Hardfacing steel with nanostructured coatings of Stellite-6 by supersonic laser deposition

Abstract

The ability to manufacture coatings is critical to engineering design. Many components require the application of additional layers to enhance mechanical properties and protect against hostile environments. Supersonic laser deposition (SLD) is a novel coating method based on cold spray (CS) principles. In this technique, the deposition velocities can be significantly lower than those required for effective bonding in CS applications. The addition of laser heat energy permits a change in the thermodynamic experience of impacting particles, thereby offering a greater opportunity for efficient bonding at lower velocities as compared with the CS process. The work reported in this paper demonstrates the ability of the SLD process to deliver hardfacing materials to engineering surfaces. Stellite-6 has been deposited on low-carbon steel tubes over a range of process parameters to establish the appropriate target power and traverse speeds for the coating formation. The coating properties and parameters were examined to determine the primary characteristics and grain structure size. Their morphology and performance were studied through optical microscopy, scanning electron microscope (SEM), X-ray diffraction, hardness measurements and wear testing. The results have shown that SLD is capable of depositing layers of Stellite-6, with properties that are superior to those of their conventionally manufactured counterparts.

Characteristics and performance of hard Ni60 alloy coating produced with supersonic laser deposition technique

“…In the SLD process, laser is used to heat the deposition zone in order to soften both substrate and powder particles thus allowing the formation of a coating at a much reduced impact velocity [29,30]. Luo et al [31,32] and Lupoi et al [33] studied the wear resistance of Stellite 6 coatings deposited by LC and SLD, the results showed that the properties of the SLD layers of Stellite 6 were superior to those of their conventionally manufactured counterparts. Although SLD technique has been proposed for depositing hard materials, the SLD process has not been well studied, in particular, the performance and characteristics of the coatings of hard and low melting point Ni-based alloys.…”

Simultaneous Femtosecond Laser Doping and Surface Texturing for Implanting Applications

“…At lower laser energy density of F = 0.07 J cm −2 , subwavelength nanofringes, which are always called laser-induced periodic surface structure (LIPSS), can be fabricated on the surface of sample. The mean period of nanofringes is about 530 nm which is smaller than laser wavelength (800 nm), [ 35 ] as shown in Figure 2 a. For linearly polarized incident laser light, the possible physical mechanisms of the nanofringes formation has been given as due to the interference between the incident laser light wave and the excited surface plasmon wave.…”

Performance characterization of Ni60-WC coating on steel processed with supersonic laser deposition

“…Matthew et al [8,9] successfully combined laser cladding with cold spraying together to prepare high-density coatings consisting of Ti and Ti alloy, and used cold N 2 as a carrier gas to reduce the cost of cold spraying. The supersonic laser deposition (SLD) method offers many advantages by combining laser with cold spraying, in particular, the use of a laser to control the deposition temperature, which allows hard materials, such as Stellite 6 and carbide [10,11], to be deposited while maintains the key advantages offered by solid-state cold spraying and replaces high cost helium with nitrogen. Moreover, the high-speed impact of particles on the substrate produces severe plastic deformation, resulting in a good bonding of the coating and the substrate.…”