2AlNb合金粉末，并對2種粉末的微觀組織演變和結構特征進行了分析和討論。結果表明，Ti2AlNb含量在40%（質(zhì)量分數(shù)，下同）以上的激光沉積預混合鈦合金粉末的等軸B2晶粒內(nèi)形成了許多河流狀亞晶粒結構，而Ti2AlNb含量在40%以下的粗柱狀β晶粒內(nèi)則呈現(xiàn)針狀結構。值得注意的是，降低激光功率和掃描速度可以促進亞晶粒結構的形成?；趯嶒灲Y果的分析可以推斷出，這種亞晶粒結構的形成不僅與亞晶界成分微偏析導致的O相析出有關，還與激光沉積過程中內(nèi)應力誘導的堆垛層錯密不可分。;Near-α titanium alloy and Ti2AlNb alloy powders premixed with different proportions were prepared on the near-α titanium 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 Ti2AlNb above 40wt%, whereas the needle-like structure within coarse columnar β grains exist with the proportion of Ti2AlNb 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."/>