In situ differential thermal analysis device for evaluating high-speed phase transitions

Autor(es)

Sanchez Roca, Angel ^[1] ; Carvajal Fals, Hipolito Domingo ^[1] ; Zoqui, Eugenio Jose ^[2]

Afiliação do(s) autor(es)

^[1] Univ Oriente, Sch Mech Engn, Mfg & Mat Dept, Santiago De Cuba 90400 - Cuba

^[2] Univ Campinas UNICAMP, Sch Mech Engn, Mfg & Mat Dept, BR-13083860 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY; v. 134, n. 3, p. 1589-1597, DEC 2018.
• Citações Web of Science: 2

Resumo

Thixoforming involves heating different types of alloys to the semisolid state at high heating rates and forming in die-casting machines or conventional presses. At temperatures higher than the solidus and lower than the liquidus, the mush metal behaves like a high-viscosity thixotropic material. Therefore, determining the thermodynamic behavior of the solid-to-liquid transition is paramount to control thixoforming processes. This article describes a simple, novel experimental setup based on differential thermal analysis (DTA) for analyzing the phase transitions in an alloy heated using high heating rates typical of industrial applications. A365 alloy was chosen to demonstrate the effectiveness of the method as the phase transformations for this alloy in semisolid materials (SSM) processing are well understood. Samples were heated to 750 degrees C using constant linear heating rates of 5, 10, 15, 20, 25, 50, 75, 100 and 125 degrees C min in a Norax 25kW 8kHz induction furnace with an Omron E5CK temperature controller. AISI 316 austenitic stainless steel was used as the inert reference. Comparison of the results of DTA using the proposed method and the results of simulation with Thermo-Calc((R)) indicates that the proposed in situ DTA device and its method is suitable for analyzing phase transitions when high heating rates are used. (AU)

• Processo FAPESP: 15/22143-3 - Resistência à fadiga de ligas metálicas tixoconformadas
• Beneficiário: Eugênio José Zoqui
• Modalidade de apoio: Auxílio à Pesquisa - Regular