scholarly journals Microstructure Evolution and Strengthening Mechanism of Galvanized Steel/Mg Alloy Joint Obtained by Ultrasonic Vibration-Assisted Welding Process

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1674
Author(s):  
Fangzhou Yang ◽  
Bing Liu
Keyword(s):  
Ultrasonic Vibration ◽  
Acoustic Streaming ◽  
Welding Process ◽  
Strengthening Mechanism ◽  
Fusion Welding ◽  
Galvanized Steel ◽  
Mg Alloy ◽  
Ultrasonic Power ◽  
Average Grain Size ◽  
Joining Strength

A novel ultrasonic vibration-assisted welding (UVAW) process was used to achieve reliable joining of galvanized steel and Mg alloy. The effects of the UVAW technique on the microstructure and mechanical properties of galvanized steel/Mg alloy weldment were studied in detail. The introduction of ultrasonic vibration can ameliorate the wetting of welds and eliminate porosity defects. A refined microstructure of the fusion welding zone with an average grain size of 39 ± 1.7 µm was obtained and attributed to cavitation and acoustic streaming caused by the UVAW process. The grain refinement led to an increase in the microhardness and joining strength of the galvanized steel/Mg alloy weldment. Under the ultrasonic power of 0.9 kW and a current of 65 A, the maximum joining strength of the ultrasound-treated galvanized steel/Mg alloy joint was 251 ± 4.1 MPa, which was a 14.6% increase over the joint without ultrasonic treatment.

Strengthening Mechanism of TiB2-TiC Complex Phases Coated Electrode

2012 ◽  
Vol 433-440 ◽  
pp. 251-255 ◽  
Author(s):  
Ping Luo ◽  
Shi Jie Dong ◽  
Zhang Qiang Mei ◽  
Zhi Xiong Xie
Keyword(s):  
Failure Mechanism ◽  
Current Density ◽  
Spot Welding ◽  
Single Phase ◽  
Welding Process ◽  
Strengthening Mechanism ◽  
Galvanized Steel ◽  
Steel Weld ◽  
Galvanized Steels ◽  
Coated Electrode

TiB2-TiC complex phases coating deposited onto the surface of electrodes by electro-spark deposition (ESD) in order to prolong the life of single phase coated electrode (TiB2 or TiC) during resistance welding of galvanized steels. The microstructures and TiB2-TiC complex phases coatings were characterized by SEM and XRD. The results indicate that life of TiB2-TiC complex phases coated electrode is prolonged significantly than life of single-phase coated electrode （TiB2 or TiC ）, failure mechanism of TiB2-TiC complex phases coated electrode is mainly wear to cause diameter increase on electrode tip, which results in lower current density during welding process, and then nugget size cannot satisfy the requirement of resistance spot welding. The failure mechanism of TiB2-TiC complex phases coated electrode is obviously different from uncoated electrode, the failure mechanism of uncoated electrode is wear and alloying between electrode tip surface and molten Zn on galvanized steel weld surface.

scholarly journals Effect of Vanadium Reinforcement on the Microstructure and Mechanical Properties of Magnesium Matrix Composites

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 806
Author(s):  
Liqing Sun ◽  
Shuai Sun ◽  
Haiping Zhou ◽  
Hongbin Zhang ◽  
Gang Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Milling Process ◽  
Mg Alloy ◽  
Matrix Composites ◽  
Magnesium Matrix Composites ◽  
Pinning Effect ◽  
Average Grain Size ◽  
The Matrix ◽  
Hot Press Sintering

