side Resistance ◽

Nugget Growth

This paper describes a Single-Side resistance Spot Welding (SSSW) process which is expected to be a productive welding technology for the joining of stamped sheet panels to hollow parts for auto bodies. To obtain guidelines for making a sound weld with the SSSW process, the effects of welding parameters and the alignment of specimens on nugget growth are investigated experimentally. In addition, a numerical study is carried out to discuss the mechanism of nugget growth in the SSSW process.

Download Full-text