Investigation of the thermoelectrical properties of the Sn91.2-x–Zn8.8–Agx alloys

Sn91.2-x–Zn8.8–Agx alloys (x = 0.15–10.0 wt%) were directionally solidified upwards at a constant G (4.16 K mm-1) and V (41.5 µm s-1) in a Bridgman-type directional solidification furnace. The electrical resistivity (?) measurements of the alloys depending on the temperature were performed using the standard four-point probe method, and the temperature coefficients of the resistivities (?) were calculated. Composition analyses of the alloys were carried out using energy-dispersive X-ray spectroscopy. The enthalpy (?H) and the specific heat (?Cp) values of the alloys were determined by differential scanning calorimetry analysis. The thermal conductivity (K) values were obtained from the Wiedemann–Franz equation. According to the experimental results, electrical resistivities increased up to 3.0 mass% Ag and decreased with further increase in Ag content. Enthalpy and specific heat values decreased with the increasing content of Ag. The results were compared with the previous works for Sn–Zn–Ag alloys. © 2017, Akadémiai Kiadó, Budapest, Hungary.Ömer Halisdemir ÜniversitesiAcknowledgements This project was supported by the Nig^de Ömer Halisdemir University Scientific Research Project Unit under Contract No: FEB 2013/18. The authors would like to thank to Nig^de University Scientific Research Project Unit for their financial support

Analysis of ESAFORM 2021 cup drawing benchmark of an Al alloy, critical factors for accuracy and efficiency of FE simulations

This article details the ESAFORM Benchmark 2021. The deep drawing cup of a 1 mm thick, AA 6016-T4 sheet with a strong cube texture was simulated by 11 teams relying on phenomenological or crystal plasticity approaches, using commercial or self-developed Finite Element (FE) codes, with solid, continuum or classical shell elements and different contact models. The material characterization (tensile tests, biaxial tensile tests, monotonic and reverse shear tests, EBSD measurements) and the cup forming steps were performed with care (redundancy of measurements). The Benchmark organizers identified some constitutive laws but each team could perform its own identification. The methodology to reach material data is systematically described as well as the final data set. The ability of the constitutive law and of the FE model to predict Lankford and yield stress in different directions is verified. Then, the simulation results such as the earing (number and average height and amplitude), the punch force evolution and thickness in the cup wall are evaluated and analysed. The CPU time, the manpower for each step as well as the required tests versus the final prediction accuracy of more than 20 FE simulations are commented. The article aims to guide students and engineers in their choice of a constitutive law (yield locus, hardening law or plasticity approach) and data set used in the identification, without neglecting the other FE features, such as software, explicit or implicit strategy, element type and contact model