Effects of K 2 SiF 6 on Ignition and Heat Release Characteristic of Nano-Sized Aluminum Powders

ABSTRACTThis study investigates the effect of potassium fluosilicate (K2SiF6) on the ignition and heat release characteristics of n-Al50, n-Al100, and n-Al800. It is found that K2SiF6 can effectively improve the ignition and heat release characteristics of nano-aluminum powder (n-Al). This is because K2SiF6 effectively increases the reaction rate. The heat release characteristics of the n-Al/K2SiF6 mixture are improved as the particle size of aluminum powder decreases and the heating rate increases. However, when the particle size reaches a certain level, the enhancement effect will become smaller and smaller. The study revealed that the addition of K2SiF6 influences the ignition delay time, reaction, and combustion products of the n-Al/K2SiF6 mixture. A small amount of K2SiF6 can greatly reduce the ignition delay time of nano-aluminum powder. With the increase of K2SiF6 content, the ignition delay time of n-Al50 decreases first and then increases, while the ignition delay time of n-Al100 and n-Al800 decreases continuously but the extent of this reduction progressively diminishes. The morphology and composition of the combustion products were analyzed. This paper found that K2SiF6 fluorinates the oxidized shell of aluminum, thereby promoting its ignition and combustion. The influence mechanism of K2SiF6 on n-Al ignition in air is discussed.KEYWORDS: Combustion phenomenaignitionpotassium fluosilicatenano aluminumthermogravimetric analysisView correction statement:Correction AcknowledgementsThis work is supported by the National Key R&D Program of China (2021YFF0601004).Disclosure statementThe authors declared that they have no conflicts of interest to this work.Additional informationFundingThis work was supported by the National Key Research and Development Program of China [2021YFF0601004].