The effects of Ce on the secondary dendrite arm spacing（SDAS） and mechanical behavior of Al-Si-Cu-Mg alloys were investigated. The reduction of SDAS at different Ce concentrations was evaluated in a directional soli...The effects of Ce on the secondary dendrite arm spacing（SDAS） and mechanical behavior of Al-Si-Cu-Mg alloys were investigated. The reduction of SDAS at different Ce concentrations was evaluated in a directional solidification experiment via computer-aided cooling curve thermal analysis（CA-CCTA）. The results showed that 0.1wt%-1.0wt% Ce addition resulted in a rapid solidification time, ？ts, and low solidification temperature, ？T_S, whereas 0.1wt% Ce resulted in a fast solidification time, Δ^（ta-Al）, of the α-Al phase. Furthermore, Ce addition refined the SDAS, which was reduced to approximately 36%. The mechanical properties of the alloys with and without Ce were investigated using tensile and hardness tests. The quality index（Q） and ultimate tensile strength of（UTS） Al-Si-Cu-Mg alloys significantly improved with the addition of 0.1wt% Ce. Moreover, the base alloy hardness was improved with increasing Ce concentration.展开更多
The influence of praseodymium(Pr) content on the solidification characteristics, microstructure, and mechanical properties of ZRE1 magnesium(Mg) cast alloy was investigated. The obtained solidification parameters show...The influence of praseodymium(Pr) content on the solidification characteristics, microstructure, and mechanical properties of ZRE1 magnesium(Mg) cast alloy was investigated. The obtained solidification parameters showed that Pr strongly affected the solidification time, leading to refinement of the microstructure of the alloys. When the freezing time was reduced to approximately 52 s, the grain size decreased by 12%. Mg_(12)Zn(Ce,Pr) was formed as a new phase upon the addition of Pr and was detected via X-ray diffraction analysis. The addition of Pr led to a substantial improvement in mechanical properties, which was attributed to the formation of intermetallic compounds; the ultimate tensile strength and yield strength increased by approximately 10% and 13%, respectively. Pr addition also refined the microstructure, and the hardness was recovered. The results herein demonstrate that the mechanical properties of Mg alloys are strongly influenced by their microstructure characteristics, including the grain size, volume fraction, and distribution of intermetallic phases.展开更多
基金the ministry of higher education Malaysia and Universiti Tun Hussein Onn Malaysia for supporting this research under Vot no FRGS1422 and E15501
文摘The effects of Ce on the secondary dendrite arm spacing（SDAS） and mechanical behavior of Al-Si-Cu-Mg alloys were investigated. The reduction of SDAS at different Ce concentrations was evaluated in a directional solidification experiment via computer-aided cooling curve thermal analysis（CA-CCTA）. The results showed that 0.1wt%-1.0wt% Ce addition resulted in a rapid solidification time, ？ts, and low solidification temperature, ？T_S, whereas 0.1wt% Ce resulted in a fast solidification time, Δ^（ta-Al）, of the α-Al phase. Furthermore, Ce addition refined the SDAS, which was reduced to approximately 36%. The mechanical properties of the alloys with and without Ce were investigated using tensile and hardness tests. The quality index（Q） and ultimate tensile strength of（UTS） Al-Si-Cu-Mg alloys significantly improved with the addition of 0.1wt% Ce. Moreover, the base alloy hardness was improved with increasing Ce concentration.
文摘The influence of praseodymium(Pr) content on the solidification characteristics, microstructure, and mechanical properties of ZRE1 magnesium(Mg) cast alloy was investigated. The obtained solidification parameters showed that Pr strongly affected the solidification time, leading to refinement of the microstructure of the alloys. When the freezing time was reduced to approximately 52 s, the grain size decreased by 12%. Mg_(12)Zn(Ce,Pr) was formed as a new phase upon the addition of Pr and was detected via X-ray diffraction analysis. The addition of Pr led to a substantial improvement in mechanical properties, which was attributed to the formation of intermetallic compounds; the ultimate tensile strength and yield strength increased by approximately 10% and 13%, respectively. Pr addition also refined the microstructure, and the hardness was recovered. The results herein demonstrate that the mechanical properties of Mg alloys are strongly influenced by their microstructure characteristics, including the grain size, volume fraction, and distribution of intermetallic phases.
