Effect of Gd on microstructure and refinement performance of Al-5Ti-B alloy  

作　　者：Dong-song Yin Ning Zhang Ke-ju Chen Yun-long Zhang 

机构地区：[1]School of Materials Science and Engineering,Heilongjiang University of Science and Technology,Haerbin 150022,China [2]School of Materials Science and Engineering,Jiamusi University,Jiamusi 154007,China

出　　处：《China Foundry》2021年第3期223-228,共6页中国铸造（英文版）

摘　　要：Al-5Ti-B and Al-5Ti-B-Gd master alloy refiners were fabricated by fluorine salt casting method.The microstructure and phase constitution of the master alloys were investigated by scanning electron microscopy (SEM),transmission electron microscopy (TEM) and X-ray diffraction (XRD).The results show that Al-Ti-B alloy refiner consists of Al_(3)Ti phase and TiB2 phase.After Gd is introduced into the intermediate alloy,Ti_(2)Al_(20)Gd phase appears in the alloy,the size of Al_(3)Ti is significantly reduced,and Ti-Al-Gd phase is found in the edge of Al_(3)Ti phase.At the same time,some independent Ti-Al-Gd phases appear in local areas,which are Ti_(2)Al_(20)Gd phase determined by micro-area electron diffraction analysis.Analysis and calculation results of the high-resolution images of the Ti_(2)Al_(20)Gd/Al structure show that there is no other compound at the junction between the Ti_(2)Al_(20)Gd phase and Al,and Ti_(2)Al_(20)Gd phase has a great difference in atomic space with the α-Al,which cannot be directly used as heterogeneous nucleus.But,after being decomposed in the aluminum melt,the Ti_(2)Al_(20)Gd phase can promote the refinement effect of the refiner.In the Al-Ti-B-Gd master alloy,there are many dispersed Al_(3)Ti particles with a size of less than 1 μm,which can promote the Al-5Ti-B refining effect.

关 键 词：Al-5Ti-B alloy refiner Al_(3)Ti rare earth Gd Ti_(2)Al_(20)Gd 

分 类 号：TG146.21[一般工业技术—材料科学与工程]