Development of the Fast Light Alloy Stamping Technology (FAST) towards automotive applications: experimental studies
File(s)
Author(s)
Ji, Kang
Type
Thesis
Abstract
In order to improve fuel efficiency and reduce carbon emissions for the automotive industry, a novel forming technology Fast light alloy stamping technology (FAST) for high and ultra-high strength aluminium alloy thin wall components (such as AA7075) was developed with experimental studies in this thesis. The process consists of: rapid heating, forming and in-die quenching, and incubation. A hot Stamping Simulator tool set to study FAST was successfully developed and manufactured to work in conjunction with the Gleeble 3800 thermo-mechanical testing machine. Based on this Hot Stamping Simulator, the effect of forming parameters on the formability of material and post-form strength have been studied for AA7075 2 mm blank. The effects of contact pressure, lubricant, and tool material on the Interfacial heat transfer coefficient (IHTC) have also been studied, and a mathematical model was developed in order to calculate the quenching time, predict post form strength and optimise the tool design to secure a high quenching rate, enabling the full post-form strength to be retained. Verification tests for the FAST process utilising AA7075 2 mm blank were conducted by forming U-shape and M-shape components. A standard testing procedure was developed for different materials and manufacturer requirements and was verified by studying 6 test cases. Finally, as a new forming process, conclusions and recommendations are made outlining additional factors to be studied to enable the FAST process to be adopted in an industrial environment.
Version
Open Access
Date Issued
2017-11
Date Awarded
2018-02
Copyright Statement
Creative Commons Attribution Non-Commercial No Derivatives licence
Advisor
Wang, Liliang
Lin, Jianguo
Publisher Department
Mechanical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)