The absorptivity of a material is major uncertainty in numerical simulations laser welding and additive manufacturing, its value often calibrated through trial-and-error exercises. This adversely affects the capability when predicting process behaviour can eventually hinder exploitation fully digitised manufacturing processes, which goal "industry 4.0". In present work, an enhanced absorption model that takes into account effects characteristics, incident angle, surface temperature,...

A critical characteristic of β-Ti alloys is the inevitable formation ω-precipitates during certain heat treatments which leads to embrittlement, or even a complete loss ductility. Therefore, alloy design with goal inhibit elementary ω-formation process utmost importance. Here, we propose strategy for prototypical β-type Ti–Cr–(Mo) alleviate this problem using only minor additions Sn. Upon addition Sn, observed an extensive deceleration suppression kinetics isothermal ageing. Furthermore,...

Modeling the thermal and fluid flow fields in laser-based directed energy deposition (DED-LB) is crucial for understanding process behavior ensuring part quality. However, existing models often fail to accurately predict these due simplifying assumptions, particularly regarding powder particle-induced attenuation laser power density distribution, variable material properties parameters. The present work introduces a high-fidelity multi-phase thermal-fluid model driven by combination of...

In Laser-based Directed Energy Deposition (L-DED) the laser-induced spatial and temporal thermal cycles strongly determine microstructure of deposited layers. The effect three different laser intensity profiles (beam shapes) on shape melt pool resulting was studied. To this end, gradients growth rates, derived from measured emissions, are compared to characteristics in tracks. These obtained using Electron Back Scatter Diffraction (EBSD). It found that beam affects morphology. Therefore it...

The Friction Screw Extrusion Additive Manufacturing (FSEAM) process is a newly created for additive manufacturing of low weight-high strength aluminum and magnesium alloys in the solid state which are unsuited many fusion-based approaches. based on rotating threaded tool located within stationary housing that equipped with feeding mechanism. dimensions shape deposited layers can be controlled through dedicated printhead design. This work reports results fabrication rectangular structures...

In titanium alloys, the $\ensuremath{\omega}$(hexagonal)-phase transformation has been categorized as either a diffusion-mediated isothermal or an athermal that occurs spontaneously via diffusionless mechanism. Here we report $\ensuremath{\omega}$ can occur even above temperature. body-centered cubic $\ensuremath{\beta}$-titanium alloyed with $\ensuremath{\beta}$-stabilizing elements, there are locally unstable regions having fewer elements owing to quenched-in compositional fluctuations...

Currently, it is challenging to obtain consistent values for the anisotropic electrical conductivity of fabric ply based thermoplastic composites. In this study, type material was obtained by combining six-probe voltage measurements with a numerical evaluation method process measurements. The effect probe distance and specimen dimensions on test results investigated. show low variability conductivities agree rule mixtures two-probe measurement method. conducted research shows that one...

Abstract Solid-state additive manufacturing constitutes a worthwhile alternative for many precipitation-based aluminium alloys that cannot be processed through fusion-based approaches due to metallurgical problems. In this work, the newly developed solid-state friction screw extrusion (FSEAM) approach has been employed study processability of AA6060 T6 as function printing velocity. Various wall-like builds were fabricated at velocities 100 mm/min 250 by deposition 50 layers 1 mm thickness,...

Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable bulk metallic alloy samples is available routine use. In this work a dilatometer temperature isothermal and non-isothermal in range from room to 1300 K presented. The length measuring system based on two-beam...

Long-term fixation of orthopaedic implants can be enhanced by tissue ingrowth techniques. As such, the deposition a bioactive bone-like coating could considered promising method to facilitate integration onto bone tissue. In this study, we identified optimized osteo-conductive Calcium Phosphate (CaP) parameters for on PolyCarbonate-Urethane (PCU) foils. The oxygen plasma surface-activated PCU specimens were suspended in simulated body fluid (SBF) and supersaturated SBFs 4 h, 8 24 or 6 days...

