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Welding, Joining and Coating of Metallic Materials
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Welding, Joining and Coating of Metallic Materials

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Materials Physics".

Deadline for manuscript submissions: closed (31 December 2019) | Viewed by 84350

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Prof. Dr. Michael Zinigrad

E-Mail Website
Guest Editor
Department of Chemical Engineering, Biotechnology and Materials, Materials Research Center, Ariel University, Ariel 40700, Israel
Interests: materials science and materials engineering, mathematical modeling and simulation; founded the research laboratory for advanced materials investigations; theoretical and experimental investigations on high-temperature processes; development of new materials based on mathematical modeling of physicochemical and technological processes; plasma electrolytic oxidation (PEO) coatings on aluminum and magnesium alloys created in aqueous solution and molten salt electrolytes; solid oxide fuel cell investigation; metal alloys strengthening by nanoparticles; ink-jet printed thin layers
Special Issues, Collections and Topics in MDPI journals
Prof. Dr. Konstantin Borodianskiy

E-Mail Website1 Website2
Guest Editor
Department of Chemical Engineering, Ariel University, Ariel 40700, Israel
Interests: functional and bioactive coatings; microstructural engineering; materials for solid oxide fuel cells; metallurgy; Al alloys; metallic properties
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Since the beginning of the 19th century, metallic materials have been highly attracted in the scientific and industrial world. Welding, joining and coating are among the most important methods in metallic processing. The majority of research works deal with obtaining the required chemical and phase compositions, microstructures, and mechanical, physical and technological properties.

Furthermore, in last two decades, the development of a combined technology where traditional processes join up with advanced methods of nanoscience is in the focus of the scientific community. More and more research is dedicated to the interaction between the traditional metals technology and nanotechnology approaches achieving materials with improved mechanical, physical, chemical and technological properties.

The scope of the forthcoming Special Issue will focus on recent innovative and pioneering works in the field of metallic materials processes of welding, joining and coating. Topics include, but are not limited to:

  • Ferrous and non-ferrous alloys welding processes
  • Advanced methods of metallic materials joining
  • Metals solidification processes
  • Alloying and modification of metallic materials
  • Metals advanced coatings
  • Modeling and simulation

We invite our colleagues to submit a manuscript, which can be in the form of a full paper, communication or a review to this Special Issue.

Prof. Dr. Michael Zinigrad
Dr. Konstantin Borodianskiy
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • welding
  • solidification
  • coating
  • metals
  • materials properties
  • build-up

Published Papers (22 papers)

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Editorial

Jump to: Research

3 pages, 151 KiB  
Editorial
Welding, Joining, and Coating of Metallic Materials
by Michael Zinigrad and Konstantin Borodianskiy
Materials 2020, 13(11), 2640; https://doi.org/10.3390/ma13112640 - 10 Jun 2020
Cited by 2 | Viewed by 2122
Abstract
Welding, joining, and coating of metallic materials are among the most applicable fabrication processes in modern metallurgy. Welding or joining is the manufacture of a metal one-body workpiece from several pieces. Coating is the process of production of metallic substrate with required properties [...] Read more.
Welding, joining, and coating of metallic materials are among the most applicable fabrication processes in modern metallurgy. Welding or joining is the manufacture of a metal one-body workpiece from several pieces. Coating is the process of production of metallic substrate with required properties of the surface. A long list of specific techniques is studied during schooling and applied in industry; several include resistant spot, laser or friction welding, micro arc oxidation (MAO), chemical vapor deposition (CVD), and physical vapor deposition (PVD), among others. This Special Issue presents 21 recent developments in the field of welding, joining, and coating of various metallic materials namely, Ti and Mg alloys, different types of steel, intermetallics, and shape memory alloys. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)

