The Oxidation and Combustion Properties of Gas Atomized Aluminum−Boron−Europium Alloy Powders

Abstract

AbstractIn this paper, the Aluminum−boron−europium ternary alloy fuels with boron content of 1.5∼4.85 wt. % and europium content of 3 wt. % were prepared by the close‐coupled gas atomization. XRD, SEM, TG‐DTA and oxygen bomb test were used to analyze the phase constituents, morphology, thermal oxidation behavior and combustion exothermic property of powders, respectively. The functions of boron and europium on the combustion of metal fuels were studied, and a reasonable oxidation model of the alloy particles was proposed. The results show that there are Al, AlB2, Al4Eu and B6Eu in the alloy. When the europium content is constant, the combustion enthalpy of the Al−B−Eu alloy powder firstly increases and then decreases as the boron content increases. Additionally, at oxygen pressure of 3.0 MPa, the Al−3.5B−3Eu ternary alloy powder burned completely with the maximum combustion enthalpy of 33324.5 J g−1. This increases by 11 % compared with theoretical combustion enthalpy of aluminum powder (31.1 kJ g−1). Al−3.5B−3Eu undergoes a dramatic oxidation exothermal phenomenon at 1110 °C with the weight increase efficiency of 53.66 %, which is 1.7 times that of aluminum. Due to the synergistic effects between the phase of B6Eu and AlB2 inside the alloy particles, the Al−3.5B−3Eu alloy powder shows excellent exothermic performance.