scholarly journals Modeling of chemical composition in the melt pool during laser welding of Aluminum / Magnesium alloys

2021 ◽  
Vol 321 ◽  
pp. 01008
Author(s):  
Sabrine Ben Halim ◽  
Wassim kriaa ◽  
Michel Autric
Keyword(s):  
Chemical Composition ◽  
Laser Welding ◽  
Magnesium Alloys ◽  
Chemical Elements ◽  
Welding Process ◽  
Intermetallic Phases ◽  
Transient Model ◽  
Melted Zone ◽  
Melt Pool ◽  
Aluminum Magnesium Alloys

Joining dissimilar metals is very difficult due to the formation of brittle intermetallic phases which may be detrimental to mechanical properties. The present work aims to investigate the transport phenomenon in the weld bead and to understand the materials mixing during laser welding process of dissimilar Aluminum-Magnesium alloys. A three-dimensional transient model based on fluid flow, heat and mass transfer has been developed to predict the formation of the weld and to study numerically and experimentally the diffusion of alloying elements in the melted zone. SEM analysis of chemical composition has been realized to map elements distribution in the melted zone. The results of simulation show the formation of a heterogeneous mixture in the melt pool. The elements distribution map and the presence of brittle intermetallic phases in the fusion zone were analysed. The formation of intermetallic compounds, comprising Al3Mg2 and Al12Mg17 phases were predicted by studying the chemical elements distribution in the weld pool. A good tendency between experimental and numerical results is noticed for the weld.

Multifactor mathematical model of criticality of welding process of products from aluminum- magnesium alloys

2020 ◽  
pp. 12-18
Author(s):  
F.A. Urazbahtin ◽  
A.YU. Urazbahtina
Keyword(s):  
Mathematical Model ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Welding Process ◽  
Welding Equipment ◽  
Equipment Operation ◽  
Aluminum Magnesium Alloys ◽  
Aluminum Magnesium Alloy ◽  
Welding Materials

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]

The Thermal Diffusivity of Mg-Al-Sr and Mg-Al-Ca-Sr Sand Casting Magnesium Alloys

2012 ◽  
Vol 326-328 ◽  
pp. 249-254
Author(s):  
Andrzej Kiełbus ◽  
Tomasz Rzychoń ◽  
Grzegorz Moskal
Keyword(s):  
Thermal Diffusivity ◽  
Chemical Composition ◽  
Magnesium Alloys ◽  
Volume Fraction ◽  
Intermetallic Phases ◽  
Sand Casting ◽  
Al Alloy ◽  
Temperature Dependent ◽  
Total Volume Fraction ◽  
Increasing Temperature

In the present study, the thermal diffusivity of four sand casting magnesium alloys: Mg-9Al-1Zn, Mg-6Al-2Sr, Mg-9Al-1.5Ca-0.3Sr and Mg-9Al-2.2Ca-0.8Sr were studied. Sand casting was performed at 730-780°C temperatures. Thermal diffusivity was measured by a LFA 427 Netzsch apparatus. The thermal diffusivity of the investigated alloys was chemical composition and temperature dependent and increased with increasing temperature. The thermal diffusivity of Mg-Al-Ca-Sr alloys was higher than that of Mg-Al alloy, because the total volume fraction of intermetallic phases in alloys containing calcium and strontium is larger than that in Mg-Al alloy. The formation of intermetallic phases caused the consumption of the solute element in the α-Mg matrix, and improved the thermal diffusivity of the Mg-Al-Ca-Sr magnesium alloy.

scholarly journals A Review on Melt-Pool Characteristics in Laser Welding of Metals

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Behzad Fotovvati ◽  
Steven F. Wayne ◽  
Gladius Lewis ◽  
Ebrahim Asadi
Keyword(s):  
Laser Welding ◽  
Process Parameters ◽  
Welding Process ◽  
Review Of The Literature ◽  
Influence Of Process Parameters ◽  
Melt Pool ◽  
Modeling Studies ◽  
Melt Pool Characteristics ◽  
Validation Of Results ◽  
Metal Additive

