搅拌摩擦加工制备NiTip/WE43镁基复合材料

Preparation of NiTip/WE43 magnesium matrix composites by friction stir processing

摘要:

本研究提供了一种采用搅拌摩擦加工（FSP）制备NiTi颗粒增强WE43镁基复合材料的有效手段。采用SEM结合EDS对FSP试样的微观结构进行了研究，采用XRD进行了物相分析。结果表明，制备的复合材料具有形状记忆效应。较低的加工温度有效地阻止了NiTi颗粒与Mg基体在FSP过程中的界面反应。无论粒径大小，在FSP后，NiTi颗粒都均匀分布在Mg基体中。此外，与Mg基体相比，NiTi/WE43复合材料的屈服强度、极限拉伸强度和延伸率分别降低了33%、12%和18%。随着加入的NiTi颗粒尺寸的增大，该复合材料拉伸强度和延伸率均降低。复合材料的失效机理是颗粒之间的界面开裂以及增强颗粒的断裂。

Abstract:

This study provided an effective technique of friction stir processing (FSP) to fabricate the NiTi particle reinforced WE43 magnesium (Mg) matrix composite. The microstructures of FSP specimens were examined by scanning electron microscopy (SEM) coupled with an energy-dispersive X-ray spectroscope (EDS). X-ray diffraction (XRD) was used for phase analysis. The results showed that the composite possessed the shape memory effect. The low processing temperature effectively prevented the interfacial reaction between the NiTi particles and Mg matrix during FSP. Regardless of particle size, the NiTi particles were homogeneously distributed in the Mg matrix. In addition, compared with the Mg matrix, the yield strength, ultimate tensile strength, and elongation of the NiTip/WE43 composite were reduced by 33%, 12%, and 18%, respectively. Both the tensile strength and elongation were decreased with increasing the size of as-received NiTi particles. The failure mechanism of the composite was interface debonding and the fracture of reinforced particles.