Arc-Wire based additive manufacturing – Dr Nicholas Paul Hoye

Characterisation of Ti-6AL-4V deposits produced by arc-wire based additive manufacture – University of Wollongong

Dr Nicholas Hoye was awarded his PhD degree in 2015. The primary aim of his postgraduate research project was to investigate the use of arc-wire deposition techniques based on the gas tungsten arc welding process for the additive manufacture of freeform structures from the Ti-6Al-4V titanium alloy. Nick focused on four key aspects of the process; characterisation of geometry and microstructure of additively manufactured structures; evaluation of mechanical properties; influence of welding process parameters on residual stresses in these structures; and extent and effects of atmospheric contamination during the manufacturing process. Mechanical testing indicated comparable properties between conventionally process and additively manufactured materials, with post-weld atmospheric contamination having no discernible effect on the properties of the bulk. Additionally, it was shown that conventional post-weld heat treatments are effective in relieving residual stresses formed during the additive manufacturing process.

Dr Hoye’s research contributed significantly to DMTC Project 1.3 – Evaluation of Titanium Direct/Additive Manufacture. The findings of this work indicate that the arc-wire based additive manufacture process shows promise in substantially reducing the manufacturing costs associated with structural titanium components by increasing material utilisation and reducing machining requirements. The outcomes of the project were also considered to be a foundation in the development of knowledge and enabling technologies for defence OEMs and supply chain manufacturers within Australian industry.

With his postgraduate studies completed, Dr Hoye has taken a research fellow position at the University of Wollongong. This has seen him continue collaborative research with both the DMTC and the Industrial Liaison Office of the Bragg Institute at the Australian Nuclear Science and Technology Organisation (ANSTO). In addition to his industrially focused research activities, Dr Hoye is actively involved in the development and delivery of course materials and teaching aids for undergraduate engineering subjects at the University of Wollongong.