Both the microgravity solidification mechanism and resultant micromechanical properties of ternary Ni₄₁Fe₄₀Ti₁₉ alloy were investigated by means of drop tube, nanoindentation, and nano-dynamic mechanical analysis (Nano-DMA) techniques. The microstructure of the Ni₄₁Fe₄₀Ti₁₉ alloy droplets consisted of γ-(Fe,Ni) dendrites and interdendritic pseudobinary eutectic phases. The average cooling rate and undercooling increased significantly as the droplet diameter decreased during free fall. Owing to the refinement of the rapidly solidified microstructure, and the Ti solute hardening of the primary γ-(Fe,Ni) dendrites, the microhardness of this alloy was remarkably increased with the decrease of droplet size. Moreover, the nanohardness of the γ-(Fe,Ni) dendrite increased as the indentation displacement decreased within the depth range of 40 to 244 nm, indicating a conspicuous indentation size effect (ISE). However, the ISE increased as the undercooling increased, because additional geometrically necessary dislocations (GNDs) were required, while intragranular dislocation motion was further hindered as the Ti content increased. The size effect factor increased linearly with the reduced droplet diameter.

通过滴管，纳米压痕和纳米动态力学分析（Nano-DMA）技术研究了Ni ₄₁ Fe ₄₀ Ti ₁₉三元合金的微重力凝固机理和所得的微机械性能。Ni ₄₁ Fe ₄₀ Ti ₁₉合金微滴的微观结构由γ-（Fe，Ni）树枝状晶体和树枝状准二元共晶相组成。随着自由下落过程中液滴直径的减小，平均冷却速度和过冷度显着增加。由于快速凝固的组织的细化和一次γ的Ti溶质硬化-（Fe，Ni）树枝状结晶，随着液滴尺寸的减小，该合金的显微硬度显着提高。此外，随着压痕位移在40至244 nm的深度范围内减小，γ-（Fe，Ni）枝晶的纳米硬度增加，表明压痕尺寸效应（ISE）明显。但是，ISE随过冷度的增加而增加，这是因为需要额外的几何上必需的位错（GND），而随着Ti含量的增加，晶内位错运动会进一步受到阻碍。尺寸影响因子随着液滴直径的减小而线性增加。