Materials Frontier No.119
Title:Atom Probe Tomography and its Applications for New Insights into Advanced Materials
Speaker:Dr Gang Sha (沙刚博士), Senior Researcher, Australian Centre for Microscopy & Microanalysis, School of Aerospace, Mechanical & Mechatronic Engineering, The University of Sydney, Australia
Venue: Room.308, Material Building A
Inviter: Prof.Zhang Deliang
Dr. Gang Sha is an internationally-known expert in atom probe tomography, with 12-years experience in the applications of this analysis technique in materials research. He obtained his DPhil degree at University of Oxford in 2002, and subsequently worked in two internationally-leading atom-probe research groups, at University of Oxford, and at University of Sydney. He is the author of over 65 publications including 11 papers in Acta Materialia. His publications currently received more than 560 citations and have an h index of 14 according to Scopus. Over the last 5 years, he was frequently invited to give invited lectures at various national and international conferences including TMS2013, TMS2012, TMS2010 and AMPT2012, and served as session chairs at TMS2013, LMT2013 and AMPT2012. His current research interests focused on the application of atom probe technique to understand advanced materials including steels, light metals and nanocrystalline materials, and to address field-ion evaporation physics.
Over the last 10 years, several important technology breakthroughs have been made in atom probe tomography (APT). This led to the success commercialisation of local-electrode atom probes (LEAP) in 2004. Since then, more than 50 instruments have been installed in world-leading research labs and R&D centres in major industries including steel, electric power, electronics and semiconductors around the world. With laser-pulsing technology, APT can analyse not only conductors but also poor conductive materials such as ceramics. Atom probe tomography (APT) is getting popular, and is becoming a main-stream characterisation tool in unveiling the three-dimensional structural and chemical information of advanced materials. In this talk, the speaker will provide a brief overview of the APT technology development, outline basic principles of this analysis technology, and give an introduction of sample preparation techniques, data reconstruction and data analysis, and present a brief summary of the major applications of the analysis technique in a variety of advanced material research. Based on his recent work in light metals, he will present two case studies to illustrate what we learn from ZK60 Mg alloys and ultrafine-grained Al alloys processed by high-pressure torsion. In particular, precipitation reactions, the segregation and partitioning behaviours of solute atoms and their effects on strength and grain refinement of UFG materials will be discussed in this presentation.