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Active soldering of 5A06 Al alloy was performed at 300℃ by using Sn-1Ti and Sn-1Ti-0.3Ga active solders, respectively. The effects of soldering time on the microstructure and mechanical properties of the joints were investigated. The results showed that the Sn-1Ti solder broke the oxide film on the surface of the Al substrate and induced intergranular diffusion in the Al substrate. When Ga was added to the solder, severe dissolution pits appeared in the Al substrate due to the action of Sn-1Ti-0...  相似文献   

3.
In this study, SEM, EDS, XRD and other test methods were used to study the effects of different Ga contents(0~2 wt.%) on microstructure, electrical conductivity, spreading area and mechanical properties of Sn-9 Zn-3 Bi solder. The results revealed that the microstructure of Sn-Zn-Bi-Ga solder alloy was mainly composed of β-Sn, Zn-rich, Bi-rich phase and Sn-Zn eutectic structure. The Ga can significantly improve the wettability of Sn-Zn-Bi on the pure copper, the maximum wetting area was 105.3 mm2. With the increase of the Ga content the melting point of the solders decreased from 195 ℃ to 177 ℃. In addition, the Ga element can increase the oxidation resistance of solder. Its conductivity showed a decreasing trend with the gradual increase of the Ga content. With the increased of the Ga content the IMC(Intermetallic Compound) of Sn-Zn-Bi-x Ga/Cu is only Cu5 Zn8 and its thickness decreased remarkably.  相似文献   

4.
Effects of Zn, Zn-Al and Zn-P additions on melting points, microstructures, tensile properties, and oxidation behaviors of Sn-40 Bi lead-free solder were investigated. The experimental results show that the addition of these three types of elements can refine the microstructures and improve the ultimate tensile strength(UTS) of solder alloys. The fractographic analysis illustrates that ductile fracture is the dominant failure mode in tensile tests of Sn-40Bi-2Zn(SBZ)and Sn-40Bi-2Zn-0.005Al(SBZA) specimens, while brittle fracture is the controlled manner in Sn-40Bi-2Zn-0.005P(SBZP) and Sn-58 Bi solders. XPS analysis indicates that trace amounts of both Al and P additives in solder can improve the antioxidant capacity, whereas only the additive of Al in solder can reduce the thickness of oxidation film.  相似文献   

5.
Trace amounts of La were utilized to improve the melting behaviors, microstructures, tensile properties and microhardness of Sn-3.0Ag-0.5Cu lead-free solder alloy. La has little effect on the melting behavior of Sn-3.0Ag-0.5Cu alloy according to the differential thermal analysis (DTA) tests. The X-ray diffraction (XRD) patterns show that β-Sn, Ag3Sn and Cu6Sn5 coexist in the as-cast solder alloys and LaSn3 phases emerge when adding 0.4% La. The microstructures modified by La are more uniform and much finer than that of baseline alloy, and the coarse LaSn3 particles with complex dendrites are observed by optical microscopy (OM) and scanning electron microscopy (SEM) when the addition of La is up to 0.4%. The composition of the LaSn3 phases is identified by energy-dispersive spectroscopy (EDS). There are considerable improvements in mechanical properties with 0.05% and 0.1% addition, but degenerations by adding 0.4%La. The Vickers microhardness of β-Sn and eutectic area are both enhanced with the addition of La and the microhardness of LaSn3 is much larger than those of β-Sn and eutectic area.  相似文献   

6.
The melting point, spreading property, mechanical properties and microstructures of Sn-3.0Ag-2.8Cu solder alloys added with micro-variable-Ce were studied by means of optical microscopy, scanning electron microscopy(SEM) and energy dispersive X-ray(EDX). The results indicate that the melting point of Sn-3.0Ag-2.8Cu solder is enhanced by Ce addition; a small amount of Ce will remarkably prolong the creep-rupture life of Sn-3.0Ag-2.8Cu solder joint at room temperature, especially when the content of Ce is 0.1%, the creep-rupture life will be 9 times or more than that of the solder joint without Ce addition; the elongation of Sn-3.0Ag-2.SCu solder is also obviously improved even up to 15.7%. In sum, the optimum content of Ce is within 0.05%-0.1%.  相似文献   

