Developing new Ti alloy for additive manufacturing – from pearlite to bainite

Guest Speaker：Vice Chancellor’s Senior Research Fellow Qiu Dong，RMIT University，Australia 

Inviter:  Assoc. Prof. Li Yangxin

Friday 1st December

10:00-11:30

Yiucheng Lecture Hall (500), Xu Zuyao Building

Biography

Dr Qiu was awarded a Ph.D degree majored in materials science and engineering from Tsinghua University in 2005. He had been working as a Postdoctoral Research Fellow, and then Australian Research Fellow at the University of Queensland from 2005 to 2014. Dr Qiu joined RMIT University in 2015 as a Vice Chancellor’s Senior Research Fellow. In the last 10 years, his research has spanned a range of areas, such as grain refinement of cast metals, crystallography in solid-solid phase transformations and surface modification of biomedical implants. His contribution to the research community is witnessed by 98 peer-reviewed journal papers, with 1 out of those published in Nature, 3 published in Nature Communications, 17 published in Acta Materialia, the leading journal in the field of physical metallurgy worldwide. His publications have been cited by more than 4500 times and his H-index is 37 in Scopus. He has also succeeded in obtaining fund of 5 Australian Research Council (ARC) Discovery Projects and 1 ARC Linkage Project. Dr Qiu is currently appointed as a Key Reader of ‘Metallurgical and Materials Transaction A’ and an ARC Assessor. His current research interest includes microstructure manipulation of additively manufactured (AM) metal components and new alloy development through AM.

Abstract

Novel ternary titanium alloys with a bainitic microstructure have been designed specifically for additive manufacturing. The Ti-Cu-Fe alloys take advantage of constitutional supercooling to suppress the growth of large columnar grains usually associated with AM Ti alloys. In the as-built condition the bainitic microstructure consists of a refined α-phase within a matrix of β-phase. The intermetallic phase, Ti2Cu forms prevalently on the interface of the α- and β-phase and within the β matrix. The high strength of these materials is attributed to the refined α-phase and Ti2Cu particles as well as significant solid solution hardening. This work demonstrates a viable way to fabricate structural components with unique and excellent properties using low-cost elemental powders with AM.