The present case study demonstrates that high-precision dilatometry serves as sensitive tool for quantitatively characterising precipitation processes down to small relative length changes in the range of and covering long time scales exceeding s. For a dilute Al-based Al–Mg–Si alloy, amount metastable coherent -phase semicoherent well stable β-phase could be determined on an absolute scale from in-situ change measurements upon long-time isothermal annealing. quantitative analysis allows...

Many of the macroscopic properties a glass are determined by degree structural relaxation. When nonequilibrium system ages toward thermodynamically more favorable state, accompanying densification leads to an increase activation energies found for $\ensuremath{\alpha}$ and especially $\ensuremath{\beta}$ relaxation processes. In this work we experimentally quantify low-energy mechanical spectrum metallic at cryogenic temperatures, show that these processes intriguingly opposite trend. The...

Abstract A detailed understanding of the kinetics phase formation in $$\beta $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>β</mml:mi> </mml:math> -stabilised titanium is decisive importance for applicability these materials. However, complex nature and long timescales various transformations, calls specialized measurement techniques. In this work high-stability isothermal laser dilatometry used to study temporal volume changes associated with processes. Distinctly...

Starting from fundamental aspects of thermal vacancies and solid-state self-and solute diffusion, this paper reviews procedures for tracer-and interdiffusion studies the major techniques vacancy by dilatometry positron annihilation in metals. Equilibrium diffusion performed on pure iron aluminium are mentioned at first. We also comment some peculiarities aluminium. Positron differential Fe-Al alloys with various compositions summarized new experimental authors reported migration Fe 61 Al 39...

The synthesis of bulk nanoporous copper (npCu) from a copper-manganese alloy by electrochemical dealloying and free corrosion as well the behaviour dealloyed structures is investigated

The Friction Screw Extrusion Additive Manufacturing (FSEAM) process is a newly created for additive manufacturing of low weight-high strength aluminium and magnesium alloys in the solid state which are unsuited many fusion-based approaches. based on rotating threaded tool located within stationary housing that equipped with feeding mechanism. dimensions shape deposited layers can be controlled through dedicated printhead design. Integrated cooling facilities help to control temperature.This...

A novel method for defining the measured electrical conductivity of CFRTP in induction heating simulations is presented. This considers conductivity’s orientation dependence and accurately predicts electromagnetic transient temperature fields. The study demonstrates that predictions using present model are good agreement with experiments, it yields improved field compared to other models.

High-precision LASER dilatometry with a unique measurement setup was applied to the bulk metallic glass alloy ${\mathrm{Zr}}_{52.5}$${\mathrm{Ti}}_{5}$${\mathrm{Cu}}_{17.9}$${\mathrm{Ni}}_{14.6}$${\mathrm{Al}}_{10}$ (Vit105) for specific volume studies. Employing small temperature steps of $\ensuremath{\Delta}T=5$ and 10 K long times effective heating rates order ${10}^{\ensuremath{-}2}$ K/min were realized changes measured resolution $\ensuremath{\Delta}V/V={10}^{\ensuremath{-}6}$ down 573...

The design of specific material properties aluminum alloys demands for a detailed understanding clustering and precipitation processes occurring during heat treatments. Positron lifetime spectroscopy in combination with high-precision dilatometry measurements were taken, allowing comprehensive analysis the aging mechanisms on different timescales temperature regimes, artificial aging. From results, unambiguous experimental evidence following three main steps process is obtained. In first...

For fcc concentrated solid-solution alloys (CSA), the concentration of quenched-in thermal vacancies was experimentally determined by direct and vacancy-specific technique positron annihilation lifetime spectroscopy. Whereas with only three constituents in nonequimolar fractions (CrFeNi) exhibit vacancy concentrations about 10${}^{\ensuremath{-}5}$, CSA (CoCrFeNi, CoCrFeMnNi) four or five equimolar components do not show a lifetime. Hence, there is either vanishingly small...