In this work, vanadium particles (VP) were utilized as a novel reinforcement of AZ31 magnesium (Mg) alloy. The nanocrystalline (NC) AZ31–VP composites were prepared via mechanical milling (MM) and vacuum hot-press sintering. During the milling process, the presence of VP contributed to the cold welding and fracture mechanism, resulting in the acceleration of the milling process. Additionally, increasing the VP content accelerated the grain refinement of the matrix during the milling process. After milling for 90 h, the average grain size of AZ31-X wt % Vp (X = 5, 7.5, 10) was refined to only about 23 nm, 19 nm and 16 nm, respectively. In the meantime, VP was refined to sub-micron scale and distributed uniformly in the matrix, exhibiting excellent interfacial bonding with the matrix. After the sintering process, the average grain size of AZ31-X wt % VP (X = 5, 7.5, 10) composites still remained at the NC scale, which was mainly caused by the pinning effect of VP. Besides that, the porosity of the sintered composites was no more than 7.8%, indicating a good densification effect. As a result, there was little difference between the theoretical and real density. Compared to as-cast AZ31 Mg alloy, the microhardness of sintered AZ31-X wt % VP (X = 5, 7.5, 10) composites increased by 65%, 87% and 96%, respectively, owing to the strengthening mechanisms of grain refinement strengthening, Orowan strengthening and load-bearing effects.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

scholarly journals Recommendations for an Open Science approach to welding process research data

2021 ◽  
Author(s):  
Cagtay Fabry ◽  
Andreas Pittner ◽  
Volker Hirthammer ◽  
Michael Rethmeier
Keyword(s):  
Domain Knowledge ◽  
Knowledge Exchange ◽  
Welding Process ◽  
Open Science ◽  
Research Data ◽  
Fusion Welding ◽  
File Format ◽  
Data Format ◽  
Science Practices ◽  
Science Community

AbstractThe increasing adoption of Open Science principles has been a prevalent topic in the welding science community over the last years. Providing access to welding knowledge in the form of complex and complete datasets in addition to peer-reviewed publications can be identified as an important step to promote knowledge exchange and cooperation. There exist previous efforts on building data models specifically for fusion welding applications; however, a common agreed upon implementation that is used by the community is still lacking. One proven approach in other domains has been the use of an openly accessible and agreed upon file and data format used for archiving and sharing domain knowledge in the form of experimental data. Going into a similar direction, the welding community faces particular practical, technical, and also ideological challenges that are discussed in this paper. Collaboratively building upon previous work with modern tools and platforms, the authors motivate, propose, and outline the use of a common file format specifically tailored to the needs of the welding research community as a complement to other already established Open Science practices. Successfully establishing a culture of openly accessible research data has the potential to significantly stimulate progress in welding research.

scholarly journals Porosity Characteristics and Effect on Tensile Shear Strength of High-Strength Galvanized Steel Sheets after the Gas Metal Arc Welding Process

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1077 ◽  
Author(s):  
Seungmin Shin ◽  
Sehun Rhee
Keyword(s):  
Shear Strength ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
High Strength ◽  
Galvanized Steel ◽  
Tensile Shear Strength ◽  
Tensile Shear ◽  
Tensile Test Specimen ◽  
Metal Arc Welding

In this study, lap joint experiments were conducted using galvanized high-strength steel, SGAFH 590 FB 2.3 mmt, which was applied to automotive chassis components in the gas metal arc welding (GMAW) process. Zinc residues were confirmed using a semi-quantitative energy dispersive X-ray spectroscopy (EDS) analysis of the porosity in the weld. In addition, a tensile shear test was performed to evaluate the weldability. Furthermore, the effect of porosity defects, such as blowholes and pits generated in the weld, on the tensile shear strength was experimentally verified by comparing the porosity at the weld section of the tensile test specimen with that measured through radiographic testing.

A Simplified Numerical Approach for Finding the Temperature Distribution in Submerged arc Welding Process

2012 ◽  
Vol 622-623 ◽  
pp. 315-318
Author(s):  
Aparesh Datta ◽  
Subodh Debbarma ◽  
Subhash Chandra Saha
Keyword(s):  
Temperature Distribution ◽  
Heat Source ◽  
Arc Welding ◽  
Welding Process ◽  
Numerical Approach ◽  
High Heat ◽  
Submerged Arc Welding ◽  
Fusion Welding ◽  
Arc Welding Process ◽  
Submerged Arc

The quality of joining has assumed a greater role in fabrication of metal in recent years, because of the development of new alloys with tremendously increased strength and toughness. Submerged arc welding is a high heat input fusion welding process in which weld is produced by moving localized heat source along the joint. The weld quality in turn affected by thermal cycle that the weldment experiences during the welding. In the present study a simple comprehensive mathematical model has been developed using a moving heat source and analyzing the temperature on one section and then the temperature distribution of other section are correlated with time delay with reference analyzed section.

