Prediction and Experiment of Fracture Behavior in Hot Press Forming of a TA32 Titanium Alloy Rolled Sheet

Abstract

In aerospace and automotive industries, hot press forming (HPF) technology is widely used for rapid and precise deformation of the complex sheet metal component, where the fracture behavior has always been a focused problem. In this study, the hot tensile test and the Nakazima test were carried out, in order to establish the Misiolek constitutive equation and determine the forming limit strain points at an elevated temperature, respectively. The microstructure evolution during the tensile test was also investigated by optical microscope. In addition, the Marciniak–Kuczynski (M–K) model, considering the Mises, Hill48, and Logan–Hosford yield criteria, was utilized to calculate the theoretical forming limit curve (FLC). Furthermore, the fracture behavior of the TA32 alloy sheet during the HPF process was accurately predicted by inserting the predicted FLC into finite element simulation, and the qualified complex component was obtained by optimizing the shape of the sheet.

Study of Alloy Hot Flow and Hardening Behavior Using a New Correction Method for Hot Uniaxial Tests

“…To model the angle variation, a phenomenological expression of angle as a function of temperature and strain rate is proposed in Equation (2).…”

“…Titanium alloys are advanced materials with a superior strength-to-weight ratio and high corrosion resistance [1,2] and have been widely applied in the aerospace, marine and transportation industries. Thin-walled titanium alloy components are one of the dominant load-bearing structures in those industries [3].…”

Modelling and Simulation of Sheet Metal Forming Processes

“…Researchers were invited to submit innovative research papers on modelling and numerical simulation of sheet metal forming processes. Thirteen research papers were published in this Special Issue of Metals, entitled "Modelling and Simulation of Sheet Metal Forming Processes", which highlight some of the research trends in the field [2][3][4][5][6][7][8][9][10][11][12][13][14].…”

“…For these reasons, different theoretical approaches have been develop for the prediction of FLDs, among which the Marciniak-Kuczynski (M-K) theory [17] is the most widely applied. In their paper, Fan et al [10] used the M-K theory to predict the FLD for a TA32 alloy, for a temperature range between 700 • C and 800 • C, taking into account strain rate effects. The parameters of the thermomechanical hardening law considered in the M-K theory were fitted using experimental results from hot tensile tests.…”

“…Nevertheless, the identification of the anisotropy parameters of these type of yield criteria requires experimental data covering a wide range of stress/strain paths. In the collected works, the characterization of the mechanical behaviour of the metallic sheets was mainly performed with uniaxial tensile tests [3,4,6,7,10,13], although some researchers have also resorted to shear tests [3,9,11]. Simões et al [8] presented a numerical study that contributes for the understanding of the mechanical phenomena that occur in the material under Knoop indention, enhancing and simplifying the analysis of the results obtained in Depth-sensing indentation tests.…”