Ni元素对Sn-9Zn-3Bi无铅钎料显微组织和性能的影响

利用真空箱式电阻炉制备了Sn-9Zn-3Bi-xNi无铅钎料合金,并对其显微组织和主要性能(熔点、熔程、抗氧化性、润湿性、剪切强度)及钎焊接头断口形貌进行了分析。结果表明,少量Ni的加入可以细化Sn-9Zn-3Bi合金的显微组织,而对其熔点影响较小。当Ni添加量为0.1%和0.5%时,钎料的熔程变化不大,Ni添加量为1%时,钎料的熔程增大比较明显。随着Ni添加量增多,无铅钎料的抗氧化性能和润湿性能提高。Ni添加量在0.1%和0.5%时,钎焊接头的剪切强度变化不大,但韧性增加;Ni添加量在1%时,钎焊接头的剪切强度略有增大,但韧性降低。     

Mg对Sn-0.7Cu钎料组织及性能的影响

研究了Mg元素对Sn-0.7Cu共晶钎料微观组织、熔化特性、润湿性能及力学性能的影响,结果表明:Mg元素的适量添加能细化钎料的共晶组织,过量添加时共晶组织消失,同时使Cu6 Sn5颗粒由细小的颗粒状转变为短棒状.钎料的液相线温度随Mg含量的增加显著降低,当Mg含量为1.0％(质量分数)时,钎料的液相线温度降低到222.58℃,固液温度区间值不断增大,过冷度先增大后减小;钎料合金的润湿性随着Mg含量的增加呈先增大后减小的趋势,Mg含量为0.1％(质量分数)时,钎料合金的润湿性能最佳,铺展面积为85.74 mm2,相对于Sn-0.7Cu钎料提高了4.37％;Mg元素能够显著提高钎料的显微硬度,当Mg含量为1.0％(质量分数)时,钎料的显微硬度达到最大值,相对于Sn-0.7Cu提高了17.2％.     

添加Ag元素对铝软钎焊用Sn-1.5Zn系钎料性能的影响

研究了添加不同含量Ag元素对铝软钎焊用Sn-1.5Zn系钎料合金的熔化特性、显微组织、润湿性及钎焊接头抗腐蚀性能的影响。研究结果表明,Ag元素的添加缩短了Sn-1.5Zn钎料的熔程,细化了显微组织;采用润湿平衡法测量结果发现,添加Ag元素提高了钎料对铝基体的最大润湿力Fmax,但使润湿时间t0增加;采用3%(质量分数)浓度盐水溶液浸泡焊点实验结果表明,添加Ag元素提高了钎焊接头的抗腐蚀性。     

液态Sn-Ag-Cu钎料润湿性能的优化

采用钎料改性工艺制备了Sn-3.5Ag0.6Cu合金,用润湿平衡法测试了液态Sn-3.5Ag0.6Cu钎料在铜基体表面的润湿性,研究了钎料制备工艺、钎剂卤素含量、浸渍温度和时间等因素对润湿性能的影响.结果表明:采用改性工艺可增强钎料的润湿性能,当钎剂卤素含量为0.4wt%、在270℃下浸渍2～3s时,液态Sn-3.5Ag0.6Cu钎料对铜表面的润湿性可以达到最佳状态.指出降低钎料的熔点和液态表面张力是提高润湿性的关键.     

关于液态Sn—Ag—Cu钎料润湿性能的实验研究

采用钎料改性工艺制备了Sn-3．5Ag0．6Cu合金，用润湿平衡法测试了液态Sn-3．5Ag0．6Cu钎料在铜基体表面的润湿性，研究了钎料制备工艺、钎剂卤素含量、浸渍温度和时间等因素对润湿性能的影响。结果表明：采用改性工艺可增强钎料的润湿性能，当钎剂卤素含量为0．4％（质量分数）、在270℃下浸渍2～3s时，液态Sn-3．5Ag0．6Cu钎料对铜表面的润湿性可以达到最佳状态。指出降低钎料的熔点和液态表面张力是提高润湿性的关键。     

添加Bi和P对Sn-0.7Cu无铅钎料合金性能的影响

研究了添加Bi和P对Sn-0.7Cu无铅钎料合金熔点、显微组织、在Cu上的润湿性、导电率、硬度以及蠕变抗力等性能的影响。实验结果显示,随Bi含量增加,Sn-0.7Cu合金的熔点、导电率略有降低,润湿性、抗蠕变性能和维氏硬度均提高;此外,在添加Bi的基础上加P元素,能进一步降低Sn-0.7Cu-Bi合金的熔点,提高合金的导电率和润湿能力,但合金硬度略有下降;Sn-0.7Cu-1Bi-0.05P钎料合金的抗蠕变性优于Sn-0.7Cu-1Bi,Sn-0.7Cu-3Bi-0.05P钎料合金的抗蠕变性则劣于Sn-0.7Cu-3Bi。金相显微组织观察表明,单独加Bi能细化Sn-0.7Cu合金中的Cu6Sn5金属间化合物相;P的加入使Sn-0.7Cu-1Bi合金中的β-Sn枝晶尺寸变小,且Cu6Sn5相呈规则网络状分布于枝晶间隙;而在Sn-0.7Cu-3Bi合金中加P则粗化了Cu6Sn5相,并使IMC呈无规则分布。     

