Ultrasonic technology is widely applied in the engineering ceramic polishing processes without the limitation of material properties and ideally integrated into computer numerical control system. Ultrasonic-induced cavitation and mechanical vibration effect could accelerate the motion of solid abrasives. The individual behaviors of microjet/shockwave of ultrasonic cavitation in gases and liquids, and micro-abrasives with simple harmonic vibrations in solids and liquids has been extensively studied. To conduct a systematic and integrated study of abrasives behavior in the polishing contact region involving abrasive, surround-workpiece wall, ultrasonic physical vibration, and ultrasonic cavitation impact, a novel model integrating the free abrasive motion velocity and fixed abrasive indentation depth under multi-scale contact was proposed according to Hertzian contact theory, Greenwood-Williamson model, indentation deformation theory, the basic equations of cavitation bubble dynamics, cavitation impact control equations, and Newton's law of motion equation. The effects of ultrasonic amplitude, ultrasonic frequency, preloading force and particle size on the proposed model were investigated by theoretical analysis and numerical simulations. Ultrasonic physical vibration mainly influences the dynamic gap and further influence the number of different abrasives. Furthermore, the indentation depth of fixed abrasive depends mainly on the abrasive geometry. As the contact gap and abrasive size decrease, the indentation depth gradually decreases. Under the synergistic effect of cavitation-induced shock wave and microjet, the velocity of free abrasive in this paper is generally 0-150 m/s, and the kinetic energy of free abrasive increases roughly linearly with increasing frequency and approximately as a quadratic function with increasing particle size. Increasing the preloading force leads to a reduction in the abrasive kinetic energy. Besides, the kinetic energy induced by the shock wave has a cliff-like increment at an amplitude of 0.7-0.8 μm. It is revealed that the abrasive kinetic energy is suppressed by the cavitation bubble expansion and collapse at smaller ultrasonic pressure amplitude and surround-wall distance. This research provides a theoretical reference for the modeling of potential defects and material removal on the workpiece surface caused by abrasive motion during polishing, and reduces the trial cost for parameter optimization in actual polishing processing.

Stainless steel 316L is an austenitic alloy that is widely used in varying industries due to its outstanding corrosion resistance, high strength, and ductility properties. However, the wear and friction resistance properties are low. Laser surface texturing can improve the wear and friction resistance of the material via the functionalisation of the surface. The laser surface texturing efficiency and the texture quality are defined by the material’s surface properties and laser parameters. The surface roughness is an important material property having an effect on laser surface texturing. This paper reports on a study of the material’s surface roughness influence on the texturing of 316L stainless steel with 1064 nm nanosecond pulsed laser. Single pulse shots were employed to avoid the topographic influence of the previous laser shots. The surface shape and the topography of the textures were assessed using optical microscopy and profilometry. It was observed that the textures produced were dimples of U-type and sombrero-like type geometries depending on surface roughness and pulse energy. The overall quality of the texture shape was better for smoother surfaces. The energy fluence necessary to generate textures is lower on surfaces of lower roughness than surfaces with high roughness. The surface at 24 nm of average roughness is the best surface for creating deep textures. The ablation mechanisms associated with high pulse energy, including plasma shielding, are produced at lower pulse energies for the 100 nm roughness, compared with other roughness samples.

Commercially pure aluminium is employed in several industrial applications. On some applications, the surface of this material needs to be functionalised. Laser surface texturing is a powerful tool to functionalise aluminium and aluminium alloy surfaces. However, the corrosion resistance of the laser textured aluminium alloy can be modified, and this has rarely been investigated in the literature. Consequently, the corrosion resistance of the laser textured commercially pure aluminium in saltwater was evaluated using several electrochemical techniques: asymmetric electrochemical noise, potentiodynamic polarisation curve and electrochemical impedance spectroscopy. Although the non-laser surface textured samples possessed higher kinetic corrosion resistance in the first hours of immersion, the corrosion mechanism (process group of the corrosion) was found to be more unstable than the laser textured specimens. The oxidised layer of the textured samples was also nobler than the native passive film.

Controlling in situ nanoparticle formation and growth in Cu complex inks during decomposition and sintering process by modifying ink chemistry (complexing molar ratio, organic solvent) and influencing sintering parameters (temperature, ramp rate).