7.
To obtain novel intermediate temperature alloy solders with a melting temperature of 400-600°C,nominal(Ag-Cu28)-30Sn alloys without or with a trace addition(0.5 or 1.0 wt.%) of rare earth(RE) element La were prepared by mechanical alloying.The aim of this research is to investigate the effects of the addition of La on the microstructures,alloying process and melting properties of(Ag-Cu28)-30Sn alloys.The results show that the addition of La produces no new phase.A trace amount of La addition can effectively refine the grain size,but the excessive addition of 1.0 wt.% La inhibits the alloying process.The influence of La on the melting temperatures of solder alloys is negligible.However,the trace addition of 0.5 wt.% La can distinctly reduce the fusion zone and improve the melting property of(Ag-Cu28)-30Sn alloys.  相似文献   

8.
Several important properties of the micron-powdered Sn-Ag-Cu-Ce solder, including the spreadability, spreading ratio, wetting time, and melting point, were investigated for verifying the effects of rare earth element Ce on solderabilities of micron-powdered Sn-Ag-Cu solder. The solidus and the liquidus of the micron-powdered Sn-Ag-Cu-Ce solder are 193.6℃ and 218.4℃, respectively, about 28℃ and 3℃ lower than the melting point of the block Sn-Ag-Cu solder, which reminds the existence of the surface effect of the micron-powdered solder. By adding Ce into Sn-Ag-Cu alloy, its wetting time on pure copper can be obviously decreased. For the Sn-Ag-Cu-0.03?, the soldering temperature is 250℃, and the wetting time on pure copper is close to 1s, with the soldering temperature approaching to 260℃, the wetting time is dropped to 0.8s, which is close to the wetting time, 0.68s, of Sn-Pb solder at 235℃.  相似文献   

9.
The effects of Bi addition on the growth of intermetallic compound (IMC) formation in Sn-3.8Ag-0.7Cu solder joints were investigated. The test samples were prepared by conventional surface mounting technology. To investigate the element diffusion and the growth kinetics of intermetallics formation in solder joint, isothermal aging test was performed at temperatures of 100, 150, and 190 ℃, respectively. The optical microscope (OM) and scanning electron microscope (SEM) were used to observe microstructure evolution of solder joint and to estimate the thickness and the grain size of the intermetallic layers. The IMC phases were identified by energy dispersive X-ray (EDX) and X-ray diffractometer (XRD). The results clearly show that adding about 1.0% Bi in Sn-Ag-Cu solder alloy system can refine the grain size of the IMC and inhibit the excessive IMC growth in solder joints, and therefore improve the reliability of the Pb-free solder joints. Through observation of the microstructural evolution of the solder joints, the mechanism of inhibition of IMC growth due to Bi addition was proposed.  相似文献   

10.
The intrusion process of a C60 molecular ball into a sliding contact space with garaphene layered surfaces was simulated using the Molecular Dynamic approach.The contact space was made up by two silicon substrates with graphene layered on the surface of the upper substrate forming an included angle which was defined as initial entry angle changing from 20°to 90°.Then a linear velocity of 30/ps was applied to the lower substrate along horizontal direction.The simulation was carried out using Tesoff potential of C and Si atoms at room temperature 300K.The simulation results showed that when the intrusion angle exceeded a critical angle of 80°,the C60 ball could not intrude the contact space,and the number of the sticking atoms sharply increased.Also,the dependence of maximum pull-off force acting on the upper substrate on the initial entry angle during the C60 intrusion process was calculated in which the critical force for C60 intrusion is found.All the results showed that the upper silicon substrate was well protected by the mono graphene layer.  相似文献   

11.
In对Sn-8Zn-3Bi无铅钎料润湿性的影响   总被引:5,自引:1,他引:4  
首先采用铺展法测试了Sn-8Zn-3Bi-(0~5)In钎料合金的铺展性.结果表明,少量In的加入提高了钎料的润湿性.当In含量达到0.5%时(质量分数,下同),钎料在铜基底上的铺展面积最大.采用气泡最大压力法对Sn-8Zn-3Bi-(0~1.5)In钎料熔体进行了表面张力测试.加入0.5%的In大大降低了Sn-8Zn-3Bi钎料熔体的表面张力,但进一步增加In的含量导致熔体表面张力增大.最后采用润湿平衡法对上述钎料进行了润湿力测试.结果表明0.5%In的加入使合金的润湿力达到最大,其原因是钎料/铜界面的界面张力减小.  相似文献   

