scholarly journals A Compact Review of Laser Welding Technologies for Amorphous Alloys

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1690
Author(s):  
Jian Qiao ◽  
Peng Yu ◽  
Yanxiong Wu ◽  
Taixi Chen ◽  
Yixin Du ◽  
...  

Amorphous alloys have emerged as important materials for precision machinery, energy conversion, information processing, and aerospace components. This is due to their unique structure and excellent properties, including superior strength, high elasticity, and excellent corrosion resistance, which have attracted the attention of many researchers. However, the size of the amorphous alloy components remains limited, which affects industrial applications. Significant developments in connection with this technology are urgently needed. Laser welding represents an efficient welding method that uses a laser beam with high energy-density for heating. Laser welding has gradually become a research hotspot as a joining method for amorphous alloys due to its fast heating and cooling rates. In this compact review, the current status of research into amorphous-alloy laser welding technology is discussed, the influence of technological parameters and other welding conditions on welding quality is analyzed, and an outlook on future research and development is provided. This paper can serve as a useful reference for both fundamental research and engineering applications in this field.

2018 ◽  
Vol 10 (10) ◽  
pp. 3560 ◽  
Author(s):  
Xian Zhao ◽  
Siqi Wang ◽  
Xiaoyue Wang

In order to satisfy the increasing energy demand and deal with the environmental problem caused by the conventional energy vehicle; the new energy vehicle (NEV), especially the electric vehicle (EV), has attracted increasing attention and the corresponding research has developed rapidly in recent years. The electric vehicle requires a battery with high energy density and frequent charging. In order to ensure high performance of the electric vehicle; the reliability of its charging system is extremely important. In this paper; an overview of the research on electric vehicle charging system reliability from 1998 to 2017 is presented from a bibliometric perspective. This study provides a comprehensive analysis of the current research climate and the emerging trends from the following four aspects: basic characteristics of publication outputs; including annual publication outputs and document types; collaboration analysis of countries/territories; institutions and authors; co-citation analysis of cited authors and cited references; co-occurrence analysis of subjects and keywords. By using CiteSpace; the collaboration relationship; co-citation and co-occurrence networks are shown clearly. According to the analysis results; studies in this research field will keep developing rapidly in the near future and several future research directions are proposed in the conclusions.


2021 ◽  
Vol 1027 ◽  
pp. 42-47
Author(s):  
Hao Ran Zheng

Metal lithium anodes, with extremely high specific capacity, low density, and lowest potential, are considered to be the most promising anode materials for next-generation high-energy density batteries. However, in the process of repeated plating and stripping of lithium, lithium dendrites are easily grown on the surface of the metal lithium anode, which greatly reduces the capacity of the battery, even causes hidden safety risks and shortens the battery life. This paper reviews the modification methods of lithium anodes based on the growth process of lithium dendrites, and introduces several current modification methods, including electrolyte additives, artificial SEI and new structure of lithium anodes. Finally, the future research direction and development trend of metal lithium anodes are prospected.


Author(s):  
David Chiaramonti ◽  
Anja Oasmaa ◽  
Yrjo¨ Solantausta

Biomass fast-pyrolysis oil (PO) is a liquid biofuel derived from lignocellulosic biomass: it offers several advantages compared to the direct us of solid bio fuels, such as high energy density, storability and transportability typical of liquid fuels, possibility to use the fuel in engines and turbines, easier downscaling of plants (which is a very important aspect for decentralized energy generation schemes). In addition, PO is the lowest cost biofuel, thus offering the possibility to penetrate also the large scale power generation market. Biomass POs have been studied and applications tested for many years, either for heat generation in medium-scale boilers or power generation. The present works reviews and analyses the most relevant experiences carried out so far and published results in power production from biomass PO. Power generation systems (PGS) which are here examined are gas turbines, diesel engines, stirling engines, as well as co-firing applications in large scale power plants (coal or natural gas plants). The main techniques for upgrading this biofuel and their impact on technologies are also shortly introduced and considered. The current status of development for each PO-based power generation option is discussed. This review work showed that long term demonstration (either technical or economical) is however still needed, even for the most developed technologies (use of PO in modified gas turbines and cofiring in natural gas stations): projects are on going to achieve long term demonstration.


Author(s):  
Dominik Scholtes ◽  
Stefan Seelecke ◽  
Gianluca Rizzello ◽  
Paul Motzki

Abstract Within industrial manufacturing most processing steps are accompanied by transporting and positioning of workpieces. The active interfaces between handling system and workpiece are industrial grippers, which often are driven by pneumatics, especially in small scale areas. On the way to higher energy efficiency and digital factories, companies are looking for new actuation technologies with more sensor integration and better efficiencies. Commonly used actuators like solenoids and electric engines are in many cases too heavy and large for direct integration into the gripping system. Due to their high energy density shape memory alloys (SMA) are suited to overcome those drawbacks of conventional actuators. Additionally, they feature self-sensing abilities that lead to sensor-less monitoring and control of the actuation system. Another drawback of conventional grippers is their design, which is based on moving parts with linear guides and bearings. These parts are prone to wear, especially in abrasive environments. This can be overcome by a compliant gripper design that is based on flexure hinges and thus dispenses with joints, bearings and guides. In the presented work, the development process of a functional prototype for a compliant gripper driven by a bistable SMA actuation unit for industrial applications is outlined. The focus lies on the development of the SMA actuator, while the first design approach for the compliant gripper mechanism with solid state joints is proposed. The result is a working gripper-prototype which is mainly made of 3D-printed parts. First results of validation experiments are discussed.


Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1523
Author(s):  
Lilian Schwich ◽  
Michael Küpers ◽  
Martin Finsterbusch ◽  
Andrea Schreiber ◽  
Dina Fattakhova-Rohlfing ◽  
...  

In the coming years, the demand for safe electrical energy storage devices with high energy density will increase drastically due to the electrification of the transportation sector and the need for stationary storage for renewable energies. Advanced battery concepts like all-solid-state batteries (ASBs) are considered one of the most promising candidates for future energy storage technologies. They offer several advantages over conventional Lithium-Ion Batteries (LIBs), especially with regard to stability, safety, and energy density. Hardly any recycling studies have been conducted, yet, but such examinations will play an important role when considering raw materials supply, sustainability of battery systems, CO2 footprint, and general strive towards a circular economy. Although different methods for recycling LIBs are already available, the transferability to ASBs is not straightforward due to differences in used materials and fabrication technologies, even if the chemistry does not change (e.g., Li-intercalation cathodes). Challenges in terms of the ceramic nature of the cell components and thus the necessity for specific recycling strategies are investigated here for the first time. As a major result, a recycling route based on inert shredding, a subsequent thermal treatment, and a sorting step is suggested, and transferring the extracted black mass to a dedicated hydrometallurgical recycling process is proposed. The hydrometallurgical approach is split into two scenarios differing in terms of solubility of the ASB-battery components. Hence, developing a full recycling concept is reached by this study, which will be experimentally examined in future research.


2011 ◽  
Vol 314-316 ◽  
pp. 941-944 ◽  
Author(s):  
Xiang Dong Gao ◽  
Qian Wen ◽  
Seiji Katayama

During deep penetration laser welding, a keyhole is formed in the molten pool due to the intense recoil pressure of evaporation. The formation of the keyhole leads to a deep penetration weld with a high aspect ratio and this is the most advantageous feature of welding by high-energy-density beams. The configuration and characteristics of a keyhole are related to the welding stability. In a fiber laser butt-joint welding of Type 304 austenitic stainless steel plate with a high power 10 kW continuous wave fiber laser, an infrared sensitive high-speed video camera was used to capture the dynamic images of the molten pools. The configurations of a keyhole were analyzed through image processing techniques such as median filtering, wiener filtering and gray level threshold segmentation to obtain the edge of a keyhole. The width and the area of a keyhole were defined as the keyhole characteristic parameters, and the deviation between the laser beam and weld center as a parameter reflecting the welding stability. By analyzing the change of the keyhole characteristic parameters during welding process, it was found that these parameters were related to the welding stability. Welding experimental results and analysis of the keyhole characteristic parameters confirmed that the welding stability could be monitored and distinguished by a keyhole configuration during high-power fiber laser welding.


2017 ◽  
Vol 727 ◽  
pp. 670-677 ◽  
Author(s):  
Jun Zhang ◽  
Ying Li Zhu ◽  
Gang Qi ◽  
Jian Yu Li

Low temperature fuel cells are promising environment-friendly energy conversion systems with high energy density and efficiency to be used as components of electronic devices for stationary and portable applications. In this paper, the key materials of the three types low temperature fuel cells are introduced, and the most recent advances related to the key materials and their character are reviewed. The current status of materials for electrolyte, catalyst and electrode materials is focused on.


Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 279 ◽  
Author(s):  
Qi Zhu ◽  
Miaoxia Xie ◽  
Xiangtao Shang ◽  
Geng An ◽  
Jun Sun ◽  
...  

Owing to its potential application prospect in novel accident tolerant fuel, molybdenum alloys and their welding technologies have gained great importance in recent years. The challenges of welding molybdenum alloys come from two aspects: one is related to its powder metallurgy manufacturing process, and the other is its inherent characteristics of refractory metal. The welding of powder metallurgy materials has been associated with issues such as porosity, contamination, and inclusions, at levels which tend to degrade the service performances of a welded joint. Refractory metals usually present poor weldability due to embrittlement of the fusion zone as a result of impurities segregation and the grain coarsening in the heat-affected zone. A critical review of the current state of the art of welding Mo alloys components is presented. The advantages and disadvantages of the various methods, i.e., electron-beam welding (EBW), tungsten-arc inert gas (TIG) welding, laser welding (LW), electric resistance welding (ERW), and brazing and friction welding (FW) in joining Mo and Mo alloys, are discussed with a view to imagine future directions. This review suggests that more attention should be paid to high energy density laser welding and the mechanism and technology of welding Mo alloys under hyperbaric environment.


2011 ◽  
Vol 117-119 ◽  
pp. 402-408
Author(s):  
Shazarel Shamsudin ◽  
Phoon Chee Yoon

Product with low cost, lightweight and enhanced mechanical properties were the main reasons welding dissimilar materials thrived by most of the industries. The laser welding technique which has high-energy density beam was found suitable of carrying this task. This paper attempts to investigate welding of AISI 304 stainless steel to AISI 1008 steel through Nd:YAG pulse laser method. The main objective of this study was to find out the weldability of these materials and investigate the mechanical properties of the welded butt joints. Peak power, pulse duration and weld speed combinations were carefully selected with the aims of producing weld with a good tensile strength, minimum heat affected zone (HAZ) and acceptable welding profile. Response surface methodology (RSM) approach was adopted as statistical design technique for tensile strength optimization. Statistical based mathematical model was developed to describe effects of each process parameters on the weld tensile strength and for response prediction within the parameter ranges. The microstructure of the weld and heat affected zones were observed via optical microscope. The results indicate the developed model can predict the response within ±9% of error from the actual values.


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