發(fā)布時(shí)間：2018-02-26 09:03

  本文關(guān)鍵詞： 半固態(tài)攪拌 納米Si C顆粒 鎂基復(fù)合材料 微觀組織 力學(xué)性能　出處：《鑄造技術(shù)》2016年05期 　論文類型：期刊論文

【摘要】：采用半固態(tài)機(jī)械攪拌鑄造法,制備了增強(qiáng)體平均粒徑50 nm的Si C顆粒增強(qiáng)鎂基復(fù)合材料(n-Si Cp/Mg9Al),分別對(duì)不同質(zhì)量分?jǐn)?shù)納米顆粒、不同攪拌時(shí)間和不同攪拌溫度時(shí),復(fù)合材料的微觀組織和力學(xué)性能進(jìn)行了研究。結(jié)果表明,隨著Si C含量的增加,合金基體組織先細(xì)化后又出現(xiàn)變粗的現(xiàn)象,適當(dāng)延長攪拌時(shí)間能更有效地細(xì)化組織,在較低溫度下攪拌可以更明顯地細(xì)化復(fù)合材料的微觀組織。合金抗拉強(qiáng)度隨著Si C含量的增加先增加后降低,在Si C含量為1.5%時(shí)最好,為198 MPa。在含量為2%時(shí)又有所降低,但是高于不加Si C時(shí)。攪拌時(shí)間為15 min時(shí),復(fù)合材料的屈服強(qiáng)度、抗拉強(qiáng)度較之基體分別提高了12.8%、22%,斷后伸長率由基體合金的2%提升到4%。繼續(xù)延長攪拌時(shí)間到30 min,材料的室溫拉伸性能出現(xiàn)明顯惡化。不同攪拌溫度下Si Cp/Mg9Al納米復(fù)合材料與鑄態(tài)Mg9Al合金相比其室溫拉伸性能有明顯提高,攪拌溫度為600℃的Si Cp/Mg9Al納米復(fù)合材料的室溫拉伸性能最好,其屈服強(qiáng)度、抗拉強(qiáng)度和斷后伸長率分別為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，

本文編號(hào)：1537360