Laser Shock Flier Impact Simulation of Particle-Substrate Interactions in Cold Spray

Abstract

Coating-substrate adhesion in cold spray is a paramount property, the mechanisms of which are not yet well elucidated. To go into these mechanisms, due to the intrinsic characteristics of the cold spray process (particle low-temperature and high velocity) direct observation and control of inflight particles and related phenomena cannot be done easily. For this reason, an experimental simulation of the particle-substrate reactions at the particle impingement was developed. This simulation is based on original flier impact experiments from laser shock acceleration. Relevant interaction phenomena were featured and studied as a function of shearing, plastic deformation, phase transformation primarily. These phenomena were shown to be similar to those involved in cold spray. This was ascertained by the study of the Cu-Al metallurgically reactive system using SEM, TEM, EPMA, and energy balance and diffusion calculations. This simulation could also be used to feed finite element modeling of cold spray and laser shock flier impact.

Cold spraying – A materials perspective

“…Similar microstructural features have also been observed in magnetic pulse welding [66]. analogy between bonding characteristics in explosive welding and CS has also been considered as a basis to devise laser shock experiments [67] as a micron-scale physical model of particle impact in CS. These experiments resemble explosive welding geometrically, but relate to particle impact in terms of system size.…”

The Influence of the Substrate on the Deposition of Cold-Sprayed Titanium: An Experimental and Numerical Study

“…Experiments (Ref 12) and numerical simulations ( Ref 13) indicate that, under certain conditions during the creation of cold-sprayed coating, melting cannot occur at the particle-substrate interface. On the other hand, other experimental studies show evidence of local fusion at the substrate-particle interface (Ref 11,14) as well as interlamellar local melting ( Ref 15). These experiments show an increase of coating adhesion due to the presence of molten phases ( Ref 12,14).…”

“…On the other hand, other experimental studies show evidence of local fusion at the substrate-particle interface (Ref 11,14) as well as interlamellar local melting ( Ref 15). These experiments show an increase of coating adhesion due to the presence of molten phases ( Ref 12,14). The presence or the absence of local melting seems to depend on the materials and experimental conditions.…”

Observation of High Resolution Microstructures in Thermal Sprayed Coatings and Single Deposited Splats Using Ion Beam Milling

“…[17][18][19][20] Many researchers hence have made TEM samples by the FIB method from micron-sized powders or small splats or thick coating layers at a desired location. 1,[21][22][23][24][25][26][27][28][29] Because the FIB is an imaging tool in its own right as well as the milling and thinning capability in sample preparation, 30) during the FIB fabrication, one can check the milling state and get images of the sample.…”

“…16) Therefore, when observing a thermal-sprayed splat from the surface to the interface of splat/substrate with TEM, it is quite difficult to obtain high resolution atomic structure images near the interface of splat/substrate because the region is too thick to derive the atomic structure. 1,[21][22][23][24] For the high resolution images, several researchers prepared firstly the cross section of a single splat by a conventional polishing method using silicon carbide (SiC) papers or the FIB method and then, from the cross section, several TEM samples were made respectively at desired locations within the single splat. [27][28][29] Once a TEM sample was made and observed, it is generally impossible to prepare much thinner sample at the desired position.…”