The effect of particle deformation zone (PDZ) on the microstructure and mechanical properties of SiC_p/Mg-5Zn composites was studied. Meanwhile, the work hardening and softening behavior of SiC_p/Mg-5Zn composites influenced by PDZ size were analyzed and discussed using neutron diffraction under in-situ tensile deformation. The evolution of FWHM (full width at half maximum) extracted from the diffraction pattern of SiC_p/Mg-5Zn composites was used to interpret the modification of dislocation density during in-situ tension, which discovered the effect of dislocation on the work hardening behavior of SiC_p/Mg-5Zn composites. In addition, the tensile stress reduction (ΔP_i) values during in-situ tension test were calculated to analyze the effect of PDZ size on the softening behavior of SiC_p/Mg-5Zn composites. The results show that the work hardening rate of SiC_p/Mg-5Zn composites increased with the enlargement of PDZ size, which was attributed to the grain size of SiC_p/Mg-5Zn composites increased with the enlargement of PDZ size. Moreover, the stress reduction (ΔP_i) values increased continuously during in-situ tensile for SiC_p/Mg-5Zn composites due to the increased stored energy produced during plastic deformation, which provided a driving force for the softening effect. However, the effect of grain size on the softening behavior is greater than that of the stored energy, which led to the tensile stress reduction (ΔP_i) values of P30 (d_PDZ = 30 μm) -SiC_p/Mg-5Zn composite were higher than that of P60 (d_PDZ = 60 μm) -SiC_p/Mg-5Zn composite when the ε_ri were 0.25, 0.5, 0.75 and 1, respectively.

研究了颗粒变形区（PDZ）对SiC _p / Mg-5Zn复合材料的组织和力学性能的影响。同时，利用中子衍射在原位拉伸变形条件下，分析和讨论了受PDZ尺寸影响的SiC _p / Mg-5Zn复合材料的工作硬化和软化行为。从SiC _p / Mg-5Zn复合材料的衍射图谱提取的FWHM（半峰全宽）的演变用于解释原位拉伸过程中位错密度的变化，从而发现位错对加工硬化行为的影响SiC _p / Mg-5Zn复合材料的制备。另外，拉伸应力降低（ΔP计算原位拉伸试验的_i）值，以分析PDZ尺寸对SiC _p / Mg-5Zn复合材料软化行为的影响。结果表明，随着PDZ尺寸的增大，SiC _p / Mg-5Zn复合材料的加工硬化速率增加，这归因于随着PDZ尺寸的增大，SiC _p / Mg-5Zn复合材料的晶粒尺寸增大。此外，应力减小（ ΔP_我）值连续地增加期间在原位拉伸用于SiC _p/ Mg-5Zn复合材料由于在塑性变形过程中产生的增加的储能，从而为软化效果提供了驱动力。然而，晶粒尺寸对软化行为的效果比所存储的能量，而导致的拉伸应力减小的（大于ΔP_我）P30（的值d _PDZ = 30微米）-SiC _p / Mg的复合5Zn分别比P60（高d _PDZ = 60微米）-SiC _p / Mg的复合5Zn当ε _RI分别为0.25，0.5，分别为0.75和1，。