Microstructures and mechanical properties of Sn–8.55Zn–0.45Al–XAg solders

2003 ◽  
Vol 18 (7) ◽  
pp. 1528-1534 ◽  
Author(s):  
Chia-Wei Huang ◽  
Kwang-Lung Lin
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Tensile Strength ◽  
Melting Point ◽  
Eutectic Temperature ◽  
Lead Free ◽  
Eutectic Solder ◽  
Microstructures And Mechanical Properties ◽  
Lead Free Solders

The microstructure, melting point, and mechanical properties of Sn–8.55Zn–0.45Al–XAg lead-free solders were investigated. The Ag content of the solders investigated was 0–3 wt.%. The results indicate that the AgZn3 and Ag5Zn8 compounds are formed at the addition of Ag to Sn–8.55Zn–0.45Al solders. The adding of Ag also results in the formation of hypoeutectic structure, increasing the melting point of the solders and decreasing the ductility. Results of thermal analysis reveal that the Sn–8.55Zn–0.45Al–XAg solder has eutectic temperature at 198 °C when the addition of Ag is 0.5 wt.%. The eutectic solder exhibits greater tensile strength and higher ductility than the 63–Sn–37Pb solder.

Effect of aluminum content on structure, transport and mechanical properties of Sn-Zn eutectic lead free solder alloy rapidly solidified from melt.

2015 ◽  
Vol 10 (1) ◽  
pp. 2641-2648
Author(s):  
Rizk Mostafa Shalaby ◽  
Mohamed Munther ◽  
Abu-Bakr Al-Bidawi ◽  
Mustafa Kamal
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Lead Free ◽  
Al Alloy ◽  
Lead Free Solder ◽  
Pronounced Increase ◽  
Mass Unit ◽  
Size Refinement ◽  
Free Solder ◽  
Lead Free Solders

The greatest advantage of Sn-Zn eutectic is its low melting point (198 oC) which is close to the melting point. of Sn-Pb eutectic solder (183 oC), as well as its low price per mass unit compared with Sn-Ag and Sn-Ag-Cu solders. In this paper, the effect of 0.0, 1.0, 2.0, 3.0, 4.0, and 5.0 wt. % Al as ternary additions on melting temperature, microstructure, microhardness and mechanical properties of the Sn-9Zn lead-free solders were investigated. It is shown that the alloying additions of Al at 4 wt. % to the Sn-Zn binary system lead to lower of the melting point to 195.72 ˚C.  From x-ray diffraction analysis, an aluminium phase, designated α-Al is detected for 4 and 5 wt. % Al compositions. The formation of an aluminium phase causes a pronounced increase in the electrical resistivity and microhardness. The ternary Sn-9Zn-2 wt.%Al exhibits micro hardness superior to Sn-9Zn binary alloy. The better Vickers hardness and melting points of the ternary alloy is attributed to solid solution effect, grain size refinement and precipitation of Al and Zn in the Sn matrix.  The Sn-9%Zn-4%Al alloy is a lead-free solder designed for possible drop-in replacement of Pb-Sn solders.  

scholarly journals The microstructure and properties of as-cast Sn-Zn-Bi solder alloys

2012 ◽  
Vol 66 (4) ◽  
pp. 595-600 ◽  
Author(s):  
Srba Mladenovic ◽  
Desimir Markovic ◽  
Ljubica Ivanic ◽  
Svetlana Ivanov ◽  
Zagorka Acimovic-Pavlovic
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ternary Alloys ◽  
Hazardous Substances ◽  
Lead Free ◽  
Solder Alloys ◽  
Rich Phase ◽  
Soldering Temperature ◽  
The Matrix ◽  
Lead Free Solders

Research on the lead-free solders has attracted wide attention, mostly as the result of the implementation of the Directive on the Restriction of the Use of Hazardous Substances in Electrical and Electronic Equipment. The Sn-Zn solder alloys have been considered to be one of the most attractive lead-free solders due to its ability to easily replace Sn-Pb eutectic alloy without increasing the soldering temperature. Furthermore, the mechanical properties are comparable or even superior to those of Sn-Pb solder. However, other problems still persist. The solution to overcoming these drawbacks is to add a small amount of alloying elements (Bi, Ag, Cr, Cu, and Sb) to the Sn-Zn alloys. Microstructure, tensile strength, and hardness of the selected Sn-Zn-Bi ternary alloys have been investigated in this study. The SEM-EDS was used for the identification of co-existing phases in the samples. The specimens? microstructures are composed of three phases: Sn-rich solid solution as the matrix, Bi-phase and Zn-rich phase. The Bi precipitates are formed around the Sn-dendrit grains as well as around the Zn-rich phase. The amount of Bi segregation increases with the increase of Bi content. The Sn-Zn-Bi alloys exhibit the high tensile strength and hardness, but the values of these mechanical properties decrease with the increase of Bi content, as well as the reduction of Zn content. The results presented in this paper may offer further knowledge of the effects various parameters have on the properties of lead-free Sn-Zn-Bi solders.

