Papers by Keyword: Eutectic Melting

Abstract: In the present study, thermal treatments for homogenizing cast structures of Al-Cu-Li alloy AA2195 for improved workability are developed chiefly by empirical methods and detailed Differential Scanning Calorimetry (DSC) and microstructural characterization. DSC has been carried out on as-cast samples to establish the homogenization temperatures and avoid incipient melting. Homogenization time has been calculated empirically and microstructural characterization and DSC has been carriedout to after each cycle to validate the empirically established homogenization cycle. Homogenization cycle (435°C/8hrs+495°C/12hrs+525°C/32hrs) has been established for AA2195 alloy having an average grain size of 500μm based on calorimetric studies and microstructural examination.

Abstract: We investigated the method of joining silicon nitride having on its surface a thin layer of active silicon metal to carbon steel. The active silicon layer is formed through the thermal dissociation of silicon nitride (Si3N4) into silicon (Si) and nitrogen gas (N2). The active silicon layer is directly joined to carbon steel via an induced eutectic melting reaction between the silicon and iron (Fe) found in carbon steel, or via brazing of two materials using general brazing metal such as Ag-Cu alloys. This joining process does not require the use of expensive active brazing alloys such as Ag-Cu-Ti alloys or a sputtering method designed to coat the active metals on surface of silicon nitride.