title: 3D online submicron scale observation of mixed metal powder's microstructure evolution in high temperature and microwave compound fields.
abstract: In order to study the influence on the mechanical properties caused by microstructure evolution of metal powder in extreme environment, 3D real-time observation of the microstructure evolution of Al-Ti mixed powder in high temperature and microwave compound fields was realized by using synchrotron radiation computerized topography (SR-CT) technique; the spatial resolution was enhanced to 0.37  μm/pixel through the designed equipment and the introduction of excellent reconstruction method for the first time. The process of microstructure evolution during sintering was clearly distinguished from 2D and 3D reconstructed images. Typical sintering parameters such as sintering neck size, porosity, and particle size of the sample were presented for quantitative analysis of the influence on the mechanical properties and the sintering kinetics during microwave sintering. The neck size-time curve was obtained and the neck growth exponent was 7.3, which indicated that surface diffusion was the main diffusion mechanism; the reason was the eddy current loss induced by the external microwave fields providing an additional driving force for mass diffusion on the particle surface. From the reconstructed images and the curve of porosity and average particle size versus temperature, it was believed that the presence of liquid phase aluminum accelerated the densification and particle growth.
authors.affiliation: CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Dan
authors.identifier: 0000-0001-7338-3688
authors.initials: D
authors.lastname: Kang
authors.affiliation: CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.affiliation: CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Xiao-fang
authors.initials: XF
authors.lastname: Hu
authors.affiliation: CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Bo
authors.identifier: 0000-0002-5310-2671
authors.initials: B
authors.lastname: Dong
authors.affiliation: CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China.
authors.forename: Ti-qiao
authors.initials: TQ
authors.lastname: Xiao
mesh_terms: D000535:Aluminum / Q000737:chemistry; D007700:Kinetics; D008872:Microwaves; D013696:Temperature
chemical_list: D000535:Aluminum
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