报告题目：Additive manufacturing of ultrafine-grained high-strength titanium alloys

报告人：邱冬 教授

主持人（邀请人）： 王慧远 教授

报告时间：2019年12月18日14:00-16:00

报告地点：南岭校区逸夫机械材料馆209学术报告厅

主办单位：材料科学与工程学院、汽车材料教育部重点实验室

摘要：

Additively manufactured (AM) titanium alloys have been used in numerous applications, in particular in the biomedical and aerospace industries due to the greater material efficiency and enhanced design flexibility. However, for many conventional titanium alloys, the AM process usually results in a microstructure comprised of coarse columnar grains, which often leads to undesirable anisotropic mechanical properties. In contrast to other common engineering alloys, such as aluminium, there is no commercial grain refiner, containing potent inoculants that can survive in liquid titanium, able to control microstructure effectively. To address this challenge, we have developed a novel technique for AM by using Ti-Cu alloys with a high constitutional supercooling capacity that overrides the negative effect of a high thermal gradient in the melt pool during AM. Through this approach, it is shown that an as-printed Ti-Cu alloy specimen is comprised of fully equiaxed, fine grained microstructure without any special process control or additional subsequent treatment. The new AM Ti-Cu alloys also display promising mechanical properties, compared to conventional alloys under similar processing conditions, due to the formation of an ultrafine eutectoid microstructure by taking full advantage of the high cooling rates and multiple thermal cycles in the AM process. We anticipate that this approach will be equally applicable to other eutectoid forming alloy systems.

报告人简介：

邱冬，教授，2005年在清华大学材料科学与工程系获得工学博士学位，之后前往澳大利亚昆士兰大学先后以UQ Postdoc Fellow和 Australian Research Fellow的身份从事镁合金、铝合金、锌合金以及铁素体/奥氏体钢等多种工程合金凝固过程中高效晶粒细化剂的开发。2015年被皇家墨尔本理工大学（RMIT）聘为校长特聘高级研究员，开始介入金属3D打印（增材制造）领域，现在主要从事适合增材制造特点的新型工程合金的设计与开发，以及对3D打印过程中微观组织的调控与优化。截止到2019年12月，邱冬博士以主要参与人的身份共获得4次澳大利亚自然科学基金（ARC Discovery Project）和1次应用创新基金（ARC Linkage Project）的资助，发表了80篇经同行评议的期刊论文，其中包括1篇以共同一作身份发表在Nature正刊，以及16篇论文发表在物理冶金领域知名期刊Acta Materialia上，在Scopus搜索引擎上论文被引用总数达1900余次，H因子为25。现担任物理冶金学报（Metallurgical and Materials Transaction A）审稿委员会委员（key reader），澳大利亚自然科学基金评审专家，2017年被437ccm必赢国际聘为“唐敖庆”讲座教授。