Applied Physics A

http://link.springer.com/journal/339

List of Papers (Total 316)

Damage range in swift Xe26+ ion-irradiated polycrystalline iron and silver studied by positron annihilation technique, long-range effect

Investigations of defects and their spatial distribution in iron and silver irradiated with swift Xe26+ ions of different energies: 18.5, 45.5, 122.5 and 167 MeV have been performed using conventional positron lifetime spectroscopy. In the implanted layer, in which the ions are stopped, dislocations and clusters of vacancies were found in iron and only dislocations in sliver. In...

X-ray emission as a potential hazard during ultrashort pulse laser material processing

In laser machining with ultrashort laser pulses unwanted X-ray radiation in the keV range can be generated when a critical laser intensity is exceeded. Even if the emitted X-ray dose per pulse is low, high laser repetition rates can lead to an accumulation of X-ray doses beyond exposure safety limits. For 925 fs pulse duration at a center wavelength of 1030 nm, the X-ray emission...

Femtosecond laser-induced herringbone patterns

Femtosecond laser-induced herringbone patterns are formed on copper (Cu). These novel periodic structures are created following s-polarized, large incident angle, femtosecond laser pulses. Forming as slanted and axially symmetric laser-induced periodic surface structures along the side walls of ablated channels, the result is a series of v-shaped structures that resemble a...

Three-dimensional direct laser written graphitic electrical contacts to randomly distributed components

The development of cost-effective electrical packaging for randomly distributed micro/nano-scale devices is a widely recognized challenge for fabrication technologies. Three-dimensional direct laser writing (DLW) has been proposed as a solution to this challenge, and has enabled the creation of rapid and low resistance graphitic wires within commercial polyimide substrates. In...

Hyperspectral imaging and multivariate analysis in the dried blood spots investigations

The aim of this study was to apply a new methodology using the combination of the hyperspectral imaging and the dry blood spot (DBS) collecting. Application of the hyperspectral imaging is fast and non-destructive. DBS method offers the advantage also on the micro-invasive blood collecting and low volume of required sample. During experimental step, the reflected light was...

In-volume structuring of silicon using picosecond laser pulses

We have demonstrated for the first time the permanent local modification of the bulk of silicon by repeated illumination with infrared (1.55 μm) picosecond pulses. Furthermore, we evaluated the characteristics of inscribing permanent modifications in the bulk material for different pulse durations from 0.8 to 10 ps in terms of their reproducibility and controllability of their...

Fluorescent carbon and graphene oxide nanoparticles synthesized by the laser ablation in liquid

The results of synthesis of the fluorescent carbon dots (CDots) from graphite target and reduced graphene oxide (rGO) nanoparticles performed by the nanosecond laser ablation in polyethylene glycol 200 (PEG200) are shown. Two-step laser irradiation (first graphite target, next achieved suspension) revealed a very effective production of CDots. However, the ablation in PEG...

The structure and mechanical properties of AlMg5Si2Mn alloy after surface alloying by the use of fiber laser

Laser surface treatment is successfully applied to increase hardness as well as corrosion and wear resistance in light alloys such as aluminum or magnesium. The laser surface remelting also can be used to repair superficial cracks, voids or porosity caused by the mechanical impact, metallurgical process as well as the corrosive environment on the surface of the aluminum alloy...

Thermomechanical modelling of laser surface glazing for H13 tool steel

A two-dimensional thermomechanical finite element (FE) model of laser surface glazing (LSG) has been developed for H13 tool steel. The direct coupling technique of ANSYS 17.2 (APDL) has been utilised to solve the transient thermomechanical process. A H13 tool steel cylindrical cross-section has been modelled for laser power 200 W and 300 W at constant 0.2 mm beam width and 0.15...

An analytical model to predict and minimize the residual stress of laser cladding process

Laser cladding is one of the advanced thermal techniques used to repair or modify the surface properties of high-value components such as tools, military and aerospace parts. Unfortunately, tensile residual stresses are generated in the thermally treated area of this process. This work focuses on to investigate the key factors for the formation of tensile residual stress and how...

