Al⁃LiH复合燃料制备及性能

Preparation and Performance of Al⁃LiH Composite Fuel

为了提高铝粉燃烧效率,利用球磨法分别制备了质量含量为3%,5%,10%,15%的Al‐LiH复合燃料。通过X射线衍射仪(XRD)、扫描电镜(SEM)、粒度仪对样品结构、形貌和粒径进行表征;采用差热‐热重量热仪对其热氧化性能进行表征,最后采用CO_(2)激光点火装置、高速摄像机及氧弹量热仪对其燃烧性能进行考察。结果表明:通过球磨法可以将LiH嵌入Al粉内部,LiH含量是影响其微观形貌及粒径、粒径分布的关键因素,LiH的加入使得燃料质量热值增加,同时随着LiH含量的增加Al‐LiH复合燃料燃烧火焰强度增强,点火延迟时间大幅降低。其中由于Al‐LiH复合燃料在高温下发生了微爆现象,Al‐3LiH和Al‐10LiH复合燃料在一次氧化后分别实现第二次氧化。

To improve the combustion efficiency of aluminum powders,Al‐LiH composite fuels with mass contents of 3%,5%,10%,and 15%were prepared using the ball milling method,respectively.The sample structure,morphology,and particle size are characterized by X‐ray diffraction(XRD),scanning electron microscopy(SEM),and particle size analyzer.The thermal oxidation performance was characterized using the DSC‐TG.Finally,their combustion performance was investigated using the CO_(2)laser ignition device,high‐speed camera,and oxygen bomb calorimeter.The results show that LiH can be embedded into Al powder through the ball milling method,and the LiH content is a key factor affecting its microstructure,particle size,and particle size distribution.The addition of LiH increases the mass calorific value of fuel.At the same time,with the increase of LiH content,the combustion flame intensity of Al‐LiH composite fuel increases and the ignition delay time significantly decreases.Among them,Al‐3LiH and Al‐10LiH composite fuels achieve second oxidation after the first oxidation.The analysis suggests that the second oxidation phenomenon is caused by the microexplosion phenomenon of Al‐LiH composite fuel at high temperatures.