Effect of FEM choices in the modelling of incremental forming of aluminium sheets

peer reviewedThis paper investigates the process of single point incremental forming of an aluminium cone with a 50-degree wall angle. Finite element (FE) models are established to simulate the process. Different FE packages have been used. Various aspects associated with the numerical choices as well as the material and process parameters have been studied. The final geometry and the reaction forces are presented as the results of the simulations. Comparison between the simulation results and the experimental data is also made

An FEM-aided investigation of the deformation during single point incremental forming

Incremental forming is an innovative and flexible sheet metal forming technology for small batch production and prototyping, which does not require any dedicated die or punch to form a complex shape. This paper investigates the process of single point incremental forming of an aluminium cone both experimentally and numerically. Finite element models are established to simulate the process. The output of the simulation is given in terms of final geometry, the thickness profile of the product and the strain history and distribution during the deformation. Comparison between the simulation results and the experimental data is made

Experimental validation of the finite element simulation of the first stroke in single point incremental forming

peer reviewedSingle-point incremental forming (SPIF) is a sheet metal forming technique that has gained particular interest in rapid prototyping and small volume production. The study of the underlying forming mechanisms is supported by new developments in finite element simulations and experimental full field strain measurements. This article aims to describe the possibilities and difficulties encountered during validation of finite element predictions of the incremental forming process. The drawing of a straight line into a metal plate was selected as a first test case for this kind of validation. Results of both finite element simulation and experimental work will be discussed

Carbocatalysis by graphene-based materials

[EN] Carbon materials derived from biomass are considered paradigmatic examples of sustainability.6,7 Other factors besides sustainability that may also favor carbon-based versus inorganic materials as catalysts are economic considerations, since the price of some precious metals is considerably higher than the feedstock carbon materials. For these reasons, there is much interest in developing metal-free catalysts; carbocatalysis is one of the most important examples of this tendency to reduce the dependency on metalsFinancial support by the Spanish Ministry of Economy and Competitiveness (MINECO, Severo Ochoa program, CTQ 2012-32315 and CTQ2010-18671) and Generalitat Valenciana (GV/2013/040) is gratefully acknowledged. A.D.M. thanks University Grants Commission, New Delhi for the award of Assistant Professorship under its Faculty Recharge Programme.Navalón Oltra, S.; Dhakshinamoorthy, A.; Alvaro Rodríguez, MM.; García Gómez, H. (2014). Carbocatalysis by graphene-based materials. Chemical Reviews. 114(12):6179-6212. https://doi.org/10.1021/cr4007347S617962121141

Generating Ionic Liquids from Ionic Solids: An Investigation of the Melting Behavior of Binary Mixtures of Ionic Liquids

Mixtures of ionic liquids (ILs) allow enlarging the plethora of the physical and chemical properties of these materials in addition to the well-known tunable character associated with pure compounds. It is shown here that mixtures also induce a significant decrease of the melting points of the mixture to values well below those of the original compounds allowing the tuning of the melting point of an ionic liquid mixture and the generation of novel ionic liquids from mesotherm salts. This work evaluates the melting behavior of mixtures of seven hexafluorophosphate-based compounds combined with imidazolium-, pyridinium-, pyrrolidinium-, piperidinium- ammonium-, or phosphonium-based cations. The solid-liquid equilibrium phase diagrams of nine of their binary mixtures were measured using optical microscopy and differential scanning calorimetry. The pure ILs' melting profile reveals the presence of polymorphs with highly energetic solid-solid transitions that are relevant for the evaluation of these systems. The phase diagrams reported here also allow an investigation on the nonideality of the mixtures of ionic liquids. A classical thermodynamic approach shows that while most of the mixtures investigated present an ideal liquid behavior, others show slight or even marked nonideal profiles. One particular system, [C(3)mpyr][PF6] (1-methyl-1-propylpyrrolidinium hexafluorophosphate) + [C(3)mpip][PF6] (1-methyl-1-propylpiperidinium hexafluorophosphate), displays a continuous solid solution as established by differential scanning calorimetry, powder X-ray diffraction, and crystallographic data being one of the few ionic liquid alloys ever reported