Ga2O3对Ag30CuZnSn药芯银钎料钎缝组织及钎焊接头性能的影响

向Ag30CuZnSn药芯银钎料药粉中添加Ga₂O₃,研究了Ga₂O₃对Ag30CuZnSn药芯银钎料钎缝组织的影响及钎焊接头性能的影响. 结果表明,微量Ga₂O₃可以显著提高Ag30CuZnSn药芯银钎料的润湿铺展性能且可以减少药芯中钎剂的添加量. Ga₂O₃添加量为0.4%（质量分数）时,钎料润湿铺展性能和钎焊接头抗剪切强度达到最佳值. 这是因为Ga₂O₃属于表面活性物质,可以显著降低熔融钎料和母材之间的界面张力,从而提高了钎剂粉末的去膜效果,进而提高银钎料的润湿铺展性能. 药芯银钎料基体及钎缝组织主要由以CuZn相为主的固溶体、银基固溶体和铜基固溶体构成. 火焰钎焊时,添加0.4%Ga₂O₃（质量分数）时作用效果最佳,钎缝组织的细化与钎着率的提高(钎着率提高至95%以上)使得钎焊接头抗剪强度提高了11%以上,钎焊接头断口组织的形貌证明了上述结果.     

Cu/Sn-58Bi-xEr_2O_3/Cu钎焊接头微观组织和力学性能的研究

研究了不同含量的纳米Er_2O_3颗粒对Sn-58Bi钎料的铺展性能、钎焊接头微观组织和力学性能的影响。结果表明,添加微量的纳米Er_2O_3颗粒细化了Sn-58Bi钎料的微观组织、改善了Sn-58Bi钎料的铺展性能和力学性能。当纳米Er_2O_3颗粒的添加量为0.075%(质量分数)时,Sn-58Bi复合钎料得到了最佳的铺展性能,比Sn-58Bi钎料的铺展系数增大了5.1%;当添加量为0.05%(质量分数)时,Sn-58Bi钎料的组织明显细化且到了最大的抗拉强度89 MPa,比Sn-58Bi共晶钎料的抗拉强度增大了11.5%。     

石墨烯纳米片对Sn-58Bi钎料显微组织和性能的影响

文中通过粉末冶金法在Sn-58Bi钎料中添加不同质量分数的石墨烯纳米片（GNSs）,以分析GNSs含量对Sn-58Bi钎料显微组织和性能的影响.结果表明,添加GNSs,对Sn-58Bi钎料熔点无明显影响;随着GNSs添加量提高,Sn-58Bi钎料的密度和显微维氏硬度先升高后降低;通过对比添加质量分数为0.05%的GNSs前后Sn-58Bi钎料/铜基板钎焊接头抗剪强度发现,添加GNSs后,由于能够起到细晶强化和弥散强化两方面作用,从而使钎焊接头抗剪切断裂能力提高.     

石墨烯纳米片增强的Sn-58Bi/Cu焊点可靠性

将不同含量（0%,0.025%,0.05%,0.075%,0.1%,0.2%,质量分数）的石墨烯纳米片（GNSs）添加到Sn-58Bi低温钎料中,研究了GNSs对钎料熔化温度、润湿性能、剪切强度、显微组织和界面反应的影响。结果表明：添加GNSs可以改善Sn-58Bi钎料焊点的润湿性能和抗剪切强度,但对其熔化温度的影响较小。随着GNSs的添加,钎料得到了相对细化的显微组织,界面金属间化合物（IMC）的厚度明显降低,并逐渐趋于平整。另外,随着GNSs的加入,Sn-58Bi钎料的剪切断裂模式从脆性断裂转变为脆性和韧性混合的断裂模式,这与其抗剪切强度的变化是一致的。因此,添加微量的GNSs是增强Sn-58Bi/Cu焊点可靠性的有效途径。     

镍包覆碳纳米管增强Sn-58Bi复合钎料焊点的组织和力学性能研究

研究了镍包覆碳纳米管(Ni-CNTs)对Sn-58Bi钎料焊点微观组织和可靠性的影响。结果表明:Ni-CNTs的添加提高了Sn-58Bi钎料润湿性能,复合钎料焊点界面IMC(intermetallic compound)呈现扇贝状,细化了Sn-58Bi钎料的微观组织,提高了复合钎料接头的拉伸和剪切性能。随着Ni-CNTs含量的增加,铺展面积呈现先上升后下降的趋势,IMC厚度呈现下降的趋势;复合钎料接头的抗拉强度和抗剪强度均呈现先上升后下降的趋势。当Ni-CNTs含量为0.03wt%时,复合钎料铺展面积最大,为58.3 mm2;复合钎料接头的抗拉强度和抗剪强度最大,分别为99.2、14.1 MPa。     