Sn-9Zn-xAg钎料在Cu基材上润湿性能及界面组织的研究

研究了添加合金元素Ag对Sn-9Zn无铅钎料显微组织、在铜基上的润湿性能及对钎料/铜界面组织的影响.研究结果表明:当Ag的含量(质量分数,下同)在0.1%～0.3%时,钎料中针状富Zn相逐渐减少,当Ag的含量在0.5%～1%时,钎料中出现Ag-Zn化合物相;当Ag的含量为0.3%时,钎料具有最好的润湿性能,当Ag的含量为0.5%～1%时,钎料的润湿性能下降;Sn-9Zn/Cu的界面处形成平坦的Cu5Zn8化合物层,当Ag含量为0.3%时,在Cu5Zn8化合物层上出现节结状的AgZn3化合物相,随着Ag含量的提高,这种节结状的AgZn3化合物相逐渐聚集长大成扇贝状的化合物层.     

合金元素对Sn-57Bi无铅钎料组织及韧性的影响

研究了添加不同含量的合金元素Ag,Ge,Cu,Sb,Zn,Ce,P,Ni对Sn-57Bi钎料的熔化温度、润湿性能、冲击韧性和显微组织的影响。研究结果表明,合金元素的添加对于钎料的熔化特性的影响不大,P,Ni的加入会导致出现硬脆的Bi,削弱了钎料的性能,Ag3Sn和富锌相则在形状合适时可以强化钎料的性能。单独加入合金元素Ag,Ge,Zn,Cu可以改善钎料的塑韧性,Ag,Ge还可以提高钎料的屈服强度和接头的剪切强度。合金元素Sb,Ce,P,Ni的加入会弱化钎料的塑韧性。而在同时添加多种合金元素的钎料合金中,43Sn-Bi-1Ge-1Ag的改善效果最好。     

纳米结构强化的新型Sn-Ag基无铅复合钎料

通过外加法向Sn-3.5Ag钎料中加入质量分数为1%,2%和3%的纳米级多面齐聚倍半硅氧烷(polyhedral oligomeric silsesquioxanes,POSS)颗粒制备无铅复合钎料.系统研究POSS颗粒的显微组织,钎料的熔化特性、润湿性能和力学性能.结果表明:POSS颗粒的加入并没有改变Sn-Ag基复合钎料熔化温度.复合钎料的铺展面积均有所增加,润湿角有所下降,表现了良好的润湿性.POSS颗粒的加入显著提高钎料钎焊接头的剪切强度.     

Sn-0.65CuX亚共晶改性钎料的液态性能

采用一种新的制造工艺,制备了Sn-0.65CuX(X为Ga、In、Bi、Ge、Sb、Ni、P、Re等掺杂元素)亚共晶改性钎料,研究了液态钎料在265℃温度下的抗氧化性、润湿性和漫流性.结果表明,原子掺杂与亚共晶的成分设计可以显著改善液态钎料的工艺性能,并延长钎料在使用条件下成分和性能的稳定性.在265℃大气气氛下,液态Sn-0.65CuX改性钎料表面氧化渣的生成速率仅为0.38mg/cm2·min;当采用RMA-flux钎剂时,在铜表面的润湿时间为0.88s,3s润湿力为0.79mN,扩展率为77.5%.     

Properties and microstructure of Sn-9Zn lead-free solder alloy bearing Pr

In the present work, effects of trace amount of Pr on the microstructure, wettability and mechanical properties of Sn-9Zn solder were studied. The range of Pr content in Sn-9Zn solder alloys varied from 0.01 to 0.25 wt%. Test results indicate that adding appropriate amount of Pr can evidently improve the wettability and mechanical properties of the Sn-9Zn solder alloy. The Sn-9Zn-0.08Pr solder shows the best comprehensive properties compared to other solders with different Pr content. At the same time, notable changes in microstructure were found compared with the Pr-free alloy. The needle-like Zn-rich phase in the Sn-9Zn solder was refined and became more uniform. Moreover, the thickness of the IMC layer at Sn-9Zn/Cu substrate was remarkably depressed with Pr addition.     

