Impact of Thermal Aging on the Microstructure Evolution and Mechanical Properties of Lanthanum-Doped Tin-Silver-Copper Lead-Free Solders
Article dans une revue avec comité de lecture
Date
2013Journal
Journal of Electronic MaterialsAbstract
An extensive study is made to analyze the impact of pure lanthanum on the microstructure and mechanical properties of Sn-Ag-Cu (SAC) alloys at high temperatures. Different compositions are tested; the temperature applied for the isothermal aging is 150 C, and aging times of 10 h, 25 h, 50 h, 100 h, and 200 h are studied. Optical microscopy with cross-polarized light is used to follow the grain size, which is refined from 8 mm to 1 mm for as-cast samples and is maintained during thermal aging. Intermetallic compounds (IMCs) present inside the bulk Sn matrix affect the mechanical properties of the SAC alloys. Due to high-temperature exposure, these IMCs grow and hence their impact on mechanical properties becomes more significant. This growth is followed by scanning electron microscopy, and energy-dispersive spectroscopy is used for elemental mapping of each phase. A significant refinement in the average size of IMCs of up to 40% is identified for the as-cast samples, and the coarsening rate of these IMCs is slowed by up to 70% with no change in the interparticle spacing. Yield stress and tensile strength are determined through tensile testing at 20 C for as-cast samples and after thermal aging at 150 C for 100 h and 200h. Both yield stress and tensile strength are increased by up to 20% by minute lanthanum doping.
Files in this item
Related items
Showing items related by title, author, creator and subject.
-
Article dans une revue avec comité de lectureAn original approach is proposed to predict the behavior of the16MND5bainitic steel (similar to U.S. A508 cl.3) in the lower range of the ductile-to-brittle transition region and at lower temperatures [−196 ◦C; 20 ◦C], by ...
-
Article dans une revue avec comité de lectureGZYL, Michal; ROSOCHOWSKI, Andrzej; BOCZKAL, Sonia; OLEJNIK, Lech; PESCI, Raphaël (Springer Verlag, 2015)The influence of twinning on the strain hardening rate and fracture mechanism in AZ31B magnesium alloy was studied in this work by in situ microstructural analysis during tensile testing in a chamber of scanning electron ...
-
Article dans une revue avec comité de lectureRUSINEK, Alexis; RODRIGUEZ-MARTINEZ, José A.; CAPELLE, Julien; PESCI, Raphaël (Polish Society of theoretical and applied Mechanics, 2010)In this investigation, thermo-viscoplastic behaviour of austenitic steel AISI 304 has been characterised in tension under wide ranges of strain rate at room temperature. This metal possesses an elevated strain hardening ...
-
Conférence invitéeINAL, Karim; MASSON, Renaud; PESCI, Raphaël (Jacques Besson, Dominique Moinereau, Dirk Steglich, 2006)A series of in-situ tensile tests was performed at various low temperatures to characterize the mechanical properties and the fracture processes of the 16MND5 steel: the damage was observed with a SEM and the internal ...
-
Conférence invitéeZAERA, Ramon; CASADO, Alvaro; RODRIGUEZ-MARTINEZ, José Antonio; RUSINEK, Alexis; FERNANDEZ-SAEZ, José; PESCI, Raphaël (2011)This work presents a constitutive model for metastable austenitic steels exhibiting Strain Induced Martensitic Transformation (SIMT). Based on the description of the kinetics of phase transformation proposed by Olson and ...