石墨烯纳米片增强的Sn-58Bi/Cu焊点可靠性（英文）

将不同含量(0%,0.025%,0.05%,0.075%,0.1%,0.2%,质量分数)的石墨烯纳米片(GNSs)添加到Sn-58Bi低温钎料中,研究了GNSs对钎料熔化温度、润湿性能、剪切强度、显微组织和界面反应的影响。结果表明:添加GNSs可以改善Sn-58Bi钎料焊点的润湿性能和抗剪切强度,但对其熔化温度的影响较小。随着GNSs的添加,钎料得到了相对细化的显微组织,界面金属间化合物(IMC)的厚度明显降低,并逐渐趋于平整。另外,随着GNSs的加入,Sn-58Bi钎料的剪切断裂模式从脆性断裂转变为脆性和韧性混合的断裂模式,这与其抗剪切强度的变化是一致的。因此,添加微量的GNSs是增强Sn-58Bi/Cu焊点可靠性的有效途径。     

硼酸铝晶须对Sn-58Bi/Cu界面金属间化合物 层演变及剪切行为的影响

研究了硼酸铝晶须对Sn-58Bi/Cu界面金属间化合物(IMC)层组织演变的影响.结合钎焊接头显微组织、剪切性能以及断口形貌,分析了Sn-58Bi-1.2%Al₁₈B₄O₃₃钎焊接头的断裂机理.结果表明,硼酸铝晶须的加入可以细化钎料组织,抑制大块富铋相的出现;钎料/基板界面IMC层厚度和晶粒粒径均随着重熔次数的增加而增大,但硼酸铝晶须的加入能够阻碍界面IMC层的增厚和晶粒粗化,提高钎焊接头的性能;不同重熔次数下Sn-58Bi-1.2% Al₁₈B₄O₃₃/Cu钎焊焊点比Sn-58Bi/Cu钎料焊点能承受更高的剪切载荷,且经过多次重熔后接头强度保持稳定.     

BaCe0.7Zr0.1Y0.1Yb0.1O3-δ质子导电陶瓷与不锈钢的空气反应钎焊分析

针对质子陶瓷燃料电池堆中BaCe_0.7Zr_0.1Y_0.1Yb_0.1O_3-δ (BCZYYb)质子导电陶瓷与Crofer22APU不锈钢的连接难题展开研究,探究了Ag-CuO钎料在BCZYYb陶瓷表面的润湿性能,分析了CuO与陶瓷反应对钎料润湿的驱动作用. 研究了Ag-CuO钎料的空气反应钎焊工艺,在1010 ℃/20 min工艺条件下实现了质子导电陶瓷与不锈钢的无缺陷连接,分析了接头两侧界面连接特性以及接头元素分布规律. 结果表明,CuO与陶瓷基体中BaO的反应促进了钎料润湿,钎料扩散进入陶瓷基体形成了较厚的渗透层,CuO与不锈钢保护层 (Mn, Co)₃O₄的反应促进了保护层致密化,保护层在连接过程对不锈钢基体起到了良好的保护作用. 系统分析了CuO含量对接头组织与性能的影响规律,采用Ag-CuO(2%,质量分数)钎料获得了最高接头剪切强度(21.6 MPa),综合评定了钎缝两侧界面反应对接头性能的影响.     

Er对Sn-58Bi钎料合金组织和性能的影响

采用真空熔炼方法制备了不同Er含量的Sn-58Bi钎料合金,研究不同Er添加量对Sn-58Bi钎料合金熔化特性、润湿性、拉伸性能和显微组织的影响。结果表明,Er元素的添加对Sn-58Bi钎料合金的熔点及熔程影响不大。当Er元素的添加量为0.05wt%～0.1wt%时,钎料合金的润湿性提高明显。Er元素添加量为0.1wt%～0.25wt%时,钎料合金的拉伸强度有所提高;钎料合金的伸长率提高明显,合金伸长率可由原15.34%(0wt%Er)提升至50.18%(0.1wt%Er)。添加稀土元素Er,能显著细化Sn-58Bi钎料合金的共晶组织。     