Effect of Ni Content on Mechanical Properties and Corrosion Behavior of Al/Sn－9Zn－xNi/Cu Joints

The effects of Ni content on the microstructure and the wetting behavior of Sn-9Zn-xNi solders on Al and Cu substrates, as well as the mechanical properties and electrochemical corrosion behavior of Al/Sn-9Zn-xNi/Cu solder joints, were investigated. The microstructure of Sn-9Zn-xNi revealed that tiny Zn and coarsened Ni 5 Zn 21 phases dispersed in the β-Sn matrix. The wettability of Sn-9Zn-xNi solders on Al substrate was much better than that on Cu substrate. With increasing Ni content, the wettability on Cu substrate was slightly improved but became worse on Al substrate. In the Al/Sn-9Zn-xNi/Cu joints, an Al4.2Cu3.2Zn0.7 intermetallic compound (IMC) layer formed at the Sn-9Zn-xNi/Cu interfaces, while an Al-Zn-Sn solid solution layer formed at the Sn-9Zn-xNi/Al interface. The mixed compounds of Ni3Sn4 and Al3Ni dispersed in the solder matrix and coarsened with increasing Ni content, thus leading to a reduction in shear strength of the Al/Sn-9Zn-xNi/Cu joints. Al particles were segregated at both interfaces in the solder joints. The corrosion potentials of Sn-9Zn-xNi solders continuously increased with increasing Ni content. The Al/Sn-9Zn-0.25Ni/Cu joint was found to have the best electrochemical corrosion resistance in 5% NaCl solution.     

The effect of 0.5 wt.% Ce additions on the electromigration of Sn9Zn BGA solder packages with Au/Ni(P)/Cu and Ag/Cu pads

It has previously been established that Sn-9Zn-0.5Ce alloy possesses mechanical properties superior to those of undoped Sn-9Zn alloy, and is free of the problem of rapid whisker growth. However, no detailed studies have been conducted on the electromigration behavior of Sn-9Zn-0.5Ce alloy. In this research, Sn-9Zn and Sn-9Zn-0.5Ce solder joints with Au/Ni(P)/Cu and Ag/Cu pads were stressed under a current density of 3.1 × 10⁴ A/cm² at room temperature for various periods of time. Due to finer grain sizes, the electromigration effects were more severe in Sn-9Zn-0.5Ce solder joints than in Sn-9Zn solder joints when joint temperature was around 80 °C. In addition, both solder joints (Sn-9Zn and Sn-9Zn-0.5Ce) with Au/Ni(P)/Cu pads possess longer current-stressing lifetimes than those with Ag/Cu pads because Ni is more resistant than Cu to migration driven by electron flow.     

无铅焊料的盐雾腐蚀性能研究

无铅焊料已经进入实用化研究阶段，Sn-3Ag-0．5Cu及sn-8Zn-3Bi等几种典型合金在-些电子产品中已经得到实际应用。然而对于上述无铅焊料的腐蚀性却报道较少。选取Sn-3Ag-0．5Cu、Sn-8Zn-3Bi及Sn-8Zn-3Bi—Nd合金进行盐雾腐蚀实验，对腐蚀表面进行宏观及微观分析，并与传统的sn—Pb焊料对比，考察焊料合金的耐腐蚀性能。结果表明：Sn-3Ag-0．5Cu具有比传统Sn—Pb焊料更优越的耐腐蚀性能；Sn-8Zn。3Bi合金由于组织中存在更为粗大的初生Zn相易于优先腐蚀而导致抗盐雾腐蚀性能不良，因此在腐蚀开始阶段腐蚀速率相对Sn-8Zn-3Bi—Nd合金更快，但后者初生相数量更多，因此在更长时间腐蚀后腐蚀量更大。     

Effects of 0.1 wt% Ni addition and rapid solidification process on Sn–9Zn solder

Effects of 0.1 wt% Ni addition and rapid solidification process on Sn–9Zn solder alloy were investigated. Characteristics of Sn–9Zn–0.1Ni alloy were analyzed compared with those of as-solidified Sn–9Zn alloy. Mechanical properties and interfacial microstructure of solder/Cu joints obtained using these solders were comparatively studied. By comparison with as-solidified Sn–9Zn alloy, the wettability of solder was obviously improved with 0.1 wt% Ni addition, and the melting behavior of the solder was promoted due to the rapid solidification process. The corrosion resistance of as-solidified and rapidly solidified Sn–9Zn–0.1Ni alloys was improved due to the formation of Ni–Zn intermetallic compound (IMC) and the refining of Zn-rich phases. Formation and growth of IMCs at the interface of Sn–9Zn–0.1Ni/Cu joints was significantly depressed. Rapid solidification process promoted the interfacial reaction during soldering and improved the bonding strength of joints.     

