Papers by Keyword: Warm Conditions

Abstract: In this work, the hydroforming process in warm conditions was used for manufacturing an Al-Mg alloy (AA5754) benchmark component displaying different strain levels due to its geometry. The attention was focused on the effect of the rate to increase the forming pressure (PR), strictly related to the strain rate the material is subjected to. In fact, preliminary tensile and Nakajima tests (both at room temperature and in warm conditions) revealed that the mechanical and formability properties of the investigated alloy are strongly affected by the strain rate. Warm Hydroforming tests were conducted in order to investigate both the working temperature and the parameter PR. The Blank Holder Force profile was varied according to an experimentally determined profile able to avoid oil leakages. Experimental results were collected in terms of output variables related to the die cavity filling and to the strain level reached on the component: in such a way a multi-objective optimization could be carried out using the commercial integration platform modeFRONTIER. The best compromise between the high level of the component deformation and the cycle time could be obtained by conducting the warm hydroforming process at the temperature of 250°C and setting the parameter PR equal to 0.1 MPa/sec.

Abstract: In the present work the definition of a test procedure for evaluating the formability of Mg alloy thin sheets was investigated taking into account both temperature and strain rate. A numericalexperimental approach was adopted by the authors: numerical simulations were run with the aim of: (i) defining the punch geometry of the formability test equipment in order to have a uniform, fast and constant temperature distribution on the specimen; (ii) setting the test operating conditions in order to force the specimen failure in a region where temperature and strain can be easily acquired. Some formability tests were performed and strain fields were measured using an optical measurement system.