scholarly journals Dissimilar Materials Welding with a Standoff-Free Vaporizing Foil Actuator between TRIP 1180 Steel Sheets and AA5052 Alloy

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4969
Author(s):  
Yuhyeong Jeong ◽  
Giseung Shin ◽  
Choo Woong ◽  
Jeoung Han Kim ◽  
Jonghun Yoon
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Dissimilar Materials ◽  
Input Energy ◽  
High Speed Impact ◽  
Steel Sheets ◽  
Welding Interface ◽  
Welding Strength ◽  
Grade Steel ◽  
Optimum Input

This paper mainly demonstrates an advanced type of the vaporizing foil actuator welding (VFAW) process between GPa-grade steel (TRIP1180) and aluminum alloy (AA5052-H32) without applying standoff. To secure a flying distance during the VFAW process, the preformed target sheet shaped like a circular indentation has been utilized. It is necessary to optimize process parameters integrated with geometrical design of the preform since the welding strength can be decreased beyond the optimum input energy in the standoff-free VFAW process. The welded surface was evaluated by SEM-EDS, XRD, EBDS, and TEM to analyze the welding mechanism and composition at the welding interface. The diffusion zone including the AlFe3 phase was observed at the welded interface which has high grain density due to the high-speed impact by increasing the welding strength, which leads to the perfect welding between the dissimilar materials.

Microstructure and Joint Strength of Similar- and Dissimilar Lap Joints Fabricated by Several Advanced Solid-State Welding Methods

2010 ◽  
Vol 654-656 ◽  
pp. 596-601 ◽  
Author(s):  
Shinji Kumai ◽  
Mitsuhiro Watanabe ◽  
Keyan Feng
Keyword(s):  
Aluminum Alloy ◽  
Solid State ◽  
High Speed ◽  
Joint Strength ◽  
Lap Joints ◽  
Back Surface ◽  
Magnetic Pulse ◽  
Oblique Collision ◽  
Friction Stir ◽  
Steel Sheets

Both similar- and dissimilar metal joints, which are difficult to be welded by using ordinary fusion welding methods, were successfully obtained by using several advanced high-speed solid-state joining methods. (1) Al/Al, Cu/Cu, Al/Fe(Steel), Al/Cu, Al/Ni, Cu/Ni and Al/Bulk metallic glass lap joints were magnetic pulse welded by means of mutual high-speed oblique collision of metal sheets at a high speed of about 500m/s. (2) 2xxx aluminum alloy pins were stud-welded to 5xxx alloy aluminum sheets and several kinds of plated steel sheets at a high speed by using a specially designed discharge circuit. The welding was achieved within a few milliseconds without producing any weld marks on the back surface of the plate. (3) 6022 aluminum alloy sheets were friction stir spot welded to steel sheets and various kinds of galvanized and aluminum-plated steel sheets. The welding was achieved within a few seconds. For those joints, joint strength and characteristic joint interface morphology were investigated.

scholarly journals Effect of high-speed impact compression on natural aging and subsequent artificial aging of a 6061 aluminum alloy

2015 ◽  
Vol 65 (12) ◽  
pp. 617-621
Author(s):  
Tomo Ogura ◽  
Keitaro Horikawa ◽  
Yuki Kitani ◽  
Mami Mihara ◽  
Seongnyeong Kim ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Artificial Aging ◽  
Natural Aging ◽  
Impact Compression ◽  
6061 Aluminum Alloy ◽  
High Speed Impact

scholarly journals Microstructure Evolution of 5052 Aluminum Sheet in Electromagnetic High-Speed Impact

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 564
Author(s):  
Fei Feng ◽  
Jianjun Li ◽  
Yunjun Zhang ◽  
Liang Huang ◽  
Hongliang Su ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Deformation Mechanism ◽  
High Speed ◽  
Alloy Sheet ◽  
Electromagnetic Forming ◽  
Aluminum Alloy Sheet ◽  
High Speed Impact ◽  
Forming Technology ◽  
High Speed Forming ◽  
Microscopic Deformation

