Study on the Precipitation Sequence of Aged NCu30-4-2-1 Alloy by DSC
NCu30-4-2-1 alloy was handled by solid solution at 950°Cfor 2h and then taking aging treatment at different temperatures and holding time. The microstructural evolution of NCu30-4-2-1 alloy in the process of aging treatment was investigated by metallographic microscope, X-ray diffractometer and differential scanning calorimetry. The results show that the phases of as-cast NCu30-4-2-1 alloy is composed by dendritic α-Ni-based solid solution and β-Ni3Si. After solid solution and aging treatment, the block distribution β-Ni3Si dissolves and many small granular dispersed distribution β'-Ni3Si precipitate out. With the increase of aging temperature and holding time, metastable β' tends to transform into stable β-Ni3Si. The precipitation sequence of aged NCu30-4-2-1alloy is supersaturated solid solution of α-Ni, GP zone, β'-Ni3Si and β-Ni3Si.