Ni含量对304/Sn-8Sb-4Cu-xNi/304钎焊接头组织与剪切性能的影响

研究了Ni含量对Sn-8Sb-4Cu-xNi(x=0, 0.5, 1和2,质量分数)钎料熔点和微观组织的影响,用Sn-8Sb-4CuxNi钎料对304不锈钢进行钎焊连接,分析了接头的界面组织与剪切性能.结果表明,添加不同含量的Ni后,Sn-8Sb-4Cu-xNi均为近共晶钎料,其熔点约为245℃;Sn-8Sb-4Cu钎料组织由α相基体、Sb₂Sn₃+Cu₆Sn₅+Sn复合相和Cu₆(Sn,Sb)₅相组成.添加Ni元素后,钎料中块状Cu₆(Sn,Sb)₅转变为细小、均匀分布的(Cu,Ni)₆(Sn,Sb)₅.当Ni含量小于1%时,随Ni含量的增加,钎料中的复合相和(Cu,Ni)₆(Sn,Sb)₅相均增加;当Ni含量为2%时,钎料中的复合相和(Cu,Ni)₆(Sn,Sb)₅相均减少,但(...     

热循环对Sn58Bi(纳米Ti)/Cu焊点界面与性能影响

为了改善Sn-58Bi低温钎料的性能,通过在Sn-58Bi低温钎料中添加质量分数为0.1%的纳米Ti颗粒制备了Sn-58Bi-0.1Ti纳米增强复合钎料。在本文中,研究了纳米Ti颗粒的添加对-55～125 _^oC热循环过程中Sn-58Bi/Cu焊点的界面金属间化合物(IMC)生长行为的影响。研究结果表明：回流焊后,在Sn-58Bi/Cu焊点和Sn-58Bi-0.1Ti/Cu焊点的界面处都形成一层扇贝状的Cu₆Sn₅ IMC层。在热循环300次后,在Cu₆Sn₅/Cu界面处形成了一层Cu₃Sn IMC。Sn-58Bi/Cu焊点和Sn-58Bi-0.1Ti/Cu焊点的IMC层厚度均和热循环时间的平方根呈线性关系。但是,Sn-58Bi-0.1Ti/Cu焊点的IMC层厚度明显低于Sn-58B/Cu焊点,这表明纳米Ti颗粒的添加能有效抑制热循环过程中界面IMC的过度生长。另外计算了这两种焊点的IMC层扩散系数,结果发现Sn-58Bi-0.1Ti/Cu焊点的IMC层扩散系数(整体IMC、Cu₆Sn₅和Cu₃Sn IMC)明显比Sn-58Bi/Cu焊点小,这在一定程度上解释了Ti纳米颗粒对界面IMC层的抑制作用。     

Improvement of mechanical properties of Sn-58Bi alloy with multi-walled carbon nanotubes

Carbon nanotubes (CNTs) reinforced Sn-58Bi composites were successfully fabricated through ball-milling method and low temperature melting process.The influence of multi-walled carbon nanotubes (MWCNTs) on the mechanical strength and ductility of Sn-58Bi lead-free alloy was studied.The mechanical test results show that the bending strength of Sn-58Bi-0.03CNTs (mass fraction,%) composite is increased by 10.5% than that of the Sn-58Bi alloy,which can be attributed to the reduction of Sn-rich segregation and the grain refinement.The toughness of Sn-58Bi-0.03CNTs composite is increased by 48.9% than that of the matrix materials.It is indicated that the influence of CNTs on the strength of Sn-58Bi-xCNTs composite is insignificant.In addition,the fracture mechanism of CNTs reinforced Sn Bi composite was analyzed.The corresponding fracture surface comparison between the Sn-58Bi-0.03CNTs composite and the monolithic Sn-58Bi alloy was made to identify the influence of CNTs on the fracture behavior and the reinforcing effect of CNTs.     

Understanding the Influence of Copper Nanoparticles on Thermal Characteristics and Microstructural Development of a Tin-Silver Solder