Sn-9Zn-xP无铅焊料合金性能研究

以Sn-9Zn合金为研究对象,考察了P的添加对其性能的影响,并对其机制作了初步探讨。通过二次离子质谱(SIMS)分析发现,P的添加显著降低Sn-9Zn合金中的含氧量,从而提高了合金在Cu上的润湿性。P的改善润湿性的效果不仅有利于其工艺性能,也提高了Sn-9Zn/Cu焊点界面的结合强度,只使其塑性略有下降。同时,微量P的添加不改变Sn-9Zn合金与Cu形成的焊点的界面结构。另外,蠕变强度测试结果表明,P的添加能显著提高合金的抗蠕变性能。     

Effect of addition of Al and Cu on the properties of Sn–20Bi solder alloy

This study investigates the effect of the composite addition of Al and Cu on the microstructure, physical properties, wettability, and corrosion properties of Sn–20Bi solder alloy. Scanning electron microscopy and X-ray diffraction were used to identify the microstructure morphology and composition. The spreading area and contact angle of the Sn–20Bi–x (x?=?0, 0.1 wt% Al, 0.5 wt% Cu, and 0.1 wt% Al–0.5 wt% Cu) alloys on Cu substrates were used to measure the wettability of solder alloys. The results indicate that the alloy with 0.1 wt% Al produces the largest dendrite and the composite addition of 0.1 wt% Al and 0.5 wt% Cu formed Cu₆Sn₅ and CuAl₂ intermetallic compounds in the alloy structure. And the electrical conductivity of Sn–20Bi–0.1Al is the best, which reaches 5.32 MS/m. The spread area of the solder alloy is reduced by the addition of 0.1 wt% Al and 0.5 wt% Cu, which is 80.7 mm². The corrosion products of Sn–20Bi–x solder alloys are mainly lamellar Sn₃O(OH)₂Cl₂ and the corrosion resistance of 0.1 wt% Al solder alloy alone is the best. The overall corrosion resistance of Sn–20Bi–0.1Al–0.5Cu is weakened and the corrosion of solder alloy is not uniform.

     

Optimization of N18 Zirconium Alloy for Fuel Cladding of Water Reactors

In order to optimize the microstructure and composition of N18 zirconium alloy(Zr-1Sn-0.35Nb-0.35Fe-0.1Cr,in mass fraction,%),which was developed in China in 1990s,the effect of microstructure and composition variation on the corrosion resistance of the N18 alloy has been investigated.The autoclave corrosion tests were carried out in super heated steam at 400 ℃/10.3 MPa,in deionized water or lithiated water with 0.01 mol/L LiOH at 360 ℃/18.6 MPa.The exposure time lasted for 300-550 days according to the test temperature.The results show that the microstructure with a fine and uniform distribution of second phase particles(SPPs),and the decrease of Sn content from 1%(in mass fraction,the same as follows) to 0.8% are of benefit to improving the corrosion resistance;It is detrimental to the corrosion resistance if no Cr addition.The addition of Nb content with upper limit(0.35%) is beneficial to improving the corrosion resistance.The addition of Cu less than 0.1% shows no remarkable influence upon the corrosion resistance for N18 alloy.Comparing the corrosion resistance of the optimized N18 with other commercial zirconium alloys,such as Zircaloy-4,ZIRLO,E635 and E110,the former shows superior corrosion resistance in all autoclave testing conditions mentioned above.Although the data of the corrosion resistance as fuel cladding for high burn-up has not been obtained yet,it is believed that the optimized N18 alloy is promising for the candidate of fuel cladding materials as high burn-up fuel assemblies.Based on the theory that the microstructural evolution of oxide layer during corrosion process will affect the corrosion resistance of zirconium alloys,the improvement of corrosion resistance of the N18 alloy by obtaining the microstructure with nano-size and uniform distribution of SPPs,and by decreasing the content of Sn and maintaining the content of Cr is discussed.     

Effect of a Trace of Bi and Ni on the Microstructure and Wetting Properties of Sn-Zn-Cu Lead-Free Solder

The microstructure and melting behavior of Sn-9Zn-2Cu （SZC） lead-free solder with 3 wt pct Bi and various amount of Ni additions were studied. The wetting properties and the interracial reaction of Sn-Zn-Cu with Cu substrate were also examined. The results indicated that the addition of 3 wt pct Bi could decrease the melting point of the solder and Ni would refine the microstructure and the rod-shape Cu5Zn8 phase changed into square-shape （Cu, Ni）5Zn8 phase. The addition of Bi, Ni greatly improved the wettability of SZC solder. In addition, the interracial phase of the solders/Cu joint was typical planar Cu5Zn8 in SZC-3Bi-INi alloy.