Mechanisms of damage formation in glass in the process of femtosecond laser drilling

The development of femtosecond lasers has renovated micromachining technology, enabling the microdrilling of transparent materials at high speed. Although effective, this technique is still imperfect because irregular microscopic damage occurs during processing. Several factors in the formation of damage induced by a single laser pulse have been suggested; however, the entire...

Tailored laser beam shaping for efficient and accurate microstructuring

Large-area processing with high material removal rates by ultrashort pulsed (USP) lasers is coming into focus by the development of high-power USP laser systems. However, currently the bottleneck for high-rate production is given by slow and inefficient beam manipulation. On the one hand, slow beam deflection with regard to high pulse repetition rates leads to heat accumulation...

Nanostructures on fused silica surfaces produced by ion beam sputtering with Al co-deposition

The ion beam sputtering (IBS) of smooth mono-elemental Si with impurity co-deposition is extended to a pre-rippled binary compound surface of fused silica (SiO2). The dependence of the rms roughness and the deposited amount of Al on the distance from the Al source under Ar+ IBS with Al co-deposition was investigated on smooth SiO2, pre-rippled SiO2, and smooth Si surfaces, using...

Liquid phase separation and rapid dendritic growth of undercooled ternary Fe60Co20Cu20 alloy

Liquid ternary Fe60Co20Cu20 alloy was undercooled by up to 357 K (0.21 T L) with glass fluxing method and its rapidly solidified microstructures were investigated by EDS and EBSD technologies. The ternary Fe60Co20Cu20 alloy rapidly solidifies with rapid dendritic growth of the primary γ-Fe phase within 37–243 K undercooling range. When the alloy melt is undercooled to 243 K, an...

Pulse energy packing effects on material transport during laser processing of \(<1|1|1>\) silicon

The effects of energy pulse packing on material transport during single-pulse laser processing of \(<1|1|1>\) silicon is studied using temporarily shaped pulses with durations from 50 to 150 ns. Six regimes of material transport were identified and disambiguated through energy packing considerations over a range of pulse durations. Energy packing has been shown to shift the...

Selective laser melting of hypereutectic Al-Si40-powder using ultra-short laser pulses

We investigate the use of ultra-short laser pulses for the selective melting of Al-Si40-powder to fabricate complex light-weight structures with wall sizes below \(100\,\upmu \text {m}\) combined with higher tensile strength and lower thermal expansion coefficient in comparison to standard Al–Si alloys. During the cooling process using conventional techniques, large primary...

Investigation of the wavelength dependence of laser stratigraphy on Cu and Ni coatings using LIBS compared to a pure thermal ablation model

In this study, galvanic coatings of Cu and Ni, typically applied in industrial standard routines, were investigated. Ablation experiments were carried out using the first two harmonic wavelengths of a pulsed Nd:YAG laser and the resulting plasma spectra were analysed using a linear Pearson correlation method. For both wavelengths the absorption/ablation behaviour as well as laser...

Broadband reflective multi-polarization converter based on single-layer double-L-shaped metasurface

In this paper, a broadband reflective multi-polarization converter based on single-layer double-L-shaped metasurface is proposed. The proposed metasurface can effectively convert linear-polarized (TE/TM) incident wave into the reflected wave with three different polarizations within the frequency bands of 5.5–22.75 GHz. Based on the electric and magnetic resonant features of the...

Ultrafast-laser dicing of thin silicon wafers: strategies to improve front- and backside breaking strength

Thin 50-µm silicon wafers are used to improve heat dissipation of chips with high power densities. However, mechanical dicing methods cause chipping at the edges of the separated dies that reduce the mechanical stability. Thermal load changes may then lead to sudden chip failure. Recent investigations showed that the mechanical stability of the cut chips could be increased using...