纳米SiC颗粒增强镁基复合材料半固态搅拌法制备工艺优化

发布时间：2018-02-26 09:03

  本文关键词： 半固态搅拌 纳米Si C颗粒 镁基复合材料 微观组织 力学性能　出处：《铸造技术》2016年05期 　论文类型：期刊论文

【摘要】：采用半固态机械搅拌铸造法,制备了增强体平均粒径50 nm的Si C颗粒增强镁基复合材料(n-Si Cp/Mg9Al),分别对不同质量分数纳米颗粒、不同搅拌时间和不同搅拌温度时,复合材料的微观组织和力学性能进行了研究。结果表明,随着Si C含量的增加,合金基体组织先细化后又出现变粗的现象,适当延长搅拌时间能更有效地细化组织,在较低温度下搅拌可以更明显地细化复合材料的微观组织。合金抗拉强度随着Si C含量的增加先增加后降低,在Si C含量为1.5%时最好,为198 MPa。在含量为2%时又有所降低,但是高于不加Si C时。搅拌时间为15 min时,复合材料的屈服强度、抗拉强度较之基体分别提高了12.8%、22%,断后伸长率由基体合金的2%提升到4%。继续延长搅拌时间到30 min,材料的室温拉伸性能出现明显恶化。不同搅拌温度下Si Cp/Mg9Al纳米复合材料与铸态Mg9Al合金相比其室温拉伸性能有明显提高,搅拌温度为600℃的Si Cp/Mg9Al纳米复合材料的室温拉伸性能最好,其屈服强度、抗拉强度和断后伸长率分别为106 MPa、155 MPa和4%。
[Abstract]:Si-C particle reinforced magnesium matrix composites with average particle size of 50 nm were prepared by semi-solid mechanical stirring casting. The results showed that the nano-particles with different mass fraction, different stirring time and different stirring temperature were prepared. The microstructure and mechanical properties of the composites were studied. The results showed that with the increase of Si C content, the microstructure of alloy matrix was refined first and then thickened, and the microstructure could be refined more effectively by prolonging the stirring time. The microstructure of the composite can be refined more obviously by stirring at lower temperature. The tensile strength of the alloy increases first and then decreases with the increase of Si C content, which is the best when the Si C content is 1.5 MPA. However, when the stirring time is 15 min, the yield strength of the composite is higher than that without sic. Compared with the matrix, tensile strength increased by 12.822 and the elongation after breaking increased from 2% to 40.The room temperature tensile properties of the composites deteriorated obviously when the stirring time was prolonged to 30 mins. At different stirring temperatures, the tensile properties of Si Cp/Mg9Al nanocomposites were obviously deteriorated. Compared with the as-cast Mg9Al alloy, the tensile properties of the alloy at room temperature are obviously improved. The room temperature tensile properties of Si Cp/Mg9Al nanocomposites with stirring temperature of 600 鈩，

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