摘要
Near-αtitanium alloy and Ti_(2)AlNb alloy powders premixed with different proportions were prepared on the near-αtitanium alloy substrate by laser deposition technique,and the microstructure characteristics were analyzed and discussed.Results show that numerous river-like sub-grain structures are formed inside the equiaxed B2 grains of the laser-deposited premixed titanium alloy powders with the proportion of Ti_(2)AlNb above 40wt%,whereas the needle-like structure within coarse columnarβgrains exist with the proportion of Ti_(2)AlNb below 40wt%.It is noteworthy that the decrease in laser power and scanning speed can accelerate the formation of sub-grain structures.Based on the analysis of experimental results,it can be inferred that the formation of sub-grain structure not only is related to the precipitation of O phase due to composition micro-segregation at sub-grain boundaries,but also is inseparable from the stacking faults caused by the internal stress during the laser deposition.
通过激光沉积在近α钛合金基板上制备了不同比例的预混合近α钛合金和Ti_(2)AlNb合金粉末,并对2种粉末的微观组织演变和结构特征进行了分析和讨论。结果表明,Ti_(2)AlNb含量在40%(质量分数,下同)以上的激光沉积预混合钛合金粉末的等轴B2晶粒内形成了许多河流状亚晶粒结构,而Ti_(2)AlNb含量在40%以下的粗柱状β晶粒内则呈现针状结构。值得注意的是,降低激光功率和扫描速度可以促进亚晶粒结构的形成。基于实验结果的分析可以推断出,这种亚晶粒结构的形成不仅与亚晶界成分微偏析导致的O相析出有关,还与激光沉积过程中内应力诱导的堆垛层错密不可分。
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2024年第12期3281-3290,共10页
Rare Metal Materials and Engineering
基金
National Natural Science Foundation of China(51974259)
Xi'an Municipal Bureau of Science and Technology(21ZCZZHXJS-QCY6-0008)
Industry-Academic Cooperation Project of Aero Engine Corporation of China(HFZL2020CXY021)。
