Gleeble experiments concerning dendrite re-melting and its role in microstructural evolution in spray formed high-alloy metals

An experimental approach was designed to understand dendrite fragmentation of atomized droplets deposition in spray materials, and to study the relationship between dendrite fragmentation behavior and subsequent microstructural evolution. A Gleeble 3500 physical simulator was used to create controlled thermal shock conditions in solid-liquid mixtures of Superalloy GH4169 and High Speed Steel (HSS) T15 atomised powders, which simulated the environment of droplet deposition during the spray forming of large diameter billets at Beijing Institute of Aeronautical Materials (BIAM). The experiment results support that the rapid remelting and thermal shock play an important role in the development of the fine equiaxed microstructure in spray forming high-alloy metals.