Atomistic Simulation of the Explosion Welding Process

Abstract

Explosive welding (EXW) is an industrial process used to join metals together. [1,2] It is a well established method and has been in use for several decades. In the process, welding occurs in a high velocity collision between metal plates, achieved by using chemical explosives. Figure 1(a) shows the schematic arrangement of the plates in EXW. The clad layer is covered with explosive which is ignited from a point or an edge. The detonation front imposes a momentum to the clad layer which-after plastic deformation-collides with the fixed base metal. The most important process parameters are the cladding plate collision velocity v p , and the collision angle b. These are controlled by adjusting the amount and quality of the explosive and the stand-off distance y 0 . In the EXW processes used in the industry the collision velocity is typically of the order of kilometer per second. Clad layer thicknesses t can be up to centimeters and the total area of welded surface can be several square meters.The advantages of EXW include that it is a ''cold welding'' process and thus free of some of the mechanical and thermodynamic limitations of traditional welding, that it can be used to join almost any pair of metals, including those not weldable by conventional methods, and that it produces a very strong bond, that is often stronger than the weaker of the materials. The joined parts need not be specifically melted for the bonding to take place. This minimizes the formation of intermetallic-often brittle-phases near the interface. EXW is particularly suitable for structures used in harsh environ-ments: high temperatures and pressures, corrosive environments, etc.

Microstructure and mechanical properties of medium-carbon steel bonded on low-carbon steel by explosive welding

“…Saresoja, Kuronen and Nordlund in an atomistic simulation found that melting is a precondition for jet formation which in turn is a precondition for successful bonding [27], Akbari Mousavi and Al-Hassani in a numerical simulation found that the temperature rise is not high enough for melting and that jetting occurs nonetheless [20]. The results presented in this work show on the one hand a microstructure due to rapid solidification of material in a melt pocket, see Fig.…”

“…1. Detailed analytical representations of the cladding process and wave formation can be found in [4,5,16,17,22,23,25], numerical simulations of the process can be found in [10 -12, 20], and an atomistic simulation in [27].…”

Atomistic investigation on the effect of temperature on mechanical properties of diffusion-welded Aluminium-Nickel

“…The method of MD simulation is mainly built by the solution of the Newtonian equation of motion numerically which runs under a particular ensemble of atoms where can be used to investigate the material behaviors [16][17][18][19][20][21][22][23][24][25][26][27][28][29]. In the application of diffusion welding, there are several investigations using MD simulation like, Chen et al when perform an investigation of diffusion bonding between Cu-Ag [5] and Cu-Al [6] which revealing the mechanism of diffusion bonding and shed light on the importance of pressure, temperature, and surface roughness on the process.…”

Magnetic Pulse Welding: An Innovative Joining Technology for Similar and Dissimilar Metal Pairs

“…ALE method also suffers from the bad mesh quality due to the interfacial shearing and jetting. To overcome mesh issues, particle based methods were investigated among which the MD computations allow for the accurate simulation of complex interfacial morphologies but they meet a scale limitation [50][51][52]. MD method is rather appropriate for small scale, in the range of 10-100 nm unlike the SPH method that enables the computation of the interfacial jetting and wavy morphology at a large scale [42,43,53,54].…”

“…Generally, Eulerian method is used in computational fluid dynamics but can be applied to a solid to simulate a material flow, with acceptable results using a Johnson-Cook constitutive model for describing the material [44,45,56,57]. In the literature, some simulations of weakly shaped interfaces were presented [42,43,[50][51][52][53]. The method merits to be further explored to compute the full development of the wavy morphology as well as the defects' formation.…”