0000000001316428
AUTHOR
Rija Nirina Raoelison
On the complete interface development of Al/Cu magnetic pulse welding via experimental characterizations and multiphysics numerical simulations
Abstract A complex Al/Cu magnetic pulse welding interface is systematically investigated using experimental characterizations and numerical simulations. A Coupled electromagnetic-mechanical simulation is proposed to compute the impact velocity and impact angle along the entire interface. This model allows to further understand the formation mechanism of various interface characteristics during MPW. The results revealed that the impact velocity gradually decreases in conjunction with the gradual increase of the impact angle. These simulations elucidate the experimentally observed successive interface morphologies, i.e., the unwelded zone, vortex zone, intermediate (IM) layers and wavy interf…
Inverse prediction of local interface temperature during electromagnetic pulse welding via precipitate kinetics
Abstract Interface temperature of electromagnetic pulse welding is difficult to measure by insitu methods. Here, the local temperature rise is investigated using the kinetics of precipitates and dispersoids (transformation or dissolution) at the interface zone (IZ) and affected zone (AZ) of three welds. This fine scale analysis allows estimating of local temperature range for AZ that reaches between 250 and 360 °C on both sides of narrow IZ, while the IZ itself experiences between 360 and 500 °C or even beyond 500 °C. The interface temperature increases with the increasing impact intensity. The current work estimated thermal field based on the precipitate transformations, which occur during…
Analytical description of solid particles kinematics due to a fluid flow and application to the depiction of characteristic kinematics in cold spraying
Abstract In several multiphase flow applications such as fluidization, thermal spraying, atomization manufacturing and so on, the Newton's law is widely enacted to formulate the particle/fluid kinematic interaction and then to compute particles kinematics. This paper provides analytical solutions of the Newton's law in its time-dependent formulation or simplified formulation, the latter being a reduction of the time dependent problem into a spatial description of the particle motion. It was found that the velocity solution is strictly similar in both cases so that the simplified formulation is viable. The W_ 1 branch of the Lambert's function yields the analytical particle residence time an…
Interface evolution during magnetic pulse welding under extremely high strain rate collision: mechanisms, thermomechanical kinetics and consequences
Abstract Magnetic pulse welding enables to produce perplexing interfacial morphologies due to the complex material response during the high strain rate collision. Thus, a thermomechanical model is used in this study to investigate the formation mechanism of the wake, vortex, swirling and mesoscale cavities with the increase of the impact intensity at the interface. The formation of these interfacial features are difficult to characterize by insitu methods, thus the origin of phenomena still remain a subject of open discussion. Our studies identify the governing mechanisms and the associated thermomechanical kinetics, which are responsible for the formation mechanism of interfacial features.…
An anomalous wave formation at the Al/Cu interface during magnetic pulse welding
This paper reports an anomalous wave formation at an Al/Cu bimetallic interface produced by magnetic pulse welding. The mechanism of the anomalous wave formation is investigated using both metallurgical characterization and the interface kinematics. It reveals that the anomalous wave is formed with the combination of the intermediate zone and the interdiffusion zone with a thickness of 70 nm, wherein the intermediate zone is caused by the local melting due to the high shear instability, and the interdiffusion zone is formed below the melting point of aluminum combined with ultrahigh heating and cooling rates of about 10^13 °C s^−1. A multiphysics simulation of impact welding has been perfor…
Turbulences of the supersonic gas flow during cold spraying and their negative effects: A DNS CFD analysis coupled with experimental observation and laser impulse high-speed shadowgraphs of the particles in-flight flow
Abstract This paper investigates the phenomenological flow during cold spraying through DNS CFD analysis and experimental observations. The transient DNS computation shows that the gas flow begins to be instable inside the nozzle and generates self-sustained intermittent swirls across the nozzle exit due the shearing behavior of the flow. There is alternate swirling within the separated sheared layers on top and then on bottom of the jet, at sporadic time intervals. The swirls are not strictly periodic in nature, but they recur with an irregular frequency. The temperature field exhibits analogous variation and the thermal turbulence produces a heating confinement within the end zone of the …
Cold gas dynamic spray technology: A comprehensive review of processing conditions for various technological developments till to date
