A study of the peen forming of thin stainless steel metal foils (50 $\mathsf{\mu }\mathrm{m}$ thick) using a solid-state ps-pulsed laser, emitting at a wavelength of $1064 \mathrm{nm}$ was conducted. The pitch distance between consecutive laser pulses was kept constant by tuning the laser repetition rate from 0.4 to 10 $\mathrm{kHz}$, and subsequently the scanning speed. The induced bending angle and the radius of curvature were used to measure the effect of the treatment. Their dependence on the pulse energy, the treated area, the distance between lines, and the laser repetition rate was studied. High repetition rates do not allow the sample to cool down, affecting the bending to the point of being negligible. An FEM simulation and experiments were carried out to prove that the increase in temperature due to high repetition rate can relax the stresses induced by laser peen treatment, thus preventing bending in the sample.

Laser-induced forward transfer for high-viscosity—of Pa·s—pastes differ from standard LIFT processes in its dynamics. In most techniques, the transference after setting a great gap does not modify the shape acquired by the fluid, so it stretches until it breaks into droplets. In contrast, there is no transferred material when the gap is bigger than three times the paste thickness in LIFT for high-viscosity pastes, and only a spray is observed on the acceptor using this configuration. In this work, the dynamics of the paste have been studied using a finite-element model in COMSOL Multiphysics, and the behavior of the paste varying the gap between the donor and the acceptor substrates has also been modeled. The paste bursts for great gaps, but it is confined when the acceptor is placed close enough. The obtained simulations have been compared with a previous work, in which the paste structures were photographed. The analysis of the simulations in terms of speed allows for predicting the burst of the paste—spray regime—and the construction of a printability map regarding the gap between the substrates.

The Ni-hard alloys white-cast irons are generally used for high wear work. Among them, those with better impact resistance because of its low carbon content compared to the rest of the family, are studied in this paper. One experimental technique of characterizing the metallic materials is the microstructural study. Several metallographic attacks intended to reveal qualitatively each microconstituent that forms the alloy, as well as the segregation and solidification structure of casting, are studied in this article. The use of color metallography is fundamental in this case to distinguish clearly the microconstituents. The main objective of this paper is to propose a series of attacks that identify each one of the microconstituents present in the alloy that has not been reported up to date.

Laser shock processing (LSP) is a surface treatment technique used to enhance mechanical properties such as hardness, corrosion resistance, and wear resistance. This study investigates the effects of LSP on a 6061-T6 aluminium alloy using four treatment conditions: nanosecond (ns-LSP), picosecond (ps-LSP), and a combination of nanosecond–picosecond (nsps-LSP) and picosecond–nanosecond (psns-LSP) pulses. Two laser systems were employed: a Q-switched Nd:YAG laser (850 mJ/pulse, 6 ns, 1064 nm, 10 Hz), and an Ekspla Atlantic 355-60 laser (0.110 mJ/pulse, 13 ps, 1064 nm, 1 kHz). All treatments induced compressive residual stresses up to 1 mm in depth. Additionally, improvements in microhardness were observed, particularly at deeper layers in the combined nsps-LSP treatment. Surface roughness was measured and compared. Among all configurations, the nsps-LSP treatment produced the highest compressive residual stresses (−428 MPa) and greater microhardness at depth. These results suggest that the combined nsps-LSP treatment represents a promising approach to enhance the mechanical performance of metallic components.

Laser-induced forward transfer (LIFT) is a fast, clean, non-contact metallization technique that allows the deposition of small volumes (down to picoliters) of a wide range of materials in a very precise and controlled way. In this work, we show a complete description of the metallization by LIFT using pulsed laser sources and a commercial silver-based paste. We include a description of the transference process and discuss the influence of the paste viscosity and the acceptor substrate roughness. To avoid the use of a standard paste-curing process in a furnace, a second laser process is used to cure the silver paste in a selective way, preventing any thermal damage in the materials below the paste or in other parts of the device. In summary, we show that the use of a LIFT technique allows the metallization of wide areas with high aspect ratio lines, that can be cured selectively, and present very good mechanical properties, being suitable for its use in flexible electronics applications.