The mechanics of wave formation in explosive welding

1967 ◽  
Vol 296 (1445) ◽  
pp. 123-136 ◽  
Keyword(s):  
Stagnation Point ◽  
Explosive Welding ◽  
Strong Support ◽  
Welding Process ◽  
Weld Interface ◽  
Wave Formation ◽  
Flyer Plate ◽  
Low Viscosity ◽  
Observed Behaviour ◽  
Very High

Strong bonds can be produced by the explosive welding process and usually the weld interface has a characteristic wavy form. In this paper the mechanism of explosive welding is discussed, the present theories of wave formation are critically examined and a new mechanism of wave formation is proposed. According to this mechanism the materials of the impacting plates in the region of collision behave in a similar manner to liquids of low viscosity. As a result the impacting or flyer plate divides into a re-entrant jet and a salient jet. Very high pressure is produced at the stagnation point of the divided jet. The parent plate deforms under the stagnation point and consequently a hump is formed in the parent plate ahead of the point of collision. The hump builds up and eventually traps the re-entrant jet. The stagnation point then transfers to the top of the hump and then descends it and starts forming a new hump, and in this manner successive waves are formed. The proposed mechanism of wave formation seems to explain the experimentally observed behaviour reasonably well. Furthermore, experiments are reported in which one of the surfaces to be bonded was copper plated and the second surface was nickel plated and by this means the movements of the surfaces being bonded were traced. These experiments gave strong support to the proposed theory of wave formation.

Explosive Welding of SS304 and Al6061 Using Copper as Interlayer – Development of Trial Methodology and its Optimisation

2015 ◽  
Vol 830-831 ◽  
pp. 306-309
Author(s):  
Niraj Srivastava ◽  
Abhishek Upadhyay ◽  
Sandeep Kumar ◽  
Diva ◽  
Jaspreet Singh ◽  
...  
Keyword(s):  
Explosive Welding ◽  
Welding Process ◽  
Al Alloy ◽  
Flyer Plate ◽  
Trial Methodology ◽  
Al 6061 ◽  
Velocity Of Detonation ◽  
Copper Interlayer ◽  
Weldability Window ◽  
The Impact

This paper explains the technique of explosive welding for joining SS304 and Al 6061 using Copper interlayer. The joining was done in two stages. In the first stage SS304 (thickness: 20 mm) was joined to Copper (thickness: 3mm). Second stage involved joining of SS-Cu plate to Al 6061 (thickness: 8 mm).The paper presents detailed discussion on important parameters required for explosive welded process. The most important parameter is minimum and maximum flyer plate velocity required for creating the impact. Collision angle and angle of impact are also discussed. Another important parameter is the Velocity of detonation (VOD) of explosive to be used. The explosives used have VOD of the order of 2500 m/s and 1600 m/sec. Since the explosive welding process involves formation of jet between two surface, therefore surface conditions of the base and flyer plate like its flatness, roughness and cleanliness which are very critical for proper joining have been discussed in this paper. Chisel test (which is considered to be most rugged test) was conducted on the joint. The test confirmed successful joining.The paper explains how use of trimonite expands the weldability window in comparison to NGU when used for direct SS to Al alloy welding.It also compares the results obtained by use of two different powder explosives to obtain the same tri-layered plate via two different routes. The results are particularly interesting because both the explosives have substantial difference in their properties such as Velocity of Detonation, Gurney Characteristic Velocity, density and homogeneity which can be used as advantages from different angles of views.

Numerical Simulation of Underwater Explosive Welding Process

2013 ◽  
Vol 767 ◽  
pp. 120-125 ◽  
Author(s):  
Wei Sun ◽  
Xiao Jie Li ◽  
Kazuyuki Hokamoto
Keyword(s):  
Numerical Simulation ◽  
Explosive Welding ◽  
Welding Process ◽  
High Hardness ◽  
Acceleration Process ◽  
Flyer Plate ◽  
Underwater Shock Wave ◽  
Experimental Parameters ◽  
Wave Morphology ◽  
Underwater Shock

Recently, underwater explosive welding shows its advantage in some difficult-to-weld combinations such as material with thin thickness, high hardness, and fragile quality. The pattern of the typical wave morphology in the interface of the welding specimen indicates the suitability of the selected experimental parameters and sound strength of the laminates. For the existence of the water, traditional Gurney formula and Aziz formula can not directly be used to evaluate the velocity and acceleration process of the flyer plate. Numerical simulation is necessary and irreplaceable for existing knowledge. Underwater explosive welding process was numerically simulated by ANSYS/LS-DYNA to explore the underwater shock wave and deformation process of the flyer plate. Velocity and pressure distribution of welding plates were obtained. The velocity of the flyer plate could satisfy the minimum velocity in explosive welding. It was found that water prevented the gross distortion and ensured the integrity of the composite laminate. Welding rate was increased by expanding the size of the explosive.