Abstract Today, cold gas dynamic spray (CGDS) technology has thrived with considerable capabilities for manufacturing various technological depositions. The deposition conditions have been developed through many years and that have led to produce ample experimental data which is available in the literature. But, recent research and development activities also reveal innovative findings regarding various deposition conditions. This paper contains a review of experimental deposition procedures for the cold spray additive manufacturing. Details of processing conditions are reported and classified into various categories of baseline working conditions, specific processing including deposition o…
In-flight temperature of solid micrometric powders during cold spray additive manufacturing
Abstract During cold dynamic gas spray additive manufacturing, the thermal field within particles is generally simplified by a state of an instantaneous uniform distribution over the particle's media at any position inside and outside the De-Laval nozzle. This paper addresses critical discussions using analytical and computational analysis of the transient heat transfer within the solid particles due to the convective exchange with the flowing gas. An analytical criterion depicts conditions of instantaneous uniform temperature over the range of typical cold spray data including various particle thermal conductivity, particle size range, dragging velocities, gas nature and gas setting condit…
A new nature of microporous architecture with hierarchical porosity and membrane template via high strain rate collision
Abstract This paper presents the formation of an unusual porous structure at Al/Al interface joined by magnetic pulse welding. The porous structure consists of a hierarchical microporous architecture with pore size of less than 2 µm that represents more than 80% over the whole area, in which 38% of them are sub-micron size pores. It also exhibits ultra-thin wall, sufficiently thin enough to behave as an electron-transparent material with a wall thickness of 50 nm. The formation of this porous structure is attributed to a cavitation process of a molten material in three stages including, (1) nucleation, (2) growth and coalescence and (3) solidification. Further analysis of this cavitation pr…
Flow phenomenon of micron-sized particles during cold spray additive manufacturing: High-speed optic observation and characterization
Abstract A high-speed laser shadowgraph observation of the particles flow during cold spraying enables a good phenomenological characterization. The particles in-flight behaviour develops a kinematics with two regimes regardless the powder nature. When leaving the nozzle, the particles form a regime of uniform jet over a certain distance along the flow direction, and then a regime of sparse jet while particles deviate in the radial direction. This dispersion increases away from the nozzle exit and exhibits thereby an event of oblique collision during an additive route process. Under such conditions, kinematic deficiency prevails since oblique collision has shown to alter the deposition effi…
Cold gas dynamic spray additive manufacturing today: Deposit possibilities, technological solutions and viable applications
This paper reports the current potentials of cold gas dynamic spraying (CGDS). CGDS has been significantly developed to produce several functional solutions categorized as follows: deposits with a single powder nature, composites-based deposits, nanotechnological deposits and hybrid coating/substrate assemblies. CGDS process has improved in proficiency and is still gaining attention from scientists and industry. Covering a wide range of materials, both standard and advanced, this additive manufacturing process offers substantial applications for surface functionalization, structural or dimensional restoration, bulk production providing specific material properties, and art/decoration. Progr…
Assessing the influence of fieldshaper material on magnetic pulse welded interface of Al/Cu joints
Abstract Fieldshaper (FS) is a widely used component in magnetic pulse forming and welding to improve the efficiency of the process. It enables to increase the magnetic pressure experienced by the workpieces during forming and welding. Recent developments in this subject focuses to increase the life time of the fieldshaper and to improve the efficiency by introducing shape optimized designs. In this study, we compare the efficiency of four fieldshapers made of Cuprofor, Siclanic, CuBe2 and Steel. The main focus is given to the effect of material properties while the same geometry was considered for those four fieldshapers. The same welding conditions (discharge voltage of 6kV and air gap of…
Coeval Cold Spray Additive Manufacturing Variances and Innovative Contributions
Tremendous attention has been given to the cold spray process, even more today with the emergence of additive manufacturing, worldwide. Several inventions related to the cold spray technology have been patented for over a century and mostly since a couple of decades. But the cold spray technology knows a period of great innovations due to recent and current substantial explorations. Various technological solutions have been developed. The technical dimension, and particularly in terms of manufacturing method, has also always been a major genesis of progresses and novelties. This chapter is a technological survey of the cold spray additive manufacturing and reports variant methods and innova…
Data for: A new nature of microporous architecture with hierarchical porosity and membrane template via high strain rate collision
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