Abstract
TiB2 particles with different contents were in situ synthesized in liquid Al62.5Sn28.7Cu8.8 monotectic alloy. The nucleation, growth, and migration mechanisms of the secondary liquid L2(Sn) phase during liquid phase separation were investigated by experimental observations and theoretical analyses. When 1% TiB2 particles were added to this ternary monotectic alloy, macrosegregation induced by liquid phase separation was significantly reduced, whereas, when TiB2 content was further increased, there was only a little enhancement in the reduction of macrosegregation degree. Meanwhile, the secondary (Sn) phase and primary θ(Al2Cu) phase structures were refined after TiB2 particles were incorporated into the alloy melt. During liquid phase separation, the in situ synthesized TiB2 particles promoted the heterogeneous nucleation of the secondary L2(Sn) phase, resulting in the formation of a large number of L2(Sn) droplets. In addition, TiB2 particles restricted the diffusion growth of L2(Sn) droplets by impeding element diffusion and droplet migration, and hindered Stokes sedimentation of L2(Sn) droplets by changing the viscosity and density of the alloy melt as well as the droplet shape. The tensile property of monotectic Al62.5Sn28.7Cu8.8 alloy was improved as TiB2 content increased.
Translated title of the contribution | Phase separation mechanism of liquid Al62.5Sn28.7Cu8.8 monotectic alloy modulated by in situ synthesized TiB2 particles |
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Original language | Chinese (Traditional) |
Pages (from-to) | 1679-1691 |
Number of pages | 13 |
Journal | Zhongguo Kexue Jishu Kexue/Scientia Sinica Technologica |
Volume | 52 |
Issue number | 11 |
DOIs | |
State | Published - 2022 |