ABSTRACT

Aluminum powders are well known for excellent release of energy during oxidation upon heating. However, this release of energy becomes limited due to formation of dense oxide (Al₂O₃) layer on powder surface. In this study, reactivity of aluminum particles was improved by replacing oxide layer with metallic shell of iron using electroless plating technique. Three different bath compositions were selected for deposition of iron on aluminum particles. The surface morphology of prepared Al/Fe core–shell composite powder was characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Further, iron content in the composite powder was measured quantitatively using helium gas pycnometer while elemental analysis was performed by X-ray diffraction (XRD). Finally, thermo-physical behavior of the composite powder was investigated using simultaneous thermogravimetry–differential scanning calorimetry (TG–DSC). The results showed that the synthesized Al/Fe core–shell composite powder exhibits higher energy release in comparison to the uncoated aluminum powder upon heating in air (up to 1180 °C). The powder with the densest iron coating released the highest energy.

摘要

众所周知，铝粉在加热氧化过程中能出色地释放能量。然而，由于形成致密的氧化物（Al ₂ O ₃) 粉末表面上的层。在这项研究中，通过使用化学镀技术用铁的金属壳代替氧化物层来提高铝颗粒的反应性。选择了三种不同的浴组合物用于在铝颗粒上沉积铁。通过扫描电子显微镜（SEM）和能量色散X射线光谱（EDX）对制备的Al/Fe核壳复合粉末的表面形貌进行表征。此外，使用氦气比重计定量测量复合粉末中的铁含量，同时通过X射线衍射(XRD)进行元素分析。最后，使用同步热重-差示扫描量热法（TG-DSC）研究了复合粉末的热物理行为。结果表明，与未涂覆的铝粉相比，合成的铝/铁核壳复合粉末在空气中加热（最高 1180 ℃）表现出更高的能量释放。具有最致密铁涂层的粉末释放的能量最高。