报告题目：Strength and Fracture Resistance in Laser Powder Bed-processed AlSi10Mg and 18Ni-300 Maraging Steel
报告内容简介：Engineering materials processed using additive manufacturing (AM) techniques such as laser powder bed fusion (LPBF) often exhibit unique microstructures and defects that must be controlled to obtain peak performance in mechanical properties. Towards this end, we here investigate how three heat-treatments (direct aging, solution treatment aging, and thermal cycling aging) impact microstructure evolution and corresponding mechanical performance of LPBF-processed 18Ni-300 maraging steel. Specifically, we focus on how strength and fracture toughness measured in two orthogonal directions correlate with phase transformation kinetics as well as micro- and meso-structural features and compare findings with results from as-built and conventionally processed material. Aging results in the formation of Ni–Ti and Mo-rich nano-precipitates that enhance strength but reduce both ductility and fracture resistance when compared to as-built material. With the solution treatment, however, AM-characteristics such as cellular sub-structures and melt-pool boundaries dissolve almost entirely and as a result the damage-tolerance capacity of the material degrades and becomes comparable to cast material. Thermal cycling, on the other hand, results in the formation of reverted austenite thereby enabling the transformation-induced plasticity (TRIP) effect. This leads to extensive gains in ductility that are accompanied by only moderate reductions in strength while fracture toughness is improved significantly. While anisotropy in the obtained data from both the tensile tests and the crack resistance curve (R-curve) measurements is noticeable, it is low relative to many LPBF-processed alloys due to the strong bonding characteristics between the individual layers.
报告人姓名：Professor Bernd Gludovatz
报告人简介：Bernd Gludovatz was educated at the University of Leoben in Austria where he received his M.S. in 2006 and his Ph.D. 2010, both in Materials Science and Engineering as a student of Prof. Reinhard Pippan. Subsequently he was working as post-doctoral fellow of Prof. Robert O. Ritchie at the Materials Sciences Division of the Lawrence Berkeley National Laboratory in the United States before joining UNSW as a Senior Lecturer of Mechanical and Manufacturing Engineering in 2017. His research interests are in the mechanical behavior of structural materials, particularly the mechanisms underlying deformation, fracture and fatigue of advanced metallic alloys, nature-inspired composites and biological materials. Additionally he is interested in the analysis of components that fail in service.
报告人单位(中文)：澳大利亚新南威尔士大学(UNSW)
报告时间：2022-10-11 11:00
报告地点：Zoom Meeting ID: 861 0999 7345 Passcode: 032558
主办单位：上海大学高性能金属增材制造国际化科研合作平台
联系人：陈超越
