孔隙和织构均为增材制造(AM)多晶体金属的重要特征，但已有的细观力学模型无法研究2者的耦合作用对材料力学性能的影响机理。因此，本工作构建了双相金属材料的改进Mori-Tanaka (modified Mori-Tanaka，MMT)模型，在此基础上预测AM Ti-6Al-4V合金的等效弹性张量，进而探究AM 多晶体材料的微观结构对材料宏观力学性能的影响规律。本模型结合了传统MT模型和微分法，可综合分析各向异性多晶体织构和孔隙2个耦合因素与宏观力学性能的内在联系。通过有损和无损实验，研究了2种孔隙率和织构的AM Ti-6Al-4V试块的相变行为、晶粒取向分布函数、孔隙率和孔隙形貌特征。为验证理论预测的准确性，采用稀疏法与所建立模型进行对比分析；同时进行拉伸实验和超声实验，基于MMT模型得到的Young's模量与拉伸实验结果的平均绝对百分比误差(MAPE)分别为0.87%和2.51%，基于MMT模型得到的等效弹性刚度张量({\mathit{C}}^{\mathrm{e}\mathrm{f}\mathrm{f}})与超声实验结果的MAPE分别为9.47%和4.45%。可见，实验结果从力学和无损检测2个角度验证了MMT模型的有效性，为研究AM 多晶体材料的微观结构对宏观力学性能的作用机理提供了一种有效的细观力学分析方法。

Additively manufactured (AM) Ti-6Al-4V alloys are known for their lightweight and superior mechanical properties and are increasingly being favored in the aerospace, energy, and biomedical industries. Among the available AM technologies, selective laser melting (SLM) stands out for its ability to fabricate complex-shaped Ti-6Al-4V efficiently and economically through near-net-shape manufacturing. Despite their advantages, SLM-produced parts often suffer from mechanical anisotropy and contain microdefects such as pores, cracks, and residual stresses, restricting their wider application. Addressing these issues requires a thorough understanding of the effects of texture and porosity on the mechanical properties of AM materials, which is necessary for developing components that comply with strict industry standards. Previous research has predominantly focused on studying the impact of texture or porosity on material properties, overlooking the interplay between these two critical factors. This work introduces an advanced modified Mori-Tanaka (MMT) model that simultaneously considers both texture and porosity in dual-phase AM Ti-6Al-4V alloys. This model enhances the traditional Mori-Tanaka approach by integrating it with the differential method, facilitating a nuanced analysis of how texture and porosity jointly influence the mechanical behavior of polycrystals. For model development, phase transitions and grain orientations are characterized using EBSD, whereas the 3D Gaussian distribution function describes the texture distribution within the polycrystal. Micro/nano computed tomography (CT) plays a pivotal role in determining the volume fraction and morphology of pores, providing crucial data for the model. These parameters were incorporated into the mesomechanical model to analyze the effective elastic stiffness tensor and Young's modulus, quantifying their collective impact on the alloy's mechanical properties. To validate the model, tensile and ultrasonic tests are conducted for two samples with different porosities and textures and compared their outcomes to evaluate the material's mechanical behavior, which exhibits characteristics of transverse isotropy. The comparison highlights the MMT model's superior precision, especially at higher porosity levels, with mean absolute percentage errors (MAPE) between Young's modulus obtained from the MMT model and the tensile test for two samples were 0.87% and 2.51%, respectively. Similarly, the MAPE between the effective elastic stiffness tensor derived from the MMT model and the ultrasonic test were 9.47% and 4.45%, respectively. These findings underscore the model's effectiveness in predicting material properties and its potential as a robust tool for exploring the interactions between microstructural elements and macroscopic mechanical properties of AM polycrystalline materials.