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Antimony Extraction from Stibnite Ore Using Alkaline Hydrometallurgical Method
, M.Sc. Thesis Sharif University of Technology ; Yoozbashizadeh, Hossein (Supervisor)
Abstract
In this research, antimony extraction by hydrometallurgical method has been investigated using an alkaline medium. Stibnite ore, as a source of antimony was leached in alkali potassium hydroxide solution. Furthermore, related kinetic equations and process factors were also studied. It was determined that optimum conditions occure when the concentration of KOH is 0.5 mol /L, the solid to liquid ratio is 100 g/L, the reaction temperature is 25 °C, and the process is performed in 115 minutes. It was found that diffusion through the ash layer controls the reaction kinetics during the first 60 minutes. Finally, for the first time, the effect of different parameters on antimony electrowinning was...
Effect of Constraint on Fracture Energy and Fracture Load Prediction of Solder Joints
, M.Sc. Thesis Sharif University of Technology ; Farrahi, Gholamhossein (Supervisor)
Abstract
Mode І critical strain energy release rate at crack initiation, Jci, of SAC305 solder joints between two copper substrates was measured using double cantilever beam (DCB) specimens at a strain rate of 0.03 s-1 as a function of bond-line width (i.e. joint size in the out-of-plane dimension), solder thickness, copper adherends thickness and suface roughness. Fracture force per unit width and Jci were relatively insensitive to width of the joint ranging from 8 to 21 mm. Variations in solder thickness (i.e. 150 µm, 250 µm and 450 µm) also had an insignificant influence on the fracture energy of solder joints. This behavior was explained in terms of stress distribution, plastic zone area and...
Influence of joint arrangement on the fracture behavior of lead-free solder joints
, Article Journal of Electronic Materials ; Volume 50, Issue 4 , 2021 , Pages 2117-2128 ; 03615235 (ISSN) ; Nourani, A ; Honarmand, M ; Assempour, A ; Sharif University of Technology
Springer
2021
Abstract
The capability to standardize the fracture strength of solder joints is an effective tool to investigate the reliability of electronic devices. To achieve this purpose, in this research, the influences of joint arrangement (loading arm and load sharing) on the level of constraint imposed on joint deformation, fracture energy, and generally, fracture behavior of solder joints were investigated. Fracture behavior of solder joints using double-cantilever-beam (DCB) specimens as a function of loading arm and load sharing (i.e., the distance between two solder joints) was studied under mode I loading conditions at a strain rate of 0.03 s−1. By increasing the loading arm, the fracture force, Fci,...
Predicting crack initiation of solder joints with varying sizes under bending
, Article Journal of Electronic Materials ; 2019 ; 03615235 (ISSN) ; Farrahi, G. H ; Nourani, A ; Soroosh, F ; Sharif University of Technology
Springer New York LLC
2019
Abstract
The critical strain energy release rate for crack initiation, J ci , was measured under mode I loading for SAC305 solder joints between two copper substrates. Fracture tests were performed using double cantilever beam specimens at a strain rate of 0.03 s −1 . Different bond-line widths (i.e., joint size in the out-of-plane dimension) and thicknesses, were examined. The fracture force per unit width and J ci (the average value of four J-integral contours encircling the crack tip) were relatively insensitive to the width of the joint ranging from 8 mm to 21 mm. Variations in bond-line thickness (i.e., 150 μm, 250 μm and 450 μm) also had an insignificant influence on the fracture energy of...
Predicting crack initiation of solder joints with varying sizes under bending
, Article Journal of Electronic Materials ; 2019 ; 03615235 (ISSN) ; Farrahi, G. H ; Nourani, A ; Soroosh, F ; Sharif University of Technology
Springer New York LLC
2019
Abstract
The critical strain energy release rate for crack initiation, J ci , was measured under mode I loading for SAC305 solder joints between two copper substrates. Fracture tests were performed using double cantilever beam specimens at a strain rate of 0.03 s −1 . Different bond-line widths (i.e., joint size in the out-of-plane dimension) and thicknesses, were examined. The fracture force per unit width and J ci (the average value of four J-integral contours encircling the crack tip) were relatively insensitive to the width of the joint ranging from 8 mm to 21 mm. Variations in bond-line thickness (i.e., 150 μm, 250 μm and 450 μm) also had an insignificant influence on the fracture energy of...