Electromagnetic forming (EMF) is a high-speed forming technology, which can not only improve the formability of hard-to-form materials but also reduce springback. Electromagnetic high-speed impact can further improve the formability compared with electromagnetic free forming. The microscopic deformation mechanism of electromagnetic high-speed impact of aluminum alloy is discussed in this paper. The microstructures of electromagnetic high-speed impact of an aluminum alloy sheet were characterized. The microscopic deformation mechanisms of electromagnetic forming and electromagnetic high-speed impact were shown, respectively. The research results showed that electromagnetic high-speed impact could significantly improve the microhardness of the workpiece. The grains broke up and then became small subgrains during electromagnetic high-speed impact. The deformation mechanism was dominated by dislocation cross slip under electromagnetic high-speed impact.

Laser High-Speed Impact Composite Forming of Aluminum/Aluminum

2016 ◽  
Vol 723 ◽  
pp. 196-201
Author(s):  
Hong Feng Zhang ◽  
Xiao Wang ◽  
Xu Dong Ren ◽  
Shuai Gao ◽  
Hui Xia Liu
Keyword(s):  
Surface Morphology ◽  
High Speed ◽  
Laser Energy ◽  
Three Dimensional ◽  
Maximum Deformation ◽  
Experiment Platform ◽  
High Speed Impact ◽  
Composite Forming ◽  
Welding Interface ◽  
Digital Microscope

Based on the laser-driven flyer micro forming and laser high-speed impact welding, this paper put forward the laser high-speed impact synchronous welding and forming new process, and builds the compound welding experiment platform. The three-dimensional deep field digital microscope of KEYENCE VHX-1000C was used to measure the surface morphology and the maximum deformation depth of the welding and formingsamples. By observing the surface morphology of the sample, it was found that strong plastic deformation occurred on the surface of the materials and well reproduced the shape of the mold. When the laser energy was below 4.5J, the maximum deformation depth of the samples increased with the laser energy. However, the maximum deformation depth decreased due to the spring back phenomenon when the laser energy was larger than 4.5J. The Axio CSM 700 confocal microscope was used to measure the morphology of the welding interface. The cross profile of the welding interface showed that most regions had been welded and the welding interface was nearly flat.

scholarly journals Effect of High-Speed Impact Compression on Natural Aging and Subsequent Artificial Aging of a 6061 Aluminum Alloy

2016 ◽  
Vol 57 (8) ◽  
pp. 1282-1286
Author(s):  
Tomo Ogura ◽  
Keitaro Horikawa ◽  
Yuki Kitani ◽  
Mami Miara ◽  
SeongNyeong Kim ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Artificial Aging ◽  
Natural Aging ◽  
Impact Compression ◽  
6061 Aluminum Alloy ◽  
High Speed Impact

Inline Rolling of 5182 Aluminum Alloy Strip Cast by a Vertical Type High Speed Twin Roll Caster

2010 ◽  
Vol 139-141 ◽  
pp. 477-480
Author(s):  
Ryoji Nakamura ◽  
Shuya Hanada ◽  
Shinji Kumai ◽  
Hisaki Watari
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Rolling Speed ◽  
Center Line ◽  
Alloy Strip ◽  
Ripple Mark ◽  
Roll Casting ◽  
Strip Cast ◽  
Twin Roll Caster ◽  
Twin Roll

An inline hot rolling was operated on 5182 aluminum alloy strip cast using a vertical type high speed caster (VHSTRC) at the speed of 60 m/min. A porosity existing at center line of the thickness and a ripple mark on the surface, these are typical defects of the strip cast by the VHSTRC, could be improved by the inline rolling. The rolling speed was as same as the roll-casting-speed of 60m/min. The temperature of the strip, when the inline rolling was operated, was 450oC. The reduction of the strip of the inline rolling was 35%.

scholarly journals Energy Absorption Characteristics of PVC Coarse Aggregate Concrete under Impact Load

