The role of the rare earth element Sm in as-cast Zn-5AI alloy was studied in this work.A three times higher improvement than the control group on corrosion resistance was found with rare earth Sm adding(0.15 wt%).By u...The role of the rare earth element Sm in as-cast Zn-5AI alloy was studied in this work.A three times higher improvement than the control group on corrosion resistance was found with rare earth Sm adding(0.15 wt%).By using an electron prove micro analyzer(EPMA),focused ion beam(FIB)and scanning Kelvin probe force microscopy(SKPFM)techniques,two main mechanisms of the premium performance of the Sm adding were revealed.One was that the non-uniform nucleation and component undercooling induced by Sm adding,reduced theα-AI layer spacing thus improved the covering efficiency of the Al_(2)O_(3)film.The other was that the dissolved Sm in the Zn/Al eutectic structure modulated the electron work function thus induced the attenuation of Volta potential discrepancy.The experimental results show that when the addition of Sm is 0.15 wt%,the minimum Volta potential difference betweenα-AI andη-Zn phases is achieved,and excessive or deficient Sm addition will increase the Volta potential difference.展开更多
Ultrasonic-assisted soldering of 2024 aluminum alloys using a filler metal of Zn-5Al alloy was investigated at the temperature of 400 ℃,which is lower than the solution strengthening temperature of Al-Cu alloys.The u...Ultrasonic-assisted soldering of 2024 aluminum alloys using a filler metal of Zn-5Al alloy was investigated at the temperature of 400 ℃,which is lower than the solution strengthening temperature of Al-Cu alloys.The ultrasonic vibration with power of 200 W and vibration amplitude of 15 μm at the frequency of 21 kHz was applied on the top samples.The ultrasonic vibration promoted the dissolution of Al elements in the base metal.The reduction of volume fraction of the eutectic phases in the bonds was investigated by increasing ultrasonic vibration time.As the ultrasonic vibration time increased from 3 s to 30 s,the volume fraction of the eutectic phase in the bonds decreased from 12.9% to 0.9%,and the shear strength of the joints was up to 149-153 MPa,increased by 20%.The improvement of the mechanical properties of joints was discussed based on the modulus and hardness of the phases in the bonds and the fracture of the joints.展开更多
研究了生物医用Zn-5Al合金的微观组织结构演化,探讨了其组织对力学性能的影响.对铸态、均匀化处理和轧制态Zn-5Al合金的微观组织进行了表征,分析了合金的相组成,测试了轧制态Zn-5Al合金的力学性能.结果表明:铸态与均匀化处理后的Zn-5Al...研究了生物医用Zn-5Al合金的微观组织结构演化,探讨了其组织对力学性能的影响.对铸态、均匀化处理和轧制态Zn-5Al合金的微观组织进行了表征,分析了合金的相组成,测试了轧制态Zn-5Al合金的力学性能.结果表明:铸态与均匀化处理后的Zn-5Al合金的相组成均主要为η-Zn相和α-Al相,铸态合金组织片层间距约为300 nm.均匀化处理过程中发生了共析反应,合金中的α-Al相由铸态的长条形演变为球形共晶组织.经过总变形率85%的热轧变形后,Zn-5Al合金的屈服强度和抗拉强度分别为98 MPa和130 M Pa,断裂延伸率达到74%.展开更多
基金the National Natural Science Foundation of China(51974097,52161010)Central Government Guides Local Science and Technology Development Special Projects(20194011)+1 种基金the Program of"One Hundred Talented People"of Guizhou Province(20164014)Guizhou Province Science and Technology Project(20175656,20175788,20191414,20192162)。
文摘The role of the rare earth element Sm in as-cast Zn-5AI alloy was studied in this work.A three times higher improvement than the control group on corrosion resistance was found with rare earth Sm adding(0.15 wt%).By using an electron prove micro analyzer(EPMA),focused ion beam(FIB)and scanning Kelvin probe force microscopy(SKPFM)techniques,two main mechanisms of the premium performance of the Sm adding were revealed.One was that the non-uniform nucleation and component undercooling induced by Sm adding,reduced theα-AI layer spacing thus improved the covering efficiency of the Al_(2)O_(3)film.The other was that the dissolved Sm in the Zn/Al eutectic structure modulated the electron work function thus induced the attenuation of Volta potential discrepancy.The experimental results show that when the addition of Sm is 0.15 wt%,the minimum Volta potential difference betweenα-AI andη-Zn phases is achieved,and excessive or deficient Sm addition will increase the Volta potential difference.
基金Projects(51075104,50975054) supported by the National Natural Science Foundation of ChinaProject(2010RFQXG020) supported by the Harbin Excellence Talents Program,China
文摘Ultrasonic-assisted soldering of 2024 aluminum alloys using a filler metal of Zn-5Al alloy was investigated at the temperature of 400 ℃,which is lower than the solution strengthening temperature of Al-Cu alloys.The ultrasonic vibration with power of 200 W and vibration amplitude of 15 μm at the frequency of 21 kHz was applied on the top samples.The ultrasonic vibration promoted the dissolution of Al elements in the base metal.The reduction of volume fraction of the eutectic phases in the bonds was investigated by increasing ultrasonic vibration time.As the ultrasonic vibration time increased from 3 s to 30 s,the volume fraction of the eutectic phase in the bonds decreased from 12.9% to 0.9%,and the shear strength of the joints was up to 149-153 MPa,increased by 20%.The improvement of the mechanical properties of joints was discussed based on the modulus and hardness of the phases in the bonds and the fracture of the joints.
文摘研究了生物医用Zn-5Al合金的微观组织结构演化,探讨了其组织对力学性能的影响.对铸态、均匀化处理和轧制态Zn-5Al合金的微观组织进行了表征,分析了合金的相组成,测试了轧制态Zn-5Al合金的力学性能.结果表明:铸态与均匀化处理后的Zn-5Al合金的相组成均主要为η-Zn相和α-Al相,铸态合金组织片层间距约为300 nm.均匀化处理过程中发生了共析反应,合金中的α-Al相由铸态的长条形演变为球形共晶组织.经过总变形率85%的热轧变形后,Zn-5Al合金的屈服强度和抗拉强度分别为98 MPa和130 M Pa,断裂延伸率达到74%.