Research

Jump to: Editorial

11 pages, 2709 KiB  
Article
Study of the Effect of Current Pulse Frequency on Ti-6Al-4V Alloy Coating Formation by Micro Arc Oxidation
by Alexander Sobolev, Alexey Kossenko and Konstantin Borodianskiy
Materials 2019, 12(23), 3983; https://doi.org/10.3390/ma12233983 - 01 Dec 2019
Cited by 40 | Viewed by 2814
Abstract
The micro arc oxidation (MAO) process has been applied to produce ceramic oxide coating on Ti-6Al-4V alloy. The MAO process was carried out at the symmetric bipolar square pulse in electrolyte containing Na2CO3 and Na2SiO3. The [...] Read more.
The micro arc oxidation (MAO) process has been applied to produce ceramic oxide coating on Ti-6Al-4V alloy. The MAO process was carried out at the symmetric bipolar square pulse in electrolyte containing Na2CO3 and Na2SiO3. The effect of current frequency on the surface morphology, the chemical and the phase compositions as well as the corrosion resistance was examined. Morphology and cross-sectional investigation by electron microscopy evaluated more compacted and less porous coating produced by high current frequency (1000 Hz). This alloy also exhibited a high corrosion resistance in comparison with the untreated alloy. Additionally, the alloy subjected to MAO treatment by a current frequency of 1000 Hz showed a higher corrosion resistance in comparison with alloys obtained by lower current frequencies. This behavior was attributed to more compacted and less porous morphology of the coating. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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9 pages, 2674 KiB  
Article
Stress Concentration Induced by the Crystal Orientation in the Transient-Liquid-Phase Bonded Joint of Single-Crystalline Ni3Al
by Hongbo Qin, Tianfeng Kuang, Qi Li, Xiong Yue, Haitao Gao, Fengmei Liu and Yaoyong Yi
Materials 2019, 12(17), 2765; https://doi.org/10.3390/ma12172765 - 28 Aug 2019
Cited by 6 | Viewed by 2825
Abstract
Single-crystalline Ni3Al-based superalloys have been widely used in aviation, aerospace, and military fields because of their excellent mechanical properties, especially at extremely high temperatures. Usually, single-crystalline Ni3Al-based superalloys are welded together by a Ni3Al-based polycrystalline alloy via [...] Read more.
Single-crystalline Ni3Al-based superalloys have been widely used in aviation, aerospace, and military fields because of their excellent mechanical properties, especially at extremely high temperatures. Usually, single-crystalline Ni3Al-based superalloys are welded together by a Ni3Al-based polycrystalline alloy via transient liquid phase (TLP) bonding. In this study, the elastic constants of single-crystalline Ni3Al were calculated via density functional theory (DFT) and the elastic modulus, shear modulus, and Poisson’s ratio of the polycrystalline Ni3Al were evaluated by the Voigt–Reuss approximation method. The results are in good agreement with previously reported experimental values. Based on the calculated mechanical properties of single-crystalline and polycrystalline Ni3Al, three-dimensional finite element analysis (FEA) was used to characterize the mechanical behavior of the TLP bonded joint of single-crystalline Ni3Al. The simulation results reveal obvious stress concentration in the joint because of the different states of crystal orientation between single crystals and polycrystals, which may induce failure in the polycrystalline Ni3Al and weaken the mechanical strength of the TLP bonded joint. Furthermore, results also show that the decrease in the elastic modulus of the intermediate layer (i.e., polycrystalline Ni3Al) can relieve the stress concentration and improve the mechanical strength in the TLP bonded joint. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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14 pages, 7346 KiB  
Article
A Primary Study of Variable Polarity Plasma Arc Welding Using a Pulsed Plasma Gas
by Zhenyang Lu, Wang Zhang, Fan Jiang, Shujun Chen and Zhaoyang Yan
Materials 2019, 12(10), 1666; https://doi.org/10.3390/ma12101666 - 22 May 2019
Cited by 4 | Viewed by 3236
Abstract
A process variant of variable polarity plasma arc welding (VPPAW), that is, the pulsed plasma gas VPPAW process, was developed. The pulsed plasma gas was transmitted into the variable polarity plasma arc through a high-frequency solenoid valve to modify the output of the [...] Read more.
A process variant of variable polarity plasma arc welding (VPPAW), that is, the pulsed plasma gas VPPAW process, was developed. The pulsed plasma gas was transmitted into the variable polarity plasma arc through a high-frequency solenoid valve to modify the output of the plasma arc. The collection of arc electrical characteristics, arc shapes, and weld formation from VPPAW, double-pulsed VPPAW (DP-VPPAW), and pulsed plasma gas VPPAW (PPG-VPPAW) was carried out to examine if the pulsed plasma gas was able to play a positive role in improving the stability and quality of the VPPAW process. The arc voltage shows that the pulsed plasma gas had a greater influence on the electrode positive polarity voltage. The lower the plasma gas frequency was, the lower the arc voltage fluctuation frequency was and the greater the arc voltage fluctuation amplitude was. From the arc image, it could be observed that the arc core length had a short decrease during the general rising trend after plasma gas was turned on. The arc core width only had a slight change due to the restriction of the torch orifice. Compared with pulsed current wave, the pulsed plasma gas could better enhance the fluidity of the molten pool to reduce porosity during aluminum keyhole welding. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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12 pages, 8750 KiB  
Article
Effect of Heat Treatment on the Microstructure and Properties of a Ti3Al Linear Friction Welding Joint
by Xiaohong Li, Jianchao He, Tiancang Zhang, Jun Tao, Ju Li and Yanhua Zhang
Materials 2019, 12(7), 1159; https://doi.org/10.3390/ma12071159 - 10 Apr 2019
Cited by 8 | Viewed by 2395
Abstract
Heat treatment at different temperatures was carried out on a Ti3Al linear friction welding joint. The characteristics and evolution of the microstructure in the weld zone (WZ) and the thermo-mechanically affected zone (TMAZ) of the Ti3Al LFW joint were [...] Read more.