Sixth Paper: Explosive Welding and Cladding: An Introductory Survey and Preliminary Results

1964 ◽  
Vol 179 (1) ◽  
pp. 264-305 ◽  
Author(s):  
A. S. Bahrain ◽  
B. Grassland
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Explosive Welding ◽  
Weld Interface ◽  
Impact Angle ◽  
Flyer Plate ◽  
Pressure Welding ◽  
Explosive Cladding ◽  
Related Subject ◽  
Bend Tests

This paper reviews the published literature on the explosive welding of metals and the related subject of pressure welding. The mechanism of explosive welding is closely associated with that of shaped charges with metal linings, so a brief résumé of the theory of such charges is given. It is also noted that fluid waves are sometimes generated at the weld interface in explosively welded joints, and the mechanism of their generation is discussed. Experiments are reported on the explosive cladding of mild steel with stainless steel, 70/30 brass, and high-conductivity copper. These have been aimed at establishing the effect of impact angle, weight of charge, and the thickness of the flyer plate on the form of the weld achieved. The mechanical strength of the welded joints has been investigated by shear, tension, and bend tests, and the variation of hardness across the weld interface has also been examined. Results of these various tests are presented and discussed. It is concluded that explosively cladded material has some advantages over conventionally pressure cladded material. In particular it is probable that the strength of the welded interface is much stronger. With large charges and small angles of impact it is possible for the parent plate to suffer from shock damage which can be clearly seen under a microscope, but it is not known if this is harmful to the mechanical properties. Hardness is increased each side of the interface but a reduced value is measured close to the interface.

scholarly journals Microstructure and Mechanical Properties of Dissimilar Friction Welding Ti-6Al-4V Alloy to Nitinol

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 109
Author(s):  
Ateekh Ur Rehman ◽  
Nagumothu Kishore Babu ◽  
Mahesh Kumar Talari ◽  
Yusuf Siraj Usmani ◽  
Hisham Al-Khalefah
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flow Stress ◽  
Intermetallic Compound ◽  
Ultimate Tensile Strength ◽  
Friction Welding ◽  
Welding Process ◽  
Weld Interface ◽  
Dissimilar Joints ◽  
Dissimilar Alloys

In the present study, a friction welding process was adopted to join dissimilar alloys of Ti-Al-4V to Nitinol. The effect of friction welding on the evolution of welded macro and microstructures and their hardnesses and tensile properties were studied and discussed in detail. The macrostructure of Ti-6Al-4V and Nitinol dissimilar joints revealed flash formation on the Ti-6Al-4V side due to a reduction in flow stress at high temperatures during friction welding. The optical microstructures revealed fine grains near the Ti-6Al-4V interface due to dynamic recrystallization and strain hardening effects. In contrast, the area nearer to the nitinol interface did not show any grain refinement. This study reveals that the formation of an intermetallic compound (Ti2Ni) at the weld interface resulted in poor ultimate tensile strength (UTS) and elongation values. All tensile specimens failed at the weld interface due to the formation of intermetallic compounds.

METALLURGICAL AND CORROSION CHARACTERIZATION OF POST WELD HEAT TREATED DUPLEX STAINLESS STEEL (UNS S31803) JOINTS BY FRICTION WELDING PROCESS

2016 ◽  
Vol 23 (03) ◽  
pp. 1650013 ◽  
Author(s):  
MOHAMMED ASIF M. ◽  
KULKARNI ANUP SHRIKRISHNA ◽  
P. SATHIYA
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Friction Welding ◽  
Volume Fraction ◽  
Welding Process ◽  
Equilibrium Temperature ◽  
Weld Interface ◽  
Heat Treated ◽  
Weld Heat

