Mechanical behavior of a Ti‐6Al‐4 V titanium alloy with microstructural evolution modeling under hot and superplastic conditions

Abstract

The present work aims at evaluating and understanding the mechanical behavior of a Ti‐6Al‐4 V alloy under hot and superplastic forming conditions. Tensile tests were performed at temperature range from 650 °C to 950 °C, at strain rates between 10‐2 s‐1 and 10‐4 s‐1. Three equiaxed microstructures, each characterized by a different starting grain size (4.9 μm, 3.0 μm and 0.5 μm), are compared to better understand the microstructural evolutions under hot and superplastic forming conditions and their influence on the mechanical behavior. Hence, an accurate model with microstructural considerations is proposed. The model capabilities consider the grain size evolution that is influenced by the temperature and deformation. The computed flow stresses strongly depend on the strain rate and on the considered initial grain size. Temperature and strain rate conditions may lead to a strain hardening phenomenon in some cases. The comparison between the model response and experiment shows a good agreement for all the tests carried out on Ti‐6Al‐4 V.

Mechanical Behavior of Ti-6Al-2Sn-4Zr-2Mo Titanium Alloy under Hot and Superplastic Forming Conditions: Experiment and Modeling

“…These tests examined, on the one hand, the microstructure qualified by the aircraft industry and, on the other hand, a new range of refined microstructures obtained by a hot straining process. Depending on the test conditions, microstructural observations exhibited complex phenomena, simultaneously including both grain growth [2,3] and dynamic recrystallization (DRX) [4]. These phenomena greatly influence the mechanical behavior with regard to strain hardening or softening, and can drastically reduce the maximal elongation or, on the contrary, increase it.…”

A Study on Modelling the Superplastic Behaviour of Ti54M Alloy

“…Finite element modelling has a significant role in manufacturing these parts economically by saving the costs of experimental trials. Titanium (α + β) alloy Ti-6Al-4V (Ti64) is extensively used in SPF to form parts for aerospace applications due to its high strength to weight ratio and excellent corrosion resistance [2,3]. TIMETAL ® 54M (Ti54M) is another titanium (α + β) alloy that has almost the same mechanical properties of Ti64 alloy but superior machinability [4].…”