This paper presents and discusses issues relevant to solidification of a chosen lead-free solder, the eutectic Sn-3.5%Ag, and its composite counterparts. Direct temperature recordings for the no-clean solder paste during the simulated reflow process revealed a significant amount of undercooling to occur prior to the initiation of solidification of the eutectic Sn-3.5%Ag solder, which is 6.5 °C, and for the composite counterparts, it is dependent on the percentage of copper nanopowder. Temperature recordings revealed the same temperature level of 221 °C for both melting (from solid to liquid) and final solidification (after recalescence) of the Sn-3.5%Ag solder. Addition of copper nanoparticles was observed to have no appreciable influence on melting temperature of the composite solder. However, it does influence solidification of the composite solder. The addition of 0.5 wt.% copper nanoparticles lowered the solidification temperature to 219.5 °C, while addition of 1.0 wt.% copper nanoparticles lowered the solidification temperature to 217.5 °C, which is close to the melting point of the ternary eutectic Sn-Ag-Cu solder alloy, Sn-3.7Ag-0.9Cu. This indicates the copper nanoparticles are completely dissolved in the eutectic Sn-3.5%Ag solder and precipitate as the Cu₆Sn₅, which reinforces the eutectic solder. Optical microscopy observations revealed the addition of 1.0 wt.% of copper nanoparticles to the Sn-3.5%Ag solder results in the formation and presence of the intermetallic compound Cu₆Sn_5. These particles are polygonal in morphology and dispersed randomly through the solder matrix. Addition of microsized copper particles cannot completely dissolve in the eutectic solder and projects a sunflower morphology with the solid copper particle surrounded by the Cu₆Sn₅ intermetallic compound coupled with residual porosity present in the solder sample. Microhardness measurements revealed the addition of copper nanopowder to the eutectic Sn-3.5%Ag solder resulted in higher hardness.     

Bi对Sn-0.3Ag-0.7Cu无铅钎料熔点及润湿性能的影响

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。     

Combined effects of Bi and Sb elements on microstructure,thermal and mechanical properties of Sn-0.7Ag-0.5Cu solder alloys

This research investigated the combined effects of addition of Bi and Sb elements on the microstructure, thermal properties, ultimate tensile strength, ductility, and hardness of Sn-0.7Ag-0.5Cu (SAC0705) solder alloys. The results indicated that the addition of Bi and Sb significantly reduced the undercooling of solders, refined the β-Sn phase and extended the eutectic areas of the solders. Moreover, the formation of SbSn and Bi phases in the solder matrix affected the mechanical properties of the solder. With the addition of 3 wt.% Bi and 3 wt.% Sb, the ultimate tensile strength and hardness of the SAC0705 base alloy increased from 31.26 MPa and 15.07 HV to 63.15 MPa and 23.68 HV, respectively. Ductility decreased due to grain boundary strengthening, solid solution strengthening, and precipitation strengthening effects, and the change in the fracture mechanism of the solder alloys.     

凝固条件和应变速率对Sn-58Bi钎料拉伸性能和断裂行为的影响

研究了熔炼制备的Sn-58Bi无铅钎料于水冷、空冷、炉冷三种方式冷却后在应变速率0.001,0.002,0.004 s−1下的拉伸性能和断裂行为. 结果表明,水冷和空冷钎料共晶组织细小,尤其是空冷钎料共晶组织更为均匀,而炉冷钎料共晶组织粗大且偏析严重. 随着应变速率增大,三种钎料抗拉强度均提高而断后伸长率均变小. 炉冷钎料组织偏析导致硬脆富Bi相聚集,抗拉强度最大,但断后伸长率极低,为典型的脆性断裂;水冷和空冷钎料的均细共晶组织显著提高了钎料断后伸长率,具有更均匀共晶组织的空冷钎料断后伸长率最大,呈现韧性或韧脆性混合断裂.     

Solderability and intermetallic compounds formation of Sn-9Zn-xAg lead-free solders wetted on Cu substrate

The eutectic Sn-9Zn alloy was doped with Ag (0 wt.%-1 wt.%) to form Sn-9Zn-xAg lead-free solder alloys. The effect of the addition of Ag on the microstructure and solderability of this alloy was investigated and intermetallic compounds (IMCs) formed at the solder/Cu interface were also examined in this study. The results show that, due to the addition of Ag, the microstructure of the solder changes. When the quantity of Ag is lower than 0.3 wt.%, the needle-like Zn-rich phase decreases gradually. However, when the quantity of Ag is 0.5 wt.%-1 wt.%, Ag-Zn intermetallic compounds appear in the solder. In particular, adding 0.3 wt.% Ag improves the wetting behavior due to the better oxidation resistance of the Sn-9Zn solder. The addition of an excessive amount of Ag will deteriorate the wetting property because the glutinosity and fluidity of Sn-9Zn-(0.5, 1)Ag solder decrease. The results also indicate that the addition of Ag to the Sn-Zn solder leads to the precipitation of ε-AgZn₃ from the liquid solder on preformed interfacial intermetallics (Cu₅Zn₈). The peripheral AgZn₃, nodular on the Cu₅Zn₈ IMCs layer, is likely to be generated by a peritectic reaction L + γ-Ag₅Zn₈ → ɛ-AgZn₃ and the following crystallization of AgZn₃.