Characterization of high-pressure die-cast hypereutectic Al-Si alloys based on microstructural distribution and fracture morphology |
| |
| Affiliation: | 1. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;2. State Key Laboratory of Automobile Safety and Energy, Tsinghua University, Beijing, China;3. China FAW Foundry Co., Ltd., Changchun 130011, China;1. Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Materials Science and Engineering, Beihang University, Beijing 100191, China;2. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics Chinese Academy of Sciences, Beijing 100190, China;3. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China;1. National Engineering Research Center of Light Alloys Net Forming and State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University, Shanghai 200030, PR China;2. National Engineering Research Center of Light Alloys Net Forming, Shanghai 200030, PR China;1. National Engineering Research Center of Light Alloy Net Forming and Key State Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiaotong Univerisity, Shanghai, 200240, China;2. Shanghai Light Alloy Net Forming National Engineering Research Center Co., Ltd., Shanghai, 201615, China;1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;2. Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;1. Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA;2. Alcoa Technical Center, New Kensington, PA 15068, USA;3. Department of Integrated Systems Engineering, The Ohio State University, Columbus, OH 43210, USA |
| |
| Abstract: | The fracture behavior of high-pressure die-cast hypereutectic (HPDC) Al-Si alloys was investigated using a high-resolution laboratory CT and synchrotron X-ray tomography with a particular focus on the influence of HPDC microstructure. Results showed that microstructure of the alloy was mainly comprised of primary silicon particles (PSPs), Al dendrites, Cu-rich phases and pores. Most of the coarse PSPs, Cu-rich phases and pores were located in the center of the specimen. The rapid solidification of HPDC led to a heterogeneous microstructural feature. Elemental Cu was enriched in the frontiers of solid-liquid interface, causing the formation of large size dendritic arms. The pores were formed in the interdendrites which endured high stress intensity under high applied stress. Microcracks were originated from pores and further connected Cu-rich phases causing intergranular fracture. PSPs worked as obstacles causing piling-up dislocations in the phase interface. In the regions where large size of PSPs enriched in, PSPs ruptured rather than debonded from matrix, indicating transgranular fractures of PSPs. Microcracks originated around pores and PSPs tended to converge on the main cracks to decrease the energy required for crack propagation. |
| |
| Keywords: | Hypereutectic Al-Si alloy Primary silicon particles Porosity Fracture morphology High pressure die casting |
| 本文献已被 万方数据 ScienceDirect 等数据库收录！ |
|
