Effect of yttrium on microstructure and mold filling capacity of a near-α high temperature titanium alloy

作     者：Zhao Ertuan Chen Yuyong Kong Fantao Zhang Changjiang Xiao Shulong 

作者机构：National Key Laboratory for Precision Hot Processing of MetalsHarbin Institute of TechnologyHarbin 150001China 

出 版 物：《China Foundry》 (中国铸造（英文版）)

年 卷 期：2012年第9卷第4期

页      面：344-348页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

主　　题：high temperature titanium alloy yttrium mold filling capacity investment casting 

摘      要：The addition of rare earth yttrium(Y) can improve the performances of high temperature titanium alloys,such as the tensile ductility,thermal stability and creep property,***,few studies on the effect of Y on the castability of titanium alloys have been carried out,which is significant to fabrication of thin-walled complex titanium castings by investment *** this study,the microstructure and mold filling capacity of a Ti-1100 alloy with different Y additions(0,0.1wt.%,0.3wt.%,0.5wt.% and 1.0wt.%) were investigated systematically through investment casting experiments,and the casting experiments were carried out in a centrifugal titanium casting *** microstructures of the alloy were observed via the optical microscopy,scanning electron microscopy and transmission electron *** mold filling capacity was tested by using of a grid pattern and was evaluated by the number of segments completely filled by the cast *** results indicate that the grain size is decreased and the mold filling capacity is improved significantly with increasing the addition of Y from 0 to 1.0wt.%.The average primary grain size of Ti-1100 alloy is reduced from 250 μm to 50 μm and the mold filling capacity is increased from 61.5% to 100%.Considering the potential harmful effect on tensile properties of titanium alloys due to high concentrations of Y,it is suggested that Y addition should be about 0.3wt.%.