The Effects of Small Additions Ga and Al on the Microstructure and Tensile Properties of Sn-Zn Based Lead-Free Solders

2013 ◽  
Vol 800 ◽  
pp. 265-270 ◽  
Author(s):  
Kang I Chen ◽  
Shou Chang Cheng ◽  
Chin Hsiang Cheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Melting Temperature ◽  
Eutectic Structure ◽  
Lead Free ◽  
Microstructures And Mechanical Properties ◽  
Lead Free Solders

The melting temperature, microstructures, and mechanical properties of the Sn-Zn-0.5Ag-0.5Ga, Sn-Zn-0.5Ag-0.45Al and Sn-Zn-0.5Ga-0.45Al lead-free solders were investigated. The results indicate that the addition of 0.5 wt% Ag to the Sn-Zn based alloys destroy the eutectic structure and results in the formation of Ag-Zn compound and hypoeutectic structure. The variation in the microstructure lowers the UTS. By the addition of Al the UTS and elongation of the 0.5Ag-0.45Al alloy can be decreased due to the Al diffused to the interface of the Ag-Zn compound/Sn-Zn eutectic structure to form Al-Zn compound. The 0.5Ga-0.45Al alloy shows a typical eutectic structure with the light contract β-Sn and the darker needle-like phase, as well as a small amount of Al-Zn phase with a near diamond shape. Gallium uniformly distributes in the Sn matrix and Zn rich phases. The 0.5Ga-0.45Al solder had the highest UTS and elongation, while 0.5Ag-0.45Al had the lowest UTS and elongation. The results indicate that Ga and Al exhibits prominent influence on the microstructure as well as the mechanical properties of the solders.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

Mechanical properties of QFP micro-joints soldered with lead-free solders using diode laser soldering technology

2008 ◽  
Vol 18 (4) ◽  
pp. 814-818 ◽  
Author(s):  
Zong-jie HAN ◽  
Song-bai XUE ◽  
Jian-xin WANG ◽  
Xin ZHANG ◽  
Liang ZHANG ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Diode Laser ◽  
Lead Free ◽  
Soldering Technology ◽  
Laser Soldering ◽  
Lead Free Solders

Dependence of Microstructures and Mechanical Properties on the Growth Rate and Composition in Directionally Solidified Mg-Gd Alloys

2022 ◽  
Vol 327 ◽  
pp. 82-97
Author(s):  
He Qin ◽  
Guang Yu Yang ◽  
Shi Feng Luo ◽  
Tong Bai ◽  
Wan Qi Jie
Keyword(s):  
Mechanical Properties ◽  
Growth Rate ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Dendritic Structure ◽  
Directionally Solidified ◽  
Dendrite Morphology ◽  
Microstructural Parameters ◽  
Wide Range ◽  
Microstructures And Mechanical Properties

Microstructures and mechanical properties of directionally solidified Mg-xGd (5.21, 7.96 and 9.58 wt.%) alloys were investigated at a wide range of growth rates (V = 10-200 μm/s) under the constant temperature gradient (G = 30 K/mm). The results showed that when the growth rate was 10 μm/s, different interface morphologies were observed in three tested alloys: cellular morphology for Mg-5.21Gd alloy, a mixed morphology of cellular structure and dendritic structure for Mg-7.96Gd alloy and dendrite morphology for Mg-9.58Gd alloy, respectively. Upon further increasing the growth rate, only dendrite morphology was exhibited in all experimental alloys. The microstructural parameters (λ1, λ2) decreased with increasing the growth rate for all the experimental alloy, and the measured λ1 and λ2 values were in good agreement with Trivedi model and Kattamis-Flemings model, respectively. Vickers hardness and the ultimate tensile strength increased with the increase of the growth rate and Gd content, while the elongation decreased gradually. Furthermore, the relationships between the hardness, ultimate tensile strength, the growth rate and the microstructural parameters were discussed and compared with the previous experimental results.

Study on the Lead-Free Easy-Cutting Mg-Sb Brass

2011 ◽  
Vol 239-242 ◽  
pp. 1670-1673 ◽  
Author(s):  
Lei Li ◽  
Biao Ma ◽  
Qiang Li ◽  
Guo Jie Huang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Grain Boundaries ◽  
Human Health ◽  
Hot Working ◽  
Experimental Results ◽  
Lead Free ◽  
Environment Friendly ◽  
Working Property ◽  
Pipe Joint

Traditional lead brass is gradually prevented from application by many countries’ governments because lead does harm to human health and pollutes the environment. New types of environment-friendly lead-free brass with favorable machinability are urgently demanded in the electrical, electronics and plumping fields. Lead-free Mg-Sb brass was fabricated in present. Experimental results showed that when the content of Mg is 1.0wt%, Sb is 0.8wt% and Cu is 58.0~59.0wt%, the alloy’s mechanical properties and machinability are favorable for industry application. With the increase of the content of Sb, the machinability increased, while the mechanical properties decreased. Lots of Cu2Mg and Cu9Sb2 particles on the order of microns exist in the inner-grain and grain boundaries. These particles improve the machinability, however, lower the tensile strength and the elongation. A three-way pipe joint was successfully punched with the fabricated Mg-Sb brass bar, and this demonstrated that the fabricated Mg-Sb brass possesses favorable hot working property.

Effect of Zr on the microstructures and mechanical properties of as-extruded Mg–2.3Zn–0.18Y–xZr alloys

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744001 ◽  
Author(s):  
Yufan Wang ◽  
Yingbo Zhang ◽  
Wei Gao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Aging Treatment ◽  
Grain Refining ◽  
Maximum Increase ◽  
Microstructures And Mechanical Properties ◽  
Average Size ◽  
Precipitate Strengthening ◽  
Zr Alloys

The microstructures and mechanical properties of as-extruded Mg–2.3Zn–0.18Y–[Formula: see text]Zr ([Formula: see text] = 0.03, 0.06 and 0.13 at.%) alloys and aged Mg–2.3Zn–0.18Y–0.13Zr alloy were studied. The results revealed that the microstructures of as-extruded Mg–2.3Zn–0.18Y–[Formula: see text]Zr alloys are typical bimodal structures. The coarse [Formula: see text]-Mg grains are surrounded by fine dynamically recrystallized [Formula: see text]-Mg grains. The average size of [Formula: see text]-Mg grains decreases with increasing Zr content. Moreover, the addition of Zr (at.%) can improve the mechanical properties of alloy. The as-extruded Mg–2.3Zn–0.18Y–0.13Zr alloy has the best mechanical properties with ultimate tensile strength (UTS) and yield strength (YS) of 346 MPa and 292 MPa, respectively, and an elongation of 26.7%, which can be attributed to the grain refining effect and precipitate strengthening. The UTS and elongation of Mg–2.3Zn–0.18Y–0.13Zr alloy changed slightly after aging treatment, but the YS increases remarkably, with the maximum increase of 30 MPa. The fracture surfaces of all alloys consist of many tearing ridges and dimples.

Evaluation of Emerging High Melting Point Lead-free Solder and Hybrid Sinter Paste as Attaching Material for Clip Bond Package

2020 ◽  
Vol 2020 (1) ◽  
pp. 000235-000241
Author(s):  
Fred Fuliang Le ◽  
Rinse van der Meulen ◽  
Yoon Kheong Leong ◽  
Manoj Balakrishnan ◽  
Zunyu Guan
Keyword(s):  
Melting Point ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reliability Testing ◽  
High Melting ◽  
High Melting Point ◽  
Basic Scheme ◽  
Free Solder ◽  
Lead Free Solders ◽  
High Lead

Abstract High melting point (HMP) lead-free solder, hybrid sinter and transient liquidus phase sinter (TLPS) are the emerging lead-free alternatives for the potential replacement of high-lead solder. Lead-free solder is perfectly compatible with existing high-lead soldering processes for clip bond packages. The benefit of hybrid sinter is that it has much higher thermal and electrical conductivity than lead-free or high-lead solder. In this study, ten materials (including lead-free solders, hybrid sinter paste and TLPS) were first evaluated via die shear test. With the initial material screening, two lead-free solders (solder 1 and 2), two hybrid Ag sinter pastes (sinter i and ii) and one TLPS proceeded to internal sample assembly. For the lead-free solders, a process optimization with the aid of vacuum reflow was made to reduce void rate. Due to the slow and unbalanced inter-diffusion of Ag-Cu sintering than Ag-Ag sintering, optimizations to enhance the hybrid Ag sintering include Ag finishing for the die metallization and Ag plating for the clip and bond area of the leadframe. In 0-hour package electrical test, solder 1 and sinter i passed and were sent for reliability testing while solder 2, sinter ii and TLPS failed due to intermetallic compound (IMC) cracking, material bleeding and die cracking, respectively. In the reliability testing, a basic scheme of thermal cycling (TC) 1000 cycles, intermittent operating life (IOL) 750 hrs and highly accelerated temperature and humidity stress test (HAST) 96 hrs was defined for the early feasibility study. 1 of 75 sinter i units failed by TC 1000 cycles due to separation between silver sinter structure and die bottom metallization. Solder 1 passed the basic scheme without defects, and next the material workability and clip bond strength need to be improved to the equivalent level of high-lead solders.

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