Development of a new heat stamping process for titanium alloy panel components
File(s)
Author(s)
Tian, Famin
Type
Thesis
Abstract
The aim of the project is to develop a new cost-effective and energy-efficient Heat Stamping (HS) process for forming complex-shaped titanium alloy panel components with high productivity. In this new process, the hot Ti-6Al-4V panel is heat treated at a designated soaking temperature and rapidly quenched to a lower forming temperature, at a cooling rate of 50 °C/s, for fast stamping. Comprehensive experiments on Ti-6Al-4V have been conducted to investigate the metallurgical and thermomechanical responses, and their interactions, under both hot stamping and HS conditions. Mechanism-based viscoplastic constitutive model and phase transformation model for Ti-6Al-4V under Heat Stamping conditions has been developed and calibrated using experimental data. Finite element modelling system has been established, with the implementation of the material models via subroutine, for simulation and optimisation of the HS process. The feasibility study of the HS process has been carried out using a designed laboratory-scale HS system.
The thermo-mechanical properties of Ti-6Al-4V after Direct Heating (DH) and Step Quenching (SQ) heat treatment routes were investigated through high temperature uniaxial tensile tests, at temperatures in the range of 750 - 950 °C and the strain rates of 0.1 - 5 /s, with a new contactless strain measurement method. The hot deformation mechanisms in DH tests were analysed, and the effect of SQ heat treatment on flow softening reduction and strain rate hardening enhancement was investigated...
The thermo-mechanical properties of Ti-6Al-4V after Direct Heating (DH) and Step Quenching (SQ) heat treatment routes were investigated through high temperature uniaxial tensile tests, at temperatures in the range of 750 - 950 °C and the strain rates of 0.1 - 5 /s, with a new contactless strain measurement method. The hot deformation mechanisms in DH tests were analysed, and the effect of SQ heat treatment on flow softening reduction and strain rate hardening enhancement was investigated...
Version
Open Access
Date Issued
2023-08-10
Date Awarded
2023-11-01
Copyright Statement
Attribution-Non Commercial-No Derivatives 4.0 International Licence (CC BY-NC-ND)
Advisor
Li, Nan
Childs, Peter
Lin, Jianguo
Publisher Department
Dyson School of Design Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)