Effect of the Annealing Temperature and Constant Magnetic Field on the Decomposition of Quenched Beryllium Bronze BrB-2

The effect of the annealing temperature and of a constant magnetic field on decomposition of quenched beryllium bronze BrB-2 is studied by scanning electron microscopy for the first time. A technical bronze alloy BRB-2 is kept at a temperature of 800°C for 0.5 h, quenched in water, and subjected to artificial aging at 325, 350, and 400°C for 1 h under a constant magnetic field of 0.7 T and without it. The decomposition of the alloy proceeds simultaneously by several mechanisms, including a discontinuous (cellular) decomposition. For the first time, a specific decomposition mechanism is reported near the triple junctions and near the grain boundaries. The activation barriers for discontinuous decomposition near the triple junctions in a constant magnetic field decrease, the growth rates noticeably increase, and the size of cells decreases almost twofold. The microstructure data are compared with the results of the microhardness and X-ray diffraction measurements. A possible mechanism of the impact of a constant magnetic field on the discontinuous decomposition in copper-based alloys is discussed.