Effect of carbon on the ignition and combustion characteristics of amorphous boron particles

Carbon is the main component of a combustion products of boron. It has important influence to secondary ignition combustion.The influence of different contents of carbon on the ignition and combustion characteristics of boron particles was studied by thermogravimetry (TG) and differential scanning calorimetry (DSC), X-ray diffractometer (XRD) and laser ignition test system. The mass contents of carbon in the mixture of boron and carbon samples were set to be 0%, 10%, 20%, 50% and 100%. Results indicate that the addition of carbon make the sample weight gain lower during the process of heating. The influence of the mass content of carbon on the heating process is complex. When the content of carbon is low, the oxidation reaction delays and the heat release increases, while as it increases, the results turn to be opposite. Under oxygen atmosphere, with an increase in the mass content of carbon, the maximum combustion peak intensity of the sample decreases, the burning time of the sample is prolonged from 2436 ms to 2909 ms, but the ignition delay of carbon to the sample is less, not more than 3 ms.The combustion products are black massive solid, which mainly consist of boron oxide and carbon, etc.The analysis of the combustion products of the sample shows that the ignition combustion reaction of the sample is not sufficient.