Nyamannavar, S.Ravi, M.Prabhu, K.N.2020-03-302020-03-30200868th World Foundry Congress 2008, WFC 2008, 2008, Vol., , pp.559-562https://idr.nitk.ac.in/handle/123456789/7541Isothermal holding of an alloy at semi-solid temperature and quenching/cooling, results in formation of instabilities on the globuletic ?-particles. The aspect of instability formation is necessary input for accurate simulation and modeling of microstructure evolution for semi-solid metal forming (SSM) process. In the present work instability formation is studied for Al-7Si-0.3Mg alloy. Small cylindrical samples (10 mm, height 10 mm) were subjected to isothermal holding at semisolid temperature followed by quenching/cooling to room temperature. Instabilities were found to form at cooling rates 30 and 100 K/s. Instability formation is explained by interface stabilization theory based on the constitutional undercooling of liquid ahead of the solid/liquid interface.Book chapter