Structure and thermal behavior of lead-free solders prepared by rapid solidification of their melt

2017 ◽  
Vol 29 (1) ◽  
pp. 49-53 ◽  
Author(s):  
Martin Durisin ◽  
Alena Pietrikova ◽  
Juraj Durisin ◽  
Karel Saksl

Purpose The paper aims to investigate the structure and thermal stability of newly developed lead-free Sn-based alloys which can be used as novel materials in the soldering of electronic components. Design/methodology/approach Rapid solidification was used to prepare the alloys. Findings The results showed that the microstructure of these solders exhibited uniform distribution and small-sized intermetallic compounds. Also, smaller crystalline size can be expected compared to commercially available counterparts. The analyses revealed a uniform and homogenous distribution of the small intermetallic particles of Cu6Sn5 and Ag4Sn in the microstructure of solders. The practical implications mean an improvement in mechanical properties and thermal stability of such solder joints, which is a precondition of low mechanical, thermo-mechanical stresses in their structure. Originality/value The originality lies in the production of these alloys by the melt spinning technique which was not previously used in the electronics industry.

2000 ◽  
Vol 644 ◽  
Author(s):  
Martin Hollmark ◽  
Victor Tkatch ◽  
Sergey Khartsev ◽  
Alex Grishin

AbstractA glassy structure was formed in the Fe40Co40P14B6 alloy by melt-spinning technique. The as-quenched 2-8 mm wide and 15-30 [.proportional]m thick ribbons exhibit good soft magnetic properties: the saturation magnetization of 1.45 T, the coercive force of 4 A/m and maximum differential permeability at 60 Hz of about 90000. The FeCo-based glass crystallizes via eutectic reaction into a mixture of an austenite and a b.c. tetragonal Fe3P-like phase similar to that of the well-known Fe40Ni40P14B6metallic glass, but at temperatures about 60 K higher than the latter. The evaluation of the thermodynamic and kinetic parameters of crystallization process brought us to the conclusion that the improved thermal stability of the Fe40Co40P14B6 glass is caused by the enhanced interfacial nucleus-glass energy.


2018 ◽  
Vol 24 (3) ◽  
pp. 223 ◽  
Author(s):  
Andrea Školáková ◽  
Petra Hanusová ◽  
Filip Průša ◽  
Pavel Salvetr ◽  
Pavel Novák ◽  
...  

<p>In this work, Al-11Fe, Al-7Fe-4Ni and Al-7Fe-4Cr (in wt. %) alloys were prepared by combination of casting and hot extrusion. Microstructures of as-cast alloys were composed of aluminium matrix with large and coarse intermetallics such as Al<sub>13</sub>Fe<sub>4</sub>, Al<sub>13</sub>Cr<sub>2</sub> and Al<sub>5</sub>Cr. Subsequently, as-cast alloys were rapidly solidified by melt-spinning technique which led to the supersaturation of solid solution alloying elements. These rapidly solidified ribbons were milled and compacted by hot-extrusion method. Hot-extrusion caused that microstructures of all alloys were fine with uniform dispersed particles. Moreover, long-term thermal stability was tested at temperature 300 °C for as-cast and hot-extruded alloys and chromium was found to be the most suitable element for alloying to improve thermal stability.    </p>


1996 ◽  
Vol 455 ◽  
Author(s):  
J. J. Suñol ◽  
M. T. Clavaguera-Mora ◽  
N. Clavaguera ◽  
T. Pradell

ABSTRACTMechanical alloying and rapid solidification are two important routes to obtain glassy alloys. New Fe-Ni based metal-metalloid (P-Si) alloys prepared by these two different processing routes were studied by differential scanning calorimetry and transmission Mössbauer spectroscopy. Mechanical alloyed samples were prepared with elemental precursors, and different nominal compositions. Rapidly solidified alloys were obtained by melt-spinning. The structural analyses show that, independent of the composition, the materials obtained by mechanical alloying are not completely disordered whereas fully amorphous alloys were obtained by rapid solidification. Consequently, the thermal stability of mechanically alloyed samples is lower than that of the analogous material prepared by rapid solidification. The P/Si ratio controls the magnetic interaction of the glassy ribbons obtained by rapid solidification. The experimental results are discussed in terms of the degree of amorphization and crystallization versus processing route and P/Si ratio content.


2015 ◽  
Vol 3 (34) ◽  
pp. 8780-8787 ◽  
Author(s):  
Jin-Song Zhou ◽  
Ke Wang ◽  
Fang-Zhou Yao ◽  
Ting Zheng ◽  
Jiagang Wu ◽  
...  