The present study focuses on the metallurgical and corrosion characterization of post weld heat treated duplex stainless steel joints. After friction welding, it was confirmed that there is an increase in ferrite content at weld interface due to dynamic recrystallization. This caused the weldments prone to pitting corrosion attack. Hence the post weld heat treatments were performed at three temperatures 1080[Formula: see text]C, 1150[Formula: see text]C and 1200[Formula: see text]C with 15[Formula: see text]min of aging time. This was followed by water and oil quenching. The volume fraction of ferrite to austenite ratio was balanced and highest pit nucleation resistance were achieved after PWHT at 1080[Formula: see text]C followed by water quench and at 1150[Formula: see text]C followed by oil quench. This had happened exactly at parameter set containing heating pressure (HP):40 heating time (HT):4 upsetting pressure (UP):80 upsetting time (UP):2 (experiment no. 5). Dual phase presence and absence of precipitates were conformed through TEM which follow Kurdjumov–Sachs relationship. PREN of ferrite was decreasing with increase in temperature and that of austenite increased. The equilibrium temperature for water quenching was around 1100[Formula: see text]C and that for oil quenching was around 1140[Formula: see text]C. The pit depths were found to be in the range of 100[Formula: see text]nm and width of 1.5–2[Formula: see text][Formula: see text]m.

Numerical Simulation on Explosive Welding Process Using Reflected Underwater Shock Wave

2007 ◽  
Vol 566 ◽  
pp. 309-314
Author(s):  
Kazumasa Shiramoto ◽  
Masahiro Fujita ◽  
Yasuhiro Ujimoto ◽  
Hirofumi Iyama ◽  
Shigeru Itoh
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Explosive Welding ◽  
Welding Process ◽  
Underwater Shock Wave ◽  
Underwater Shock ◽  
Effective Use

The paper describes a numerically simulated result for the explosive welding using reflected underwater shock wave. Through the numerical simulation, the effective use of reflected underwater shock wave was clearly suggested and the method to improve the assembly was demonstrated.

Microstructure and mechanical properties of ADC12/6063-T6 aluminum alloy butt joint achieved by metal inert gas groove welding

2018 ◽  
Vol 233 (10) ◽  
pp. 2120-2124
Author(s):  
Ye Wang ◽  
Mi Zhao ◽  
Hongyu Xu ◽  
Maoliang Hu ◽  
Zesheng Ji
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Welding Process ◽  
Weld Interface ◽  
Butt Joint ◽  
Inert Gas ◽  
Butt Joints ◽  
Arc Welding Process ◽  
The Impact ◽  
Silicon Particles

Metal inert gas arc welding process was implemented to join 6063T6 wrought alloy and ADC12 die-casting alloy using ER4047 filler metal. The microstructure of the weld seam and weld interface was investigated. The bonding strength of the butt joints was tested by Charpy U-notch impact test and tensile test. The results showed that a sound welding butt joint with finely silicon particles and excellent mechanical properties was formed, and the size of the silicon particles was nearly 2 μm. Compared with 6063T6 wrought alloy, the impact absorbing energies and the tensile strengths of the butt joint were higher and reached 1.173 kJ/cm2 and 205 MPa, respectively, and the fractures of all tensile specimens occur at the 6063T6 aluminum.

scholarly journals Contributions Regarding the Use of Mechanical Vibrations in Order to Improve the Properties of Steels and Welded Joints Used in Metal Constructions

2020 ◽  
Vol 21 (2) ◽  
pp. 67-71
Author(s):  
Gheorghe Novac ◽  
Bogdan Novac
Keyword(s):  
Welded Joints ◽  
Arc Welding ◽  
Significant Contribution ◽  
Welding Process ◽  
Internal Stresses ◽  
Welding Equipment ◽  
Welding Technology ◽  
Submerged Arc ◽  
Very High

The paper presents aspects regarding the influence of vibrations on the mechanical properties of welded joints, made with basic materials of Spanish and Romanian origin. In this research is presented the practical way to make the necessary assemblies for the proposed tests. The tests show that vibrations have a significant contribution to the quality of welded joints. This is explained by the appearance of several crystallization centres which makes the structure finer. By using vibrations, the atoms are rearranged in the structure, ensuring a proper de-tensioning. The stresses induced in welded metals are significantly reduced by the use of vibration during welding process. The addition materials have a significant contribution to the emergence of stresses in welded joints as well. These stresses can contribute to the appearance of microstructural constituents with significant hardness. The welding equipment and technologies used also have a significant contribution to the emergence of the remaining stresses. For example, the submerged arc welding technology (SAF) can introduce very high internal stresses. By using vibrations during the welding process, it is achieved a fine structure and a significant reduction of remaining stresses in the welded joints.

Mechanism of wave formation at the interface in explosive welding

1989 ◽  
Vol 5 (2) ◽  
pp. 97-108 ◽  
Author(s):  
Cheng Chemin ◽  
Tan Qingming
Keyword(s):  
Explosive Welding ◽  
Wave Formation
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