Papers by Keyword: Sn

Abstract: A test probe is used for continuity test of semiconductor packages with solder balls. The probe material is often damaged due to solder adhesion on it by repeated test. The Pd-42Cu-10Ni (mass%) alloy has been developed as a substitute material for the conventional Pd-30Cu-29.5Ag-0.5Zn (mass%) alloy. The interfacial reaction between Pd-42Cu-10Ni and Sn by aging at 150°C was investigated in this study. Moreover, the obtained data was compared to those of the conventional alloy. As a result, it was confirmed that granular (Cu,Ni)₆Sn₅ forms at the interface between the reaction layer and Sn, and the reaction layer consists of stacked layers of the PdSn₄+PdSn₃ layer and the (Cu,Ni)₆Sn₅+Cu₃Sn+PdSn layer. The reaction layer mainly grew toward the Sn side from the original interface. Furthermore, the thickness of the reaction layer grown by aging was suppressed to approximately one-fourth compared with the conventional alloy.

Abstract: The accurate description of the interfacial heat transfer coefficient is of great significance for the accurate measurement of the temperature field in the process of casting cooling. In this paper, the solidification process of metallic tin in refractory mould was studied by physical simulation experiment, and the on-site temperature measurement of the mold structure was carried out. According to the temperature record, the numerical simulation method is used to realize the fitting of the calculated temperature and the measured temperature. The reversible method was used to calculate the interfacial heat transfer coefficient between the casting and the mould, and then the evolution of the internal temperature field of the casting during the cooling process was determined. The results show that the melt has a large shrinkage during the cooling process, and the interface heat transfer coefficient can reach 300 W·m^-2·K^-1, which provides a mathematical model for the annealing process of fused-cast refractories.

Abstract: In order to study the pre-straining and natural aging effects on the age-hardening response of EN AW 6082 and EN AW 6023 aluminium alloys during artificial aging at 170°C, the pre-straining by 5% was performed immediately after solution treatment of alloys at 550°C and subsequent quenching. The age-hardening response during artificial aging applied after various natural aging time (from 0.1 to 5 000 hours) was investigated using Vickers microhardness measurements and transmission electron microscopy characterization. It was found that pre-straining of quenched alloys state caused a dislocation density increasing in solid solution, which resulted in an immediate microhardness increase of alloys. During the subsequent natural aging of EN AW 6082 alloy, its microhardness increased right after alloy quenching and pre-straining, but only to the values obtained for the unstrained alloy state. On the contrary, the hardness of pre-straining EN AW 6023 alloy that is alloyed by Sn did not increase either after 10 hours of natural aging. This phenomenon is attributed to the effect of Sn on suppression of the strengthening clusters formation. The hardness of alloys increased greatly during artificial aging after pre-straining and natural aging due to accelerating the formation of coherent β″-phase particles. The negative effect of natural aging on the maximum age-hardening response obtained during alloys artificial aging had been observed for most of the pre-strained and naturally aged alloys states, with exception of EN AW 6023 alloy states that were pre-strained and shortly naturally aged (up to 100 hours).

Abstract: Magnesium alloys have the characteristic with high specific strength and lightweight property, it is widely used for auto mobile industry. Heat-resistant magnesium alloy is focused as a suitable material for weight reduction of the engine and power train parts in automotive field. In this study, microstructure and heat-resistant property in Mg-3mass%Al-1mass%Si (Mg-3%Al-1%Si) alloy with containing large amount of Sn (tin) were investigated. The alloys produced by permanent mold casting were investigated by optical microscope (OM), scanning electron microscopy (SEM) and measuring of bolt load retention at 423K. The heat-resistant property of Mg-3mass % Al-1mass % Si alloy with containing 6-13masss%Sn was higher compared with Sn free alloy and conventional Magnesium alloys (e.g. AZ91 and AM60 alloys).

Abstract: The pyrometallurgical method of tin extraction from lead free solder dross after leaching treatment is discussed. The solder dross is sieved into 75 μm was used for the experiment. The samples were leached using 0.3 M HCl, 12 hours stirring times and temperature of 60°C was used for the leaching before thermal treatment. The sample was thermally treated at temperature of 650,850 and 1050°C. The increase of heating temperature causes the lowering of the tin extraction. The optimum parameter for heating temperature is 850°C with 98.71% of tin recovery.

Abstract: Tin doped zinc oxide (Sn:ZnO) thin films were prepared on glass substrates via sol-gel dip-coating technique starting from zinc acetate dehydrate, (CH₃CO₂)₂Zn⋅2H₂O and tin chloride, SnCl₂. The consequences of various Sn doping on the behavior of the film was investigated. The atomic percentages of dopant in ZnO-based solution were [Sn⁴⁺]/[Zn²⁺] which is between 0% and 4%. The thin films were characterized using Field Emission Scanning Electron Microscope (FESEM) and UV-Vis-NIR spectrophotometer.

Abstract: This project deals with the experimental results of leaching of Sn from solder dross by means of leaching using different concentration of hydrochloric acid (HCl). Solder dross was sieved to obtain a mean particle size of 75 μm. The solder dross powder obtained was leached by using HCl acid aqueous solution. To optimize the parameter required for recovery of Sn from solder dross, initially the bench scale studies were carried out using varying acid concentration, stirring time and temperature. The experimental indicate that 98.7% of Sn was leached out from solder dross using 0.1M of HCl, 24 hours of stirring time at60°C solution temperature.

Abstract: A first-principle simulation of the surface diffusion of an extra metal (Me) adatom on the corresponding 1/3 monolayer (ML) Ge (111)√3×√3 Me induced surfaces has been performed. Using the Nudged Elastic Band (NEB) optimization method, the minimum energy paths and activation energy barrier profiles for all known Me inducing √3×√3 reconstruction on a Ge(111) surface have been obtained. The value of the activation barrier is shown to depend on the adatom formation energies and the atomic radius of the diffusing metal: 0.33 eV for Pb and 0.25 eV for Sn. The Arrhenius pre-exponential factors that were obtained in the harmonic approximation are as large as 10^11-12 Hz for all of the investigated surfaces, which supports the single-atomic diffusion model considered here.

Abstract: The microstructure and mechanical properties of magnesium alloy AZ61wtih1% Sn addition has been studied in this paper. The results show that the addition of 1% Sn can refine the grain size and improve the microstructure morphology of β-Mg₁₇Al₁₂ phase. The addition of Sn can cause the formation of Mg₂Sn phase in AZ61 alloy, which can effectively enhance the mechanical properties of magnesium alloy AZ61 at room temperature and 150°C.

Abstract: To develop a new low-temperature crystallization technique, annealing characteristics of a-GeSn/Si (100) structures are investigated. It is revealed that epitaxial growth accompanying Si-Ge mixing is generated at temperatures in the liquid-solid coexisting region of the Ge-Sn system. The annealing temperature necessary for epitaxial growth is significantly decreased by increasing annealing time and/or Sn concentration. Consequently, epitaxial growth at 300°C becomes possible. These findings are expected to be useful to realize next-generation large-scale integrated circuits, where various multi-functional devices are integrated.