Multi-scale thermal stability of (K,Na)NbO3-based perovskites with a high d33 of 430 pC N−1 is investigated, revealing the origin of its large piezoelectricity.


2020 ◽  
Vol 32 (3) ◽  
pp. 181-187
Author(s):  
Mohammad Gharaibeh

Purpose This paper aims to investigate the fatigue life performance of SAC305 ball grid array solders under combined temperature and harmonic vibration loading conditions. Design/methodology/approach Fatigue tests were performed using a sine dwell with resonance tracking vibration and temperature loading experiment. Finite element stress analysis was also performed to help in understanding the observed failure trends. Findings Fatigue test results showed that the lead-free solders tend to fail quickly in higher temperatures and higher vibration loading test conditions. The failure analysis results revealed that in low temperatures, the solder cracks are initiated and propagated at the package side. However, in high temperatures, the cracks are observed at the board side of the interconnect. In all conditions, the cracks are propagated throughout the intermetallic compound layer. Originality/value In the published literature, there is a lack of data in the area of fatigue assessment of lead-free solders under combined temperature and vibration loadings. This paper provides useful insights into combined thermal/vibration fatigue, i.e. reliability behavior of lead-free solder joint types.


2017 ◽  
Vol 69 (6) ◽  
pp. 1049-1065 ◽  
Author(s):  
Zhe Liu ◽  
Wei Chen ◽  
Desheng Li ◽  
Wenjing Zhang

Purpose In high-speed processing, the influence on the machining accuracy of a machine tool is greatly caused by the thermal deformation of the motorized spindle; a further study on the thermal characteristics of the spindle is given in this paper. This study aims to reduce the thermal error and improve the performance of the machine tool by discussing the relationships between the temperature distributions and rotating accuracy caused by the thermal deformations of the spindle. Design/methodology/approach The paper opted for a method combining the theoretical analysis and the experimental study to study the thermal stability of the high-speed motorized spindle. First of all, a finite element model of the spindle was built with ANSYS, whereby temperature distributions and the thermal deformations were successively obtained at different speeds. And then, both the temperature field and the rotating accuracy of the motorized spindle were measured simultaneously by the thermal stability experiment. Finally, the experimental and theoretical results were compared and validated. Findings The thermal stability of the motorized spindle was studied in this paper, and some findings from the study were as follows: the spindle’s rotating accuracy maintained good in X direction but bad in Y and Z directions in terms of the deformations; the higher front-end temperature of the spindle which can significantly affect the rotating accuracy is needed to be controlled mainly; the recovery speed of the spindle deformation lagged behind the temperature’s fallback speed; the vibration graph about radial rotating sensitivity synthesized by X1 and X2 presented a trifoliate shape. Originality/value Based on a built test-bed which can synchronously measure the motorized spindle’s temperature distribution and rotating accuracy with five-point method, the coupling effects of the thermal deformation and temperature are embodied, and not only the vibration graph but also the thermal tilt angles can be gained. Therefore, considering the influence of the thermal deformation on the heat generated by the bearings, the paper fulfilled a study by which it was obtained that the front-end temperature of the spindle, which was higher and could significantly affect the rotating accuracy, needed to be controlled mainly.


2014 ◽  
Vol 216 ◽  
pp. 35-38 ◽  
Author(s):  
Cosmin Codrean ◽  
Dragoş Buzdugan ◽  
Ramona Lǎzar ◽  
Viorel Aurel Şerban ◽  
Ion Mitelea

Ni based amorphous alloys with Si and B, which can also, contains Fe and Cr, prepared by rapid solidification, have low melting temperatures. This fact increases their susceptibility to be joined by welding and brazing. The glass forming ability (GFA) is conditioned also by the crystallization delay, due to certain chemical composition of the alloys. The thermal stability of these alloys was revealed by DTA analysis and structural characteristics were investigated by XRD. Applying an annealing at temperatures between 420°C and 540°C, with 30 minutes maintaining time, allowed the investigation of phase occurred during the crystallization and the estimation of the crystalline grains dimensions.


2017 ◽  
Vol 68 ◽  
pp. 152-158 ◽  
Author(s):  
L. Dimesso ◽  
C. Fasel ◽  
K. Lakus-Wollny ◽  
T. Mayer ◽  
W. Jaegermann

Sign in / Sign up

Export Citation Format

Share Document