高能球磨对Mg-Zn-Zr合金微观组织与力学性能的影响

发布时间：2018-04-28 15:12

本文选题：镁合金粉末 + 高能球磨　；参考：《材料导报》2017年18期

【摘要】：在氩气条件下以400r/min高能球磨镁合金粉末,并将球磨后的粉末经过冷压—热压烧结—热挤压成型。研究了不同球磨时间的粉末以及挤压态样品的微观组织和力学性能。结果表明:随着球磨时间的延长,粉末颗粒尺寸可以细化到8μm,晶粒尺寸有效细化到34nm,在整个球磨过程中粉末有一定程度的氧化,并伴随有MgO纳米颗粒产生。粉末经过热压烧结—热挤压成型后,材料内部有MgZn2相颗粒析出,且均匀分布于Mg基体中。随着粉末颗粒的细化,材料性能得到改善,当球磨至10h时,粉末挤压态样品的极限拉伸强度为365 MPa,压缩屈服强度高达325 MPa,极限压缩强度保持在466 MPa。球磨至25h,颗粒平均尺寸细化至8μm左右,使得颗粒表面能大幅度增大,颗粒表面的氧化膜增厚,在热压烧结过程中阻碍了颗粒之间的结合,进而使得材料的力学性能恶化。
[Abstract]:Under the condition of argon gas, the powder of magnesium alloy was milled with 400r/min high energy, and the powder after ball milling was formed by cold pressing hot pressing and hot extrusion. The microstructure and mechanical properties of powder and extruded sample were studied at different ball milling time. The results showed that the size of powder particles could be refined to 8 mu m with the prolongation of ball milling time. The particle size is effectively refined to 34nm, and the powder has a certain degree of oxidation during the whole ball milling process, accompanied by the production of MgO nanoparticles. After hot pressing and hot extrusion, the powder has MgZn2 phase particles in the material and evenly distributed in the Mg matrix. With the refinement of the powder particles, the properties of the materials are improved, when the ball is milled to 10h. The ultimate tensile strength of the powder extruded sample is 365 MPa, the compressive yield strength is up to 325 MPa, the ultimate compressive strength is kept at 466 MPa. to 25h, the average size of the particles is refined to 8 mu m, which makes the particle surface increase greatly, the oxide film on the particle surface thickens, and hinders the bonding between the particles during the hot pressing process. Furthermore, the mechanical properties of the material are deteriorated.

【作者单位】：青海大学青海省高性能轻金属合金及深加工工程技术研究中心青海省新型轻合金重点实验室;
【基金】：国家自然科学基金(51661028) 青海省科技厅基础研究项目(2015-ZJ-736)
【分类号】：TG146.22

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