Laser welding of metals involves with formation of a melt-pool and subsequent rapid solidification, resulting in alteration of properties and the microstructure of the welded metal. Understanding and predicting relationships between laser welding process parameters, such as laser speed and welding power, and melt-pool characteristics have been the subjects of many studies in literature because this knowledge is critical to controlling and improving laser welding. Recent advances in metal additive manufacturing processes have renewed interest in the melt-pool studies because in many of these processes, part fabrication involves small moving melt-pools. The present work is a critical review of the literature on experimental and modeling studies on laser welding, with the focus being on the influence of process parameters on geometry, thermodynamics, fluid dynamics, microstructure, and porosity characteristics of the melt-pool. These data may inform future experimental laser welding studies and may be used for verification and validation of results obtained in future melt-pool modeling studies.

scholarly journals An Experimental Approach for the Direct Measurement of Temperatures in the Vicinity of the Keyhole Front Wall during Deep-Penetration Laser Welding

2020 ◽  
Vol 10 (11) ◽  
pp. 3951
Author(s):  
Ronald Pordzik ◽  
Peer Woizeschke
Keyword(s):  
Laser Welding ◽  
Boiling Point ◽  
High Speed ◽  
Pure Aluminum ◽  
Welding Process ◽  
Deep Penetration ◽  
Front Wall ◽  
Melt Pool ◽  
Direct Laser ◽  
Welding Processes

The formation of defects such as pores during deep-penetration laser welding processes is governed by the melt pool dynamics and the stability of the vapor capillary, also referred to as the keyhole. In order to gain an insight into the dynamics of the keyhole, the temperature in the transition region from the liquid to the gaseous phase, i.e., near the keyhole wall, is a physical value of fundamental importance. In this paper, a novel method is presented for directly measuring temperatures in the close vicinity of the keyhole front wall during deep-penetration laser welding. The weld samples consist of pure aluminum with a boiling point of 2743 K. The measurement is performed using high-speed pyrometry with a refractory tantalum probe capable of detecting temperatures that significantly exceed the boiling point of the sample material. Temperature curves are recorded from the beginning of the welding process until the moment the probe is finally destroyed through direct laser-tantalum interaction. With an effective spatial resolution up to 0.3 µm in the welding direction, a detailed investigation into the temperature ranging from the prerunning melt pool front to the keyhole center is possible, exhibiting temperatures of up to 3300 K in the vicinity of the keyhole front wall.

Friction Stir Welding of Tailored Blanks of Aluminum and Magnesium Alloys

2013 ◽  
Vol 549 ◽  
pp. 492-499 ◽  
Author(s):  
Jean Pierre Bergmann ◽  
René Schürer ◽  
Kevin Ritter
Keyword(s):  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Welding Process ◽  
Intermetallic Phases ◽  
Fusion Welding ◽  
Tool Geometry ◽  
Process Variables ◽  
Friction Stir ◽  
Tailored Blanks ◽  
Aluminum And Magnesium Alloys

The following paper describes a feasibility study of butt joining friction stir welding between aluminum alloy AA6016 and magnesium alloys AZ91 and AM50. Because of the variety of inimitable properties according to lightweight design and constructions, the interest in aluminum and magnesium alloys is increasing in many fields of industry. Due to the low solubility of aluminum in magnesium and inverse, these alloys tend to the formation of intermetallic phases during the joining process. This leads to an increasing micro hardness within the seam, which should be avoided. By the use of joining methods with low process temperatures, the formation of intermetallic phases is reduced. According to this circumstance, friction stir welding is an excellent alternative to fusion welding techniques used to join this alloys. The main welding process variables were exposed in the studies of similar butt joints of Al/Al and Mg/Mg. These were examined in connection to their transferability to the dissimilar joints and tailored blanks. Furthermore, the influence of different tool geometry on seam quality was investigated. The effect of process variables (mainly welding speed and revolution speed) were correlated to the results of tensile strength test. The welded samples were assayed in the presence of intermetallic phases.

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