12.
Sn-Zn-Bi-(P,Nd)无铅钎料的微观组织及性能   总被引:1,自引:0,他引:1       下载免费PDF全文
研究了复合加入P,Nd元素的Sn-8Zn-3Bi钎料的微观组织、力学性能、抗氧化性及润湿性.结果表明,单独加入元素P会导致Sn-8Zn-3Bi钎料组织中出现初生Zn相,而同时加入元素P和Nd不仅能够抑制初生Zn相的形成,钎料组织也能够得到细化,因此钎料的塑性提高,断后伸长率达到48%.P,Nd元素的复合添加能够在钎料表面形成稳定的扩散阻挡层,抑制P元素在长时间加热条件下的烧损,进一步降低表面的氧化速度.由于钎料的抗氧化性提高,Sn-8Zn-3Bi-0.1P-0.05Nd钎料呈现出更好的润湿性.  相似文献   

13.
低熔点Sn-Zn-Bi无铅钎料的组织和性能   总被引:7,自引:0,他引:7  
周健  孙扬善  薛烽 《金属学报》2005,41(7):743-749
研究了Sn—Zn—Bi钎料的组织、相变及润湿性.在Sn-9Zn二元共晶的基础上加入质量分数为(2~10)%的Bi,合金结晶过程中形成富Zn的初生相.这导致合金的结晶温度降低,也标志着熔点的降低,但熔程扩大.在加Bi基础上,适当降低Zn的含量则可以缩小熔程,且熔点无明显变化.Bi的加入明显改善了Si—Zn系钎料的润湿性,提高了钎料在Cu基底上的铺展面积,缩短了润湿时间.钎料中Zn原子向Cu基底的扩散而形成扩散反应层,导致钎料熔体/Cu界面能的下降.因此,钎料中Zn含量提高,其在Gu基底上的铺展面积增大,润湿力提高.而由于扩散过程需要一定时间,导致润湿时间延长.因此,必须合理控制Zn的含量以获得铺展性与润湿时间的良好匹配.  相似文献   

14.
An orthogonal method was used to evaluate the effects of Ga, Al, Ag, and Ce multi-additions on the wetting characteristics of Sn-9Zn lead-free solders by wetting balance method. The results show that the optimal loading of Ga, Al, Ag, and Ce was 0.2 wt.%, 0.002 wt.%, 0.25 wt.%, and 0.15 wt.%, respectively. Intermetallic compounds (IMCs) formed at the interface between Sn-9Zn-0.2Ga-0.002Al-0.25Ag-0.15Ce solder and Cu substrate were investigated by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) analysis. The SEM images illustrate that the IMCs can be divided into two portions from the substrate side to the solder side: a planar Cu5Zn8 layer and an additional continuous scallop-like AgZn3 layer. The EDS analysis also shows that Ga segregates in the solder abutting upon the interface. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) of the surface components of Sn-9Zn-0.2Ga-0.002Al-0.25Ag-0.15Ce solder indicate that Al aggregates at the surface in the form of Al2O3 protective film, which prevents the further oxidation of the solder surface. On the other hand, Ce aggregates at the subsurface, which may reduce the surface tension of the solder and improve the wettability in consequence.  相似文献   

15.
Bi对Sn-0.3Ag-0.7Cu无铅钎料熔点及润湿性能的影响   总被引:5,自引:3,他引:2       下载免费PDF全文
研究了添加适量的Bi元素对低银型Sn-0.3Ag-0.7Cu无铅钎料合金性能的影响,应用差示扫描量热仪和SAT-5100型润湿平衡仪对Sn-0.3Ag-0.7Cu·xBi(x=0.1,3,4.5)钎料的熔点、润湿性能作了对比试验分析。结果表明,一定量Bi元素的加入可以降低Sn-0.3Ag-0.7Cu钎料合金的熔点,并改善其润湿性能。但过多的Bi元素会导致钎料的液固相线温度差增大,塑性下降,造成焊点剥离缺陷。综合考虑得到Sn-0.3Ag-0.7Cu-3.0Bi无铅钎料具有最佳的综合性能。  相似文献   

