报告题目(英文)：Additive manufacturing of titanium alloys
报告时间：2015-07-06 09:00
报告地点：上海大学日新楼410
报告人姓名：Dr.Ma Qian
报告人简介(英文) ：Dr. Ma Qian is the professor of RMIT University (Royal Melbourne Institute of Technology), Melbourne, Australia and deputy director of RMIT Centre for Additive Manufacturing. He is also an honorary professor of Materials Engineering of the University of Queensland and a specially appointed professor of Osaka University Japan.
Professor Ma Qian current main research interesting include additive manufacturing or 3D metal printing; powder metallurgy; solidification processing; heterogeneous nucleation and grain refinement; and titanium implant materials. He has published more than 150 refereed journal papers more than 2500 of Scopus citations. He is an Advisory Editor of Elsevier Inc on Powder Materials and Solidification. In addition, he currently serves on the editorial boards of a number of journals including Metallurgical and Materials Transactions A, JOM, Powder Metallurgy, International Journal of Powder Metallurgy, ActaMetallurgicaSinica, Journal of Korean Powder Metallurgy Institute etc. He is a board member of the Asian Powder Metallurgy Association.
报告内容简介：Metal additive manufacturing (AM) processes are poised to transform the metal manufacturing industry, particularly in those areas where conventional manufacturing reach its limitation in terms of both design freedom and manufacturing capabilities. There are a number of different metal AM systems available today, including the powder-bed, powder-fed, and wire-fed systems. Currently there are already 29 common metal powder materials available for AM, including stainless steels, aluminium, nickel, cobalt-chrome and titanium alloys. Ti-6Al-4V (in wt.%) is the most extensively studied alloy to date in the context of metal AM. This two-hour lecture first presents a concise overview of metal AM and then discuss recent process in fabricating strong and ductile Ti-6Al-4V by selective laser melting (SLM). The SLM-fabricated Ti-6Al-4V often consists of columnar prior-β grains filled with acicular martensite, which displays high yield strength (>1100 MPa) but limited and inconsistent tensile ductility (e.g. 2% to 8% of tensile elongation). To circumvent this challenge, a new concept has been introduced to produce ultrafine α-β lamellar structures in the as-built Ti-6Al-4V via in-situ decomposition of martensite through an appropriate selection of SLM processing windows. The resulting unstable martensitic structure transformed into an ultrafine type of lamellar α-β structure via in-situ martensitic decomposition. The novel ultrafine microstructure thus produced attained a desired combination of yield strength (>1100 MPa) and elongation to failure (>11%) and decent high cycle fatigue properties. The last part of this lecture discusses the speaker's current perspectives on additive manufacturing of titanium alloys.
报告人单位(英文) ：RMIT University (Royal Melbourne Institute of Technology), Melbourne, Australia
