Crystallization of CoWB ternary boride in nickel-based metallic glass

•Crystallization kinetics of CoWB ternary boride in Ni-based metallic glass were investigated for the first time.•The continuous heating transformation diagram for CoWB precipitation were plotted by calculations using Kissinger approach.•The melt crystallization and glass crystallization behaviors of the Ni-Co-W-B alloy are different from each other.•It has been shown that the Ni-WCoB composite is stable up to 1150 K without forming a third phase. The crystallization kinetics of CoWB ternary boride were investigated through non-isothermal differential scanning calorimetry experiments, using a Ni-based metallic glass precursor as the starting material. The effects of isothermal heat treatment temperature on the phase evolutions were also systematically studied. The results showed that the melt crystallization and glass crystallization behaviors of the alloy differ from each other. The continuous heating transformation diagram plotted from non-isothermal analyses is consistent with the results of isothermal heat treatments. A broad ternary boride precipitation zone was demonstrated, involving the gradual precipitation of CoWB crystals. Avrami exponent values for the early crystallization stage showed that the crystallization mechanism of CoWB is governed by the interface-controlled three-dimensional growth mechanism, and nucleation rate is high. As the crystallization progresses, a diffusion-controlled growth occurs and the nucleation rate decreases. This study offers insights into the heat treatment of CoWB-reinforced nickel matrix nanocomposites, benefiting future research and industrial production processes.