| Resumo : |
This study focuses on the characterization of thermoplastic composites for use in the automotive industry and provides an exhaustive survey of thermal and viscoelastic parameters to introduce a thermostamping simulation model. The study includes an analysis of the mechanical, physical and chemical properties of the composites, as well as an investigation of their crystallization kinetics using Avrami and Hillier kinetic models. The study involves Differential Scanning Calorimetry (DSC) techniques, Dynamic Mechanical Analysis (DMA), density analysis, residual stress measurements, which were important to determine the thermal and viscoelastic properties of the composites. The DSC results were treated from the Avrami model and lfillier of the main parameters that were studied, there are the Avrami constants, which vary from 1.74 to 2.81. From the study of densities, the fiber volumetric fraction value of 52.7673 was obtained. Residual stress tests reveal material bending due to thermal expansion mismatch. the thermal expansion coefficient calculated was 1.73E-05, this result compared with the literature, validates the methodology and improves the understanding of the material properties. The parameters obtained from all the tests were used to contribute to the scope of the ROTA 2023 project (contract No. 00081/2021), under development with LEL-IPT, Maxion, FHS Importaria, Stampway, IVECO and Stellantis, which aims to development of the simulation of the thermostamping process, in order to improve its design and processing quality for use in automotive applications, reducing raw material and, consequently, costs. Therefore, this work aimed to provide a survey of the thermal and viscoelastic parameters of the composite material Toray Cetex TC910 PA6 and the pure material PA6 Aegis@ H8202NLB, using thermal and viscoelastic analysis, providing input data for the prediction of residual stresses and geometric distortions in thermoplastic composite parts. |