论文部分内容阅读
研究半固态TiB2增强Al-Mg合金复合材料浆料的流变性能,对半固态加工过程中的充型模拟是必需的。在一台Searle型流变仪的加热室内,将TiB2增强原位Al-Mg合金复合材料样品再熔化,随后将温度降低到半固态温度范围。为了复合材料的流变性能,进行三种不同的实验:稳态实验、连续冷却实验和等温实验。此外,从实验得到的滞回曲线证实了浆料的触变性。结果表明:当等温保持时,复合材料浆料显示假塑性和剪切变稀行为直到剪切速率达到1300 s-1;在更高剪切速率(>1300 s-1)下,它显示出剪切增稠趋势,这可能是由于不可变形的纳米TiB2颗粒的团聚引起的。通过剪切速率的间歇阶跃变化(剪切突变实验)也证实了浆料的假塑性行为。
Studying the rheological properties of semi-solid TiB2 reinforced Al-Mg alloy composite slurry is necessary for filling simulation in semi-solid processing. In a Searle Rheometer heating chamber, the TiB2 reinforced in-situ Al-Mg alloy composite sample was remelted and the temperature was subsequently reduced to a semi-solid temperature range. For the rheological properties of the composite material, three different experiments were performed: steady-state experiment, continuous cooling experiment and isothermal experiment. In addition, the hysteretic curve obtained from the experiment confirms the thixotropy of the slurry. The results show that the pseudoplasticity and shear thinning behavior of the composite slurry at isothermal hold until the shear rate reaches 1300 s-1; at higher shear rates (> 1300 s-1), it shows shear The trend of thickening is probably due to the agglomeration of non-deformable nano-TiB2 particles. The pseudoplastic behavior of the pastes was also confirmed by intermittent step changes in shear rate (shear mutagenesis experiments).