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Shi Hu ◽  
Huaming Tang ◽  
Shenyao Han
Keyword(s):  
Compressive Strength ◽  
Energy Absorption ◽  
High Speed ◽  
Coarse Aggregate ◽  
Specific Energy Absorption ◽  
Low Speed ◽  
High Speed Impact ◽  
Aggregate Content ◽  
Dynamic Compressive Strength ◽  
Absorption Characteristics

AbstractIn this paper, polyvinyl chloride (PVC) coarse aggregate with different mixing contents is used to solve the problems of plastic pollution, low energy absorption capacity and poor damage integrity, which provides an important reference for PVC plastic concrete used in the initial support structures of highway tunnels and coal mine roadway. At the same time, the energy absorption characteristics and their relationship under different impact loads are studied, which provides an important reference for predicting the energy absorption characteristics of concrete under other PVC aggregate content or higher impact speed. This study replaced natural coarse aggregate in concrete with different contents and equal volume of well-graded flaky PVC particles obtained by crushing PVC soft board. Also, slump, compression, and splitting strength tests, a free falling low-speed impact test of steel balls and a high-speed impact compression test of split Hopkinson pressure bar (SHPB) were carried out. Results demonstrate that the static and dynamic compressive strength decreases substantially, and the elastic modulus and slump decrease slowly with the increase of the mixing amount of PVC aggregate (0–30%). However, the energy absorption rate under low-speed impact and the specific energy absorption per MPa under high-speed impact increase obviously, indicating that the energy absorption capacity is significantly enhanced. Regardless of the mixing amount of PVC aggregate, greater strain rate can significantly enhance the dynamic compressive strength and the specific energy absorption per MPa. After the uniaxial compression test or the SHPB impact test, the relative integrity of the specimen is positively correlated with the mixing amount of PVC aggregate. In addition, the specimens are seriously damaged with the increase of the impact strain rate. When the PVC aggregate content is 20%, the compressive strength and splitting strength of concrete are 33.8 MPa and 3.26 MPa, respectively, the slump is 165 mm, the energy absorption rate under low-speed impact is 89.5%, the dynamic compressive strength under 0.65 Mpa impact air pressure is 58.77 mpa, and the specific energy absorption value per MPa is 13.33, which meets the requirements of shotcrete used in tunnel, roadway support and other impact loads. There is a linear relationship between the energy absorption characteristics under low-speed impact and high-speed impact. The greater the impact pressure, the larger the slope of the fitting straight line. The slope and intercept of the fitting line also show a good linear relationship with the increase of impact pressure. The conclusions can be used to predict the energy absorption characteristics under different PVC aggregate content or higher-speed impact pressure, which can provide important reference for safer, more economical, and environmental protection engineering structure design.

Investigation on the mechanical properties of press-hardened boron steel sheets using the conductive heating technique

2020 ◽  
Vol 234 (8) ◽  
pp. 1084-1098
Author(s):  
O Kocar ◽  
H Livatyalı
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Boron Steel ◽  
Fast Heating ◽  
Heating Method ◽  
Conductive Heating ◽  
Press Hardening ◽  
High Speed Impact ◽  
Significant Difference ◽  
Structural Parts

An aluminized 22MnB5 (Boron) steel sheet, used for structural parts in the automotive industry, was subjected to press-hardening followed by austenitizing, both in a conventional furnace and via the conductive (electric resistance) heating method, an innovative technique based on the Joule’s principle for fast heating of the sheet metal. Conductive heating presents a number of advantages over the in-furnace heating method. These include a more efficient use of energy, as well as the requirement of less time and space for heating, thus lowering costs. After press-hardening was performed using both methods, the microstructural and mechanical characterizations of both specimens were examined for optical microscopy, hardness, tensile strength, and high-speed impact tests. The results showed that the press-hardening process transformed the ferritic–pearlitic microstructure in the as-received state into martensite after die quenching and caused a substantial increase in hardness and strength at the expense of ductility and impact toughness. On the other hand, no significant difference was observed in either the microstructure or mechanical properties with respect to the heating method used. The results obtained in the present investigation concur with the findings of current literature.

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