Heat treatment at different temperatures was carried out on a Ti3Al linear friction welding joint. The characteristics and evolution of the microstructure in the weld zone (WZ) and the thermo-mechanically affected zone (TMAZ) of the Ti3Al LFW joint were analyzed. Combined with the heat treatment after welding, the effect of the heat treatment temperature on the joint was discussed. The test results indicated that the linear friction welding (LFW) process can accomplish a reliable connection between Ti3Al alloys and the joint can avoid defects such as microcracks and voids. The weld zone of the as-welded Ti3Al alloy joint was mainly composed of metastable β phase, while the TMAZ was mainly composed of deformed α2 phase and metastable β phase. After being heat treated at different temperatures, the WZ of the Ti3Al LFW joint exhibited a significantly different microstructure. After heat treatment at 700 °C, dot-like structures precipitated and the joint microhardness increased significantly. Subsequently, the joint microhardness decreases with the increase in temperature. Under heat treatment at temperatures above 850 °C, the formed structure was acicular α2 phase and the joint microhardness after heat treatment was lower than that of the as-welded joint. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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17 pages, 15149 KiB  
Article
Effect of Arc Pressure on the Digging Process in Variable Polarity Plasma Arc Welding of A5052P Aluminum Alloy
by Bin Xu, Shinichi Tashiro, Fan Jiang, Shujun Chen and Manabu Tanaka
Materials 2019, 12(7), 1071; https://doi.org/10.3390/ma12071071 - 01 Apr 2019
Cited by 16 | Viewed by 3130
Abstract
The keyhole digging process associated with variable polarity plasma arc (VPPA) welding remains unclear, resulting in poor control of welding stability. The VPPA pressure directly determines the dynamics of the keyhole and weld pool in the digging process. Here, through a high speed [...] Read more.
The keyhole digging process associated with variable polarity plasma arc (VPPA) welding remains unclear, resulting in poor control of welding stability. The VPPA pressure directly determines the dynamics of the keyhole and weld pool in the digging process. Here, through a high speed camera, high frequency pulsed diode laser light source and X-ray transmission imaging system, we reveal the potential physical phenomenon of a keyhole weld pool. The keyhole depth changes periodically corresponding to the polarity conversion period if the current is same in the electrode negative (EN) phase and electrode positive (EP) phase. There exist three distinct regimes of keyhole and weld pool behavior in the whole digging process, due to the arc pressure attenuation and energy accumulation effect. The pressure in the EP phase is smaller than that of the EN phase, causing the fluctuation of the weld pool free surface. Based on the influence mechanism of energy and momentum transaction, the arc pressure output is balanced by separately adjusting the current in each polarity. Finally, the keyhole fluctuation during the digging process is successfully reduced and welding stability is well controlled. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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14 pages, 4610 KiB  
Article
Effect of Plasma Nitriding Pretreatment on the Mechanical Properties of AlCrSiN-Coated Tool Steels
by Yin-Yu Chang and Siddhant Amrutwar
Materials 2019, 12(5), 795; https://doi.org/10.3390/ma12050795 - 07 Mar 2019
Cited by 28 | Viewed by 3957
Abstract
Surface modification of steel has been reported to improve hardness and other mechanical properties, such as increase in resistance, for reducing plastic deformation, fatigue, and wear. Duplex surface treatment, such as a combination of plasma nitriding and physical vapor deposition, achieves superior mechanical [...] Read more.
Surface modification of steel has been reported to improve hardness and other mechanical properties, such as increase in resistance, for reducing plastic deformation, fatigue, and wear. Duplex surface treatment, such as a combination of plasma nitriding and physical vapor deposition, achieves superior mechanical properties and resistance to wear. In this study, the plasma nitriding process was conducted prior to the deposition of hard coatings on the SKH9 substrate. This process was done by a proper mixture of nitrogen/hydrogen gas at suitable duty cycle, pressure, and voltage with proper temperature. Later on, the deposition of gradient AlCrSiN coatings synthesized by a cathodic-arc deposition process was performed. During the deposition of AlCrSiN, CrN, AlCrN/CrN, and AlCrSiN/AlCrN were deposited as gradient interlayers to improve adhesion between the coatings and nitrided steels. A repetitive impact test (200k–400k times) was performed at room temperature and at high temperature (~500 °C) to assess impact resistance. The results showed that the tribological impact resistance for the synthesized AlCrSiN increased because of a progressive hardness support. The combination of plasma nitriding and AlCrSiN hard coatings is capable of increasing the life of molding dies and metal forging dies in mass production. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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14 pages, 7005 KiB  
Article
Transient Liquid Phase Bonding of Ti-6Al-4V and Mg-AZ31 Alloys Using Zn Coatings
by Abdulaziz AlHazaa, Ibrahim Alhoweml, Muhammad Ali Shar, Mahmoud Hezam, Hany Sayed Abdo and Hamad AlBrithen
Materials 2019, 12(5), 769; https://doi.org/10.3390/ma12050769 - 06 Mar 2019
Cited by 16 | Viewed by 3310
Abstract
Ti-6Al-4V and Mg-AZ31 were bonded together using the Transient Liquid Phase Bonding Process (TLP) after coating both surfaces with zinc. The zinc coatings were applied using the screen printing process of zinc paste. Successful bonds were obtained in a vacuum furnace at 500 [...] Read more.
Ti-6Al-4V and Mg-AZ31 were bonded together using the Transient Liquid Phase Bonding Process (TLP) after coating both surfaces with zinc. The zinc coatings were applied using the screen printing process of zinc paste. Successful bonds were obtained in a vacuum furnace at 500 °C and under a uniaxial pressure of 1 MPa using high frequency induction heat sintering furnace (HFIHS). Various bonding times were selected and all gave solid joints. The bonds were successfully achieved at 5, 10, 15, 20, 25, and 30 min. The energy dispersive spectroscopy (EDS) line scan confirmed the diffusion of Zn in both sides but with more diffusion in the Mg side. Diffusion of Mg into the joint region was detected with significant amounts at bonds made for 20 min and above, which indicate that the isothermal solidification was achieved. In addition, Ti and Al from the base alloys were diffused into the joint region. Based on microstructural analysis, the joint mechanism was attributed to the formation of solidified mixture of Mg and Zn at the joint region with a presence of diffused Ti and Al. This conclusion was also supported by structural analysis of the fractured surfaces as well as the analysis across the joint region. The fractured surfaces were analyzed and it was concluded that the fractures occurred within the joint region where ductile fractures were observed. The strength of the joint was evaluated by shear test and found that the maximum shear strength achieved was 30.5 MPa for the bond made at 20 min. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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Graphical abstract

16 pages, 6794 KiB  
Article
Deposition of Stainless Steel Thin Films: An Electron Beam Physical Vapour Deposition Approach
by Naser Ali, Joao A. Teixeira, Abdulmajid Addali, Maryam Saeed, Feras Al-Zubi, Ahmad Sedaghat and Husain Bahzad
Materials 2019, 12(4), 571; https://doi.org/10.3390/ma12040571 - 14 Feb 2019
Cited by 32 | Viewed by 6060
Abstract
This study demonstrates an electron beam physical vapour deposition approach as an alternative stainless steel thin films fabrication method with controlled layer thickness and uniform particles distribution capability. The films were fabricated at a range of starting electron beam power percentages of 3–10%, [...] Read more.
This study demonstrates an electron beam physical vapour deposition approach as an alternative stainless steel thin films fabrication method with controlled layer thickness and uniform particles distribution capability. The films were fabricated at a range of starting electron beam power percentages of 3–10%, and thickness of 50–150 nm. Surface topography and wettability analysis of the samples were investigated to observe the changes in surface microstructure and the contact angle behaviour of 20 °C to 60 °C deionised waters, of pH 4, pH 7, and pH 9, with the as-prepared surfaces. The results indicated that films fabricated at low controlled deposition rates provided uniform particles distribution and had the closest elemental percentages to stainless steel 316L and that increasing the deposition thickness caused the surface roughness to reduce by 38%. Surface wettability behaviour, in general, showed that the surface hydrophobic nature tends to weaken with the increase in temperature of the three examined fluids. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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12 pages, 11565 KiB  
Article
Application of Cold Wire Gas Metal Arc Welding for Narrow Gap Welding (NGW) of High Strength Low Alloy Steel
by Rafael A. Ribeiro, Paulo D. C. Assunção, Emanuel B. F. Dos Santos, Ademir A. C. Filho, Eduardo M. Braga and Adrian P. Gerlich
Materials 2019, 12(3), 335; https://doi.org/10.3390/ma12030335 - 22 Jan 2019
Cited by 17 | Viewed by 4489
Abstract
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 [...] Read more.
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 properties are critical to a successful final assemblage of pipes. This work reports the feasibility of joining pipe sections with 4 mm-wide narrow gaps machined from API X80 linepipe using cold wire gas metal arc welding. Joints were manufactured using the standard gas metal arc welding and the cold wire gas metal arc welding processes, where high speed imaging, and voltage and current monitoring were used to study the arc dynamic features. Standard metallographic procedures were used to study sidewall penetration, and the evolution of the heat affected zone during welding. It was found that cold wire injection stabilizes the arc wandering, decreasing sidewall penetration while almost doubling deposition. However, this also decreases penetration, and incomplete penetration was found in the cold wire specimens as a drawback. However, adjusting the groove geometry or changing the welding parameters would resolve this penetration issue. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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17 pages, 11632 KiB  
Article
Weibull Statistical Analysis of Strength Fluctuation for Failure Prediction and Structural Durability of Friction Stir Welded Al–Cu Dissimilar Joints Correlated to Metallurgical Bonded Characteristics
by Chung-Wei Yang and Shiau-Jiun Jiang
Materials 2019, 12(2), 205; https://doi.org/10.3390/ma12020205 - 09 Jan 2019
Cited by 22 | Viewed by 3312
Abstract
In this paper, dissimilar Al–Cu joints of AA1050H/C1100-Cu, AA6061-T6/C1100-Cu, and AA1050H/C2600-brass are successfully welded by a friction stir welding (FSW) process. The aim of the present study is not only to examine the tensile strength, but also to investigate the reliability, durability, and [...] Read more.
In this paper, dissimilar Al–Cu joints of AA1050H/C1100-Cu, AA6061-T6/C1100-Cu, and AA1050H/C2600-brass are successfully welded by a friction stir welding (FSW) process. The aim of the present study is not only to examine the tensile strength, but also to investigate the reliability, durability, and failure behaviors of joints as correlated with the metallurgical bonded microstructures of varied Al–Cu joints. Experimental evidence confirms that good welding quality for an FSW Al–Cu dissimilar joint is obtained when pure Cu and brass plates are positioned at the advancing side. Cross-sectional microstructures reveal that the AA6061-T6/C1100-Cu joint exhibits an extensive metallurgical bonded region with significant onion rings in the welding zone, whereas the AA1050H/C2600-brass joint generally displays a clear mechanical kissing bonded boundary at the joint interface. Al2Cu, Al4Cu9, and γ-Cu5Zn8 are major intermetallic compounds (IMCs) that are formed within the metallurgical bonded welding zone. The Weibull model provides a statistical method for assessing the failure mechanism of FSW Al–Cu joints. Better welding reliability and tensile properties with ductile dimpled ruptures are obtained for the Al–Cu joints with a typical metallurgical bonded zone. However, a mechanical kissing bonded interface and thick interfacial IMCs result in the deterioration of tensile strength with a brittle fracture and a rapid increase in the failure probability of Al–Cu joints. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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12 pages, 3609 KiB  
Article
Effect Range of the Material Constraint-I. Center Crack
by Jie Yang and Lei Wang
Materials 2019, 12(1), 67; https://doi.org/10.3390/ma12010067 - 25 Dec 2018
Cited by 12 | Viewed by 2827
Abstract
Material constraints are important factor effects on the fracture behavior of welded joints. The effect range of the material constraint is an important and interesting issue which needs to be clarified, including whether the effect range of a material constraint exists or not, [...] Read more.
Material constraints are important factor effects on the fracture behavior of welded joints. The effect range of the material constraint is an important and interesting issue which needs to be clarified, including whether the effect range of a material constraint exists or not, who will affect it, and whether the material constraint is affected by the no adjacent area or not. In this study, different basic models which reflect different single metallic welded joints, bimetallic welded joints and dissimilar metal welded joints were designed, and the fracture resistance curves and crack tip strain fields of the different models with various material constraints were calculated. Based on the results, the questions above were answered. This study has significance for developing solid mechanics, optimizing joint design, structure integrity assessment, and so on. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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16 pages, 20816 KiB  
Article
Calculation of the Intermetallic Layer Thickness in Cold Metal Transfer Welding of Aluminum to Steel
by Zahra Silvayeh, Bruno Götzinger, Werner Karner, Matthias Hartmann and Christof Sommitsch
Materials 2019, 12(1), 35; https://doi.org/10.3390/ma12010035 - 22 Dec 2018
Cited by 9 | Viewed by 3921
Abstract
The intermetallic layer, which forms at the bonding interface in dissimilar welding of aluminum alloys to steel, is the most important characteristic feature influencing the mechanical properties of the joint. In this work, horizontal butt-welding of thin sheets of aluminum alloy EN AW-6014 [...] Read more.
The intermetallic layer, which forms at the bonding interface in dissimilar welding of aluminum alloys to steel, is the most important characteristic feature influencing the mechanical properties of the joint. In this work, horizontal butt-welding of thin sheets of aluminum alloy EN AW-6014 T4 and galvanized mild steel DC04 was investigated. In order to predict the thickness of the intermetallic layer based on the main welding process parameters, a numerical model was created using the software package Visual-Environment. This model was validated with cold metal transfer (CMT) welding experiments. Based on the calculated temperature field inside the joint, the evolution of the intermetallic layer was numerically estimated using the software Matlab. The results of these calculations were confirmed by metallographic investigations using an optical microscope, which revealed spatial thickness variations of the intermetallic layer along the bonding interface. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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8 pages, 3043 KiB  
Article
CVD Diamond Interaction with Fe at Elevated Temperatures
by Sergei Zenkin, Aleksandr Gaydaychuk, Vitaly Okhotnikov and Stepan Linnik
Materials 2018, 11(12), 2505; https://doi.org/10.3390/ma11122505 - 10 Dec 2018
Cited by 7 | Viewed by 4252
Abstract
Chemical vapor deposition (CVD) diamond is a prospective thin film material for cutting tools applications due to the extreme combination of hardness, chemical inertness, and thermal conductivity. However, the CVD diamond cutting ability of ferrous materials is strongly limited due to its extreme [...] Read more.
Chemical vapor deposition (CVD) diamond is a prospective thin film material for cutting tools applications due to the extreme combination of hardness, chemical inertness, and thermal conductivity. However, the CVD diamond cutting ability of ferrous materials is strongly limited due to its extreme affinity to iron, cobalt, or nickel. The diamond–iron interaction and the diffusion behavior in this system are not well studied and are believed to be similar to the graphite–iron mechanism. In this article, we focus on the medium-temperature working range of 400–800 °C of a CVD diamond–Fe system and show that for these temperatures etching of diamond by Fe is not as strong as is generally accepted. The starting point of the diamond graphitization in contact with iron was found around 400 °C. Our results show that CVD diamond is applicable for the cutting of ferrous materials under medium-temperature conditions. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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12 pages, 6781 KiB  
Article
EBSD Investigation of the Microtexture of Weld Metal and Base Metal in Laser Welded Al–Li Alloys
by Li Cui, Zhibo Peng, Xiaokun Yuan, Dingyong He and Li Chen
Materials 2018, 11(12), 2357; https://doi.org/10.3390/ma11122357 - 23 Nov 2018
Cited by 8 | Viewed by 3751
Abstract
Autogenous laser welding of 5A90 Al–Li alloy sheets in a butt-joint configuration was carried out in this study. The microstructure characteristics of the weld metal and base metal in the horizontal surface and the transverse section of the welded joints were examined quantitatively [...] Read more.
Autogenous laser welding of 5A90 Al–Li alloy sheets in a butt-joint configuration was carried out in this study. The microstructure characteristics of the weld metal and base metal in the horizontal surface and the transverse section of the welded joints were examined quantitatively using electron back scattered diffraction (EBSD) technique. The results show that the weld metal in the horizontal surface and the transverse section exhibits similar grain structural features including the grain orientations, grain shapes, and grain sizes, whereas distinct differences in the texture intensity and misorientation distributions are observed. However, the base metal in the horizontal surface and the transverse section of the joints reveals the obvious different texture characteristics in terms of the grain orientation, grain morphology, predominate texture ingredients, distribution intensities of textures, and grain boundary misorientation distribution, resulting in the diversity of the microhardness in the base metal and the softening of the weld metal. However, the degree of the drop in the hardness of the weld metal is highly correlated to the microtexture developed in the base metal. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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13 pages, 6860 KiB  
Article
Effect of Welding Current on Weld Formation, Microstructure, and Mechanical Properties in Resistance Spot Welding of CR590T/340Y Galvanized Dual Phase Steel
by Xinge Zhang, Fubin Yao, Zhenan Ren and Haiyan Yu
Materials 2018, 11(11), 2310; https://doi.org/10.3390/ma11112310 - 17 Nov 2018
Cited by 17 | Viewed by 5604
Abstract
During resistance spot welding, the welding current is the most important process parameter, which determines the welding heat input and then has a great influence on the welding quality. In present study, the CR590T/340YDP galvanized dual phase steel widely used as automobile material [...] Read more.
During resistance spot welding, the welding current is the most important process parameter, which determines the welding heat input and then has a great influence on the welding quality. In present study, the CR590T/340YDP galvanized dual phase steel widely used as automobile material was carried out using resistance spot welding. The effect of welding current on the weld formation, microstructure, and mechanical properties was studied in detail. It was found that the quality of weld appearance decreased with the increase of welding current, and there was a Zn island on the weld surface. The microstructure of the whole resistance spot welded joint was inhomogeneity. The nugget zone consisted of coarse lath martensite and a little of ferrite with the columnar crystal morphology, and the microstructure of weld nugget became coarser when the welding current was higher. There was an optimum welding current value and the tensile strength reached the maximum. This investigation will provide the process guidance for automobile body production. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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16 pages, 6555 KiB  
Article
Simulation of Temperature Distribution and Microstructure Evolution in the Molten Pool of GTAW Ti-6Al-4V Alloy
by Min Zhang, Yulan Zhou, Chao Huang, Qiaoling Chu, Wenhui Zhang and Jihong Li
Materials 2018, 11(11), 2288; https://doi.org/10.3390/ma11112288 - 15 Nov 2018
Cited by 18 | Viewed by 4066
Abstract
In this paper, a three-dimensional (3D) finite element model was established by ABAQUS software to simulate the welding temperature field of a Ti-6Al-4V alloy under different welding currents based on a Gaussian heat source model. The model uses thermo-mechanical coupling analysis and takes [...] Read more.
In this paper, a three-dimensional (3D) finite element model was established by ABAQUS software to simulate the welding temperature field of a Ti-6Al-4V alloy under different welding currents based on a Gaussian heat source model. The model uses thermo-mechanical coupling analysis and takes into account the effects of convection and radiation on all weld surfaces. The microstructure evolution of the molten pool was calculated using the macro-micro coupling cellular automaton-finite different (CA-FD) method. It was found that with the increase of the welding current, the temperature in the central region of the moving heat source was improved and the weld bead became wider. Then, the dendritic morphology and solute concentration of the columnar to equiaxed transition (CET) in the weld molten pool was investigated. It is shown that fine equiaxed crystals formed around the columnar crystals tips during solidification. The coarse columnar crystals are produced with priority in the molten pool and their growth direction is in line with the direction of the negative temperature gradient. The effectiveness of the model was verified by gas tungsten arc welding experiments. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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12 pages, 7325 KiB  
Article
Role of Reversed Austenite Behavior in Determining Microstructure and Toughness of Advanced Medium Mn Steel by Welding Thermal Cycle
by Yunxia Chen, Honghong Wang, Huan Cai, Junhui Li and Yongqing Chen
Materials 2018, 11(11), 2127; https://doi.org/10.3390/ma11112127 - 29 Oct 2018
Cited by 8 | Viewed by 2880
Abstract
Reversed austenite transformation behavior plays a significant role in determining the microstructure and mechanical properties of heat affected zones of steels, involving the nucleation and growth of reversed austenite. Confocal Laser Scanning Microscope (CLSM) was used in the present work to in situ [...] Read more.
Reversed austenite transformation behavior plays a significant role in determining the microstructure and mechanical properties of heat affected zones of steels, involving the nucleation and growth of reversed austenite. Confocal Laser Scanning Microscope (CLSM) was used in the present work to in situ observe the reversed austenite transformation by simulating welding thermal cycles for advance 5Mn steels. No thermal inertia was found on cooling process after temperature reached the peak temperature of 1320 °C. Therefore, too large grain was not generated in coarse-grained heat-affected zone (CGHAZ). The pre-existing film retained austenite in base metal and acted as additional favorable nucleation sites for reversed austenite during the thermal cycle. A much great nucleation number led to the finer grain in the fine-grained heat-affected zone (FGHAZ). The continuous cooling transformation for CGHAZ and FGHAZ revealed that the martensite was the main transformed product. Martensite transformation temperature (Tm) was higher in FGHAZ than in CGHAZ. Martensite transformation rate was higher in FGHAZ than in CGHAZ, which is due to the different grain size and assumed atom (Mn and C) segregation. Consequently, the softer martensite was measured in CGHAZ than in FGHAZ. Although 10~11% austenite retained in FGHAZ, the possible Transformation Induced Plasticity (TRIP) effect at −60 °C test temperature may lower the impact toughness to some degree. Therefore, the mean absorbed energy of 31, 39 and 42 J in CGHAZ and 56, 45 and 36 J in FGHAZ were exhibited at the same welding heat input. The more stable retained austenite was speculated to improve impact toughness in heat-affected zone (HAZ). For these 5Mn steels, reversed austenite plays a significant role in affecting impact toughness of heat-affected zones more than grain size. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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14 pages, 4244 KiB  
Article
Microstructural Characterization and Mechanical Behavior of NiTi Shape Memory Alloys Ultrasonic Joints Using Cu Interlayer
by Wei Zhang, Sansan Ao, Joao Pedro Oliveira, Zhi Zeng, Yifei Huang and Zhen Luo
Materials 2018, 11(10), 1830; https://doi.org/10.3390/ma11101830 - 26 Sep 2018
Cited by 27 | Viewed by 4923
Abstract
NiTi shape memory alloys (SMAs) are a class of functional materials which can be significantly deformed and recover their original shape via a reversible martensitic phase transformation. Developing effective joining techniques can expand the application of SMAs in the medical and engineering fields. [...] Read more.
NiTi shape memory alloys (SMAs) are a class of functional materials which can be significantly deformed and recover their original shape via a reversible martensitic phase transformation. Developing effective joining techniques can expand the application of SMAs in the medical and engineering fields. In this study, ultrasonic spot welding (USW), a solid-state joining technique, was used to join NiTi sheets using a Cu interlayer in between the two joining sheets. The influence of USW process on the microstructural characteristics and mechanical behavior of the NiTi joints was investigated. Compared with conventional fusion welding techniques, no intermetallic compounds formed in the joints, which is extreme importance for this particular class of alloys. The joining mechanisms involve a combination of shear plastic deformation, mechanical interlocking and formation of micro-welds. A better bonding interface was obtained with higher welding energy levels, which contributed to a higher tensile load. An interfacial fracture mode occurred and the fracture surfaces exhibited both brittle and ductile-like characteristics with the existence of tear ridges and dimples. The fracture initiated at the weak region of the joint border and then propagated through it, leading to tearing of Cu foil at the fracture interface. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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8 pages, 2221 KiB  
Article
Coating Formation on Ti-6Al-4V Alloy by Micro Arc Oxidation in Molten Salt
by Alexander Sobolev, Israel Wolicki, Alexey Kossenko, Michael Zinigrad and Konstantin Borodianskiy
Materials 2018, 11(9), 1611; https://doi.org/10.3390/ma11091611 - 04 Sep 2018
Cited by 24 | Viewed by 4832
Abstract
Micro Arc Oxidation (MAO) is an electrochemical surface treatment process to produce oxide protective coatings on some metals. MAO is usually conducted in an aqueous electrolyte, which requires an intensive bath cooling and leads to the formation of a coating containing impurities that [...] Read more.
Micro Arc Oxidation (MAO) is an electrochemical surface treatment process to produce oxide protective coatings on some metals. MAO is usually conducted in an aqueous electrolyte, which requires an intensive bath cooling and leads to the formation of a coating containing impurities that originate in the electrolyte. In the current work, we applied an alternative ceramic coating to the Ti-6Al-4V alloy using the MAO process in molten nitrate salt at a temperature of 280 °C. The obtained coating morphology, chemical and phase composition, and corrosion resistance were investigated and described. The obtained results showed that a coating of 2.5 µm was formed after 10 min of treatment, containing titanium oxide and titanium‒aluminum intermetallic phases. Morphological examination indicated that the coating is free of cracks and contains round, homogeneously distributed pores. Corrosion resistance testing indicated that the protective oxide coating on Ti alloy is 20 times more resistive than the untreated alloy. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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8 pages, 2967 KiB  
Article
Effect of Temperature and Hold Time of Induction Brazing on Microstructure and Shear Strength of Martensitic Stainless Steel Joints
by Yunxia Chen and Haichao Cui
Materials 2018, 11(9), 1586; https://doi.org/10.3390/ma11091586 - 01 Sep 2018
Cited by 7 | Viewed by 3289
Abstract
1Cr12Mo martensitic stainless steel is widely used for intermediate and low-pressure steam turbine blades in fossil-fuel power plants. A nickel-based filler metal (SFA-5.8 BNi-2) was used to braze 1Cr12Mo in an Ar atmosphere. The influence of brazing temperature and hold time on the [...] Read more.
1Cr12Mo martensitic stainless steel is widely used for intermediate and low-pressure steam turbine blades in fossil-fuel power plants. A nickel-based filler metal (SFA-5.8 BNi-2) was used to braze 1Cr12Mo in an Ar atmosphere. The influence of brazing temperature and hold time on the joints was studied. Microstructure of the joints brazed, element distribution and shear stress were evaluated at different brazing temperatures, ranging from 1050 °C to 1120 °C, with holding times of 10 s, 30 s, 50 s and 90 s. The results show that brazing joints mainly consist of the matrix of the braze alloy, the precipitation, and the diffusion affected zone. The filler metal elements diffusion is more active with increased brazing temperature and prolonged hold time. The shear strength of the brazed joints is greater than 250 MPa when the brazing temperature is 1080 °C and the hold time is 30 s. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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15 pages, 6486 KiB  
Article
Properties and Structure of Deposited Nanocrystalline Coatings in Relation to Selected Construction Materials Resistant to Abrasive Wear
by Jacek Górka, Artur Czupryński, Marcin Żuk, Marcin Adamiak and Adam Kopyść
Materials 2018, 11(7), 1184; https://doi.org/10.3390/ma11071184 - 10 Jul 2018
Cited by 22 | Viewed by 4760
Abstract
Presented in this work are the properties and structure characteristics of MMA (Manual Metal Arc) deposited nanocrystalline coatings (Fe-Cr-Nb-B) applied to an iron nanoalloy matrix on an S355N steel substrate in relation to selected construction materials resistant to abrasive wear currently used in [...] Read more.
Presented in this work are the properties and structure characteristics of MMA (Manual Metal Arc) deposited nanocrystalline coatings (Fe-Cr-Nb-B) applied to an iron nanoalloy matrix on an S355N steel substrate in relation to selected construction materials resistant to abrasive wear currently used in industry. The obtained overlay welds were subjected to macro and microscopic metallographic examinations; grain size was determined by X-ray diffraction (XRD), and chemical composition of precipitates was determined by energy-dispersive X-ray spectroscopy (EDS) during scanning electron microscopy (SEM). The size of the crystalline grains of the Fe-Cr-Nb-B nanocrystalline microstructure was analyzed using an Xpert PRO X-ray diffractometer. Analysis of the test results of the obtained layers of arc-welded Fe-Cr-Nb-B-type alloy confirmed that the obtained layers are made of crystallites with a size of 20 nm, which classifies these layers as nanocrystalline. The obtained nanocrystalline coatings were assessed by hardness and with the use of metal-mineral abrasion testing. The results of the coatings’ properties tests were compared to HARDOX 400 alloy steel. Full article
(This article belongs to the Special Issue Welding, Joining and Coating of Metallic Materials)
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