添加In对SAC305焊料显微组织和性能的影响（英文）

在Sn-3.0Ag-0.5Cu(SAC305)焊料中熔入0.5%～10%(质量分数)的In粉以改变钎料的显微组织，进而改善焊料的性能。实验结果表明：β-Sn(In)、Ag₃(Sn,In)和Cu₆(Sn,In)₅相存在于所有的含In钎料中，在SAC305-10In焊料中发现了InSn₄物相。随着In含量的增加，β-Sn晶粒形核点增加，其形核模型由{101}转变为{301}，从而细化β-Sn晶粒，使得β-Sn的形态由粗大晶粒转变为交错晶粒，最后转变为多晶粒。结果表明，这种β-Sn晶粒形态转变引起细晶强化与固溶强化的联合作用，使得SAC305-xIn焊料的显微硬度随着In添加量的增加而显著升高。     

Ag、Bi、In和Sb添加对Sn-0.6Cu-0.05Ni-Ge无铅焊料性能的改变（英文）

对用于替换Sn-Pb共晶焊料的Sn-Ag-Cu(SAC)焊料来说,Sn-Cu-Ni-Ge焊料是一个巨大的挑战。本文作者研究添加Ag、Bi、In和Sb对Sn-0.6Cu-0.05Ni-Ge(SCNG)无铅焊料物理性能的影响及与铜基体的界面反应。研究SCNG-x焊料的熔化行为、显微组织、抗拉强度和润湿性。结果表明,Ag、Bi、In和Sb的引入对焊料的固相温度、液相温度和抗拉强度有微小的影响。但是,合金元素的浓度会影响焊料的冷却性能和凝固组织。除锑以外的合金元素的添加,提高了SCNG焊料的润湿性。合金元素的加入增加了金属间化合物层的厚度,这与焊料的冷却行为有关。SCNG-x焊料与铜基体之间的金属间化合物层形貌与典型的SAC焊料不同。总之,用Ag、Bi、In或Sb对SCNG焊料进行合金化,可以改善焊料的特性。     

氮弧焊原位合成硬质颗粒对堆焊熔敷层的影响

向一种新型Fe-Cr-C系堆焊粉芯中分别添加不同含量硼、钒元素,并在氮气作为主要保护气的条件下在Q235基体上制备熔敷层。用金相显微镜对熔敷层组织进行了观察,测定熔敷后试样的显微硬度并进行了分析。结果表明,熔敷层中析出硬质氮化物,添加硼元素后析出一定量硬质相导致熔敷层硬度进一步增加,随着硼元素含量增加,硬质相数量增加并逐渐聚集;加入钒元素后,析出相更加细小且分布均匀,随着钒元素含量增加析出相数量变化不大,熔敷组织硬度提升不明显。     

B对Al_(0.5)CoCrCuFeNi高熵合金组织、相组成及耐磨性能的影响（英文）

研究了Al_(0.5)CoCrCuFeNiB_x(x=0~1)的组织、相组成、硬度及耐磨性能。并预测了Al_(0.5)CoCrCuFeNiB_x(x=0~1)中简单固溶体形成规律。未添加硼元素的合金具有简单fcc固溶体结构。添加硼元素后,合金由简单fcc固溶体及多元硼化物组成。硼以硼化物形式析出,没有固溶到fcc固溶体中,因而添加硼对fcc固溶体的晶格常数无影响。硼化物的析出使合金的硬度提高,并且硬度随着硼含量的增加而呈线性增加。当硼含量x≤0.4时,合金的磨耗阻抗变化不明显,但当硼含量x≥0.6时,合金的磨耗阻抗随着硼含量增加而呈线性增加。随着硼含量的增加,合金的磨损机制由粘着磨损转变为氧化磨损。合金硬度与耐磨性能的提高是高硬度的粗大硼化物与韧性的fcc固溶体基体共同作用的结果。     

Co含量对Sn-0.7Cu合金组织演化及力学性能的影响

采用真空感应熔炼工艺制备了Sn-0.7Cu-x Co(x=0.5,1.0,1.5,2.0wt%)合金,分析了Co含量对钎料合金微观组织和力学性能的影响。结果表明,Co的添加增加了Sn-0.7Cu的熔化温度,合金熔点随着Co含量的增加而增大;Co的添加使Sn-0.7Cu合金组织中出现了短棒状或块状的Co Sn2金属间化合物相,其体积分数随着Co含量的增加而增多。随着Co含量的增加,Sn-0.7Cu-x Co合金的显微硬度和抗拉强度增大,但合金的延展性逐渐降低。     

原位合成多元硼化物对Al0.5CoCrCuFeNiBx高熵合金硬度与耐磨性能的影响

本文研究了Al0.5CoCrCuFeNiBx (x=0-1)的组