Evolutions of Microstructure for Multilayered Al-Mg Alloy Composites by Accumulation Roll Bonding (ARB) Process

2011 ◽  
Vol 411 ◽  
pp. 527-531
Author(s):  
Bing Zhang ◽  
Zhong Wei Chen ◽  
Shou Qian Yuan ◽  
Tian Li Zhao
Keyword(s):  
Multilayer Structure ◽  
Optical Microscope ◽  
Alloy Layer ◽  
Mg Alloy ◽  
Micro Hardness ◽  
Roll Bonding ◽  
Fine Grained ◽  
Hardness Tester ◽  
Average Grain Size ◽  
Evolution Of Microstructure

In this paper, accumulative roll bonding (ARB) has been used to prepare the Al/Mg alloy multilayer structure composite materials with 1060Al sheet and MB2 sheet. The evolution of microstructure of the cladding materials during ARB processes was observed by optical microscope, scanning electron microscopy, and micro-hardness was measured by micro-hardness tester. The results show that a multilayer structure material of Al/Mg alloy with excellent bonding characteristics and fine grained microstructure was prepared by ARB processes. With the ARB cycles increasing, Mg alloy layer in multilayer composite material was necked and fractured, and the hardness of the Al and Mg alloy was increased. Average grain size was less than 1μm after ARB4 cycles.

Microstructure and mechanical property of TiB reinforced Ti matrix composites fabricated by ultrasonic vibration-assisted laser engineered net shaping

2019 ◽  
Vol 25 (3) ◽  
pp. 581-591 ◽  
Author(s):  
Fuda Ning ◽  
Yingbin Hu ◽  
Weilong Cong
Keyword(s):  
Ultrasonic Vibration ◽  
Acoustic Streaming ◽  
Nonlinear Effects ◽  
Small Variation ◽  
Microstructural Characterization ◽  
Matrix Composites ◽  
Heterogeneous Distribution ◽  
Content Type ◽  
Laser Engineered Net Shaping ◽  
Net Shaping

Purpose The purpose of this paper is to identify if the implementation of ultrasonic vibration in laser engineered net shaping (LENS) process can help to reduce internal weaknesses such as porosity, coarse primary TiB whisker and heterogeneous distribution of TiB reinforcement in the LENS-fabricated TiB reinforced Ti matrix composites (TiB-TMC) parts. Design/methodology/approach An experimental investigation is performed to achieve the results for comparative studies under different fabrication conditions through quantitative data analysis. An approach of microstructural characterization and mechanical testing is conducted to obtain the output attributes. In addition, the theoretical analysis of the physics of ultrasonic vibration in the melting materials is presented to explain the influences of ultrasonic vibration on the microstructural evolution occurred in the part fabrication. Findings Because of the nonlinear effects of acoustic streaming and cavitation induced by ultrasonic vibration, porosity is significantly reduced and a relatively small variation of pore sizes is achieved. Ultrasonic vibration also causes the formation of smaller TiB whiskers that distribute along grain boundaries with a homogeneous dispersion. Additionally, a quasi-continuous network (QCN) microstructure is considerably finer than that produced by LENS process without ultrasonic vibration. The refinements of both reinforcing TiB whiskers and QCN microstructural grains further improve the microhardness of TiB-TMC parts. Originality/value The novel ultrasonic vibration-assisted (UV-A) LENS process of TiB-TMC is conducted in this work for the first time to improve the process performance and part quality.

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