16.
稀土元素Nd对Sn-9Zn无铅钎料性能的影响   总被引:3,自引:2,他引:1  
研究了添加稀土元素Nd对Sn-9Zn无铅钎料的润湿性能、显微组织和焊点力学性能的影响.结果表明,Nd元素的加入改善了钎料的润湿性能,质量分数为0.06%时,钎料的润湿力最大,润湿时间最短,润湿性能达到最佳.随着Nd元素的加入,钎料的基体组织得到细化,富锌相逐渐减少,当元素Nd的添加量大于0.06%时,钎料的显微组织中出现小块状稀土元素Nd和Sn的金属间化合物.无铅钎料Sn-9Zn中稀土元素Nd的添加量为0.06%时,剪切力和拉伸力达到最大,分别提高了19.6%和26.6%,力学性能最佳.  相似文献   

17.
采用真空熔炼技术成功制备Sn-(8.98-x)Zn-0.02Al-xLa(x=0.02~0.12)焊料。采用XRD衍射、DTA、SEM等手段分析了焊料的熔点、显微结构及焊料对Cu基板的润湿性等性能。结果表明,添加适量的稀土元素La能较好地提高Sn-Zn-Al基焊料熔点,改善焊料的铺展能力和组织均匀性。在Sn-(8.98-x)Zn-0.02Al-xLa焊料中,稀土La的最佳添加量为0.04%。  相似文献   

18.
Maximum bubble pressure, dilatometric, and meniscographic methods were used in the investigations of the surface tension, density, wetting time, wetting force, contact angle, and interfacial tension of liquid alloys of Sn−Ag−Cu eutectic composition with various additions of Bi. Density and surface tension measurements were conducted in the temperature range 250–900 °C. Surface tensions at 250 °C measured under a protective atmosphere of Ar−H2 were combined with data from meniscographic studies done under air or with a protective flux. The meniscographic data with a nonwetted teflon substrate provided data on interfacial tension (solder-flux), surface tension in air, and meniscographic data with a Cu substrate allowed determinations of wetting time, wetting force, and calculation of contact angle. The calculated wetting angles from meniscographic studies for binary Sn−Ag eutectic and two ternary Sn−Ag−Cu alloys were verified by separate measurements by the sessile drop method under a protective atmosphere with a Cu substrate. Additions of Bi to both ternary alloys improve the wettability and move the parameters somewhat closer to those of traditional Sn−Pb solders.  相似文献   

19.
The ADAMIS database was used for calculation of the surface tension of the quaternary Sn−Ag−Cu−Bi liquid alloys by Butler's model. The resultant data were compared with those from the maximum bubble pressure measurements from Part I. The same thermodynamic database was next applied for the calculation of various phase equilibria. It was established that the Bi addition to the ternary Sn−Ag−Cu alloys (Sn-2.6Ag-0.46Cu and Sn-3.13Ag-0.74Cu in at.%; Sn-2.56Ag-0.26 Cu and Sn-2.86Ag-O.40Cu in mass%) causes lowering of the melting temperature and the surface tension to make the tested alloys closer to, traditional Sn−Pb solders. The simulation of the solidification by Scheil's model showed that the alloys with the higher Bi concentration are characterized by the lifting-off failure due to the segregation of Bi at the solder/substrate boundary. Thus, in modeling of new Pb-free solders, a compromise among various properties should be taken into consideration.  相似文献   

20.
通过改良静滴法研究Zn-xBi(x=0.5,1.0,1.5,2.0)合金熔体在450℃下与不同基板的润湿行为,对润湿反应之后的表面张力进行计算,并使用扫描电镜能谱仪(SEM-EDS)分析润湿试验后的试样表面及截面的微观形貌和组织结构。结果表明,在450℃下,Zn-Bi合金表面张力随Bi含量增加呈现先减小再增大的规律。Zn-1.0Bi合金熔体与X80钢的接触角最小,表明添加1.0%Bi(质量分数)后的锌液润湿性最好。Zn-Bi合金熔体中Bi的含量对界面反应强度和界面结构产生影响,进而减小表面张力和接触角。润湿初期Bi元素的快速吸附降低锌液表面张力,使接触角减小。中期由界面反应强度控制,此时形成前驱膜且其促进锌合金熔体在钢基板的流动,从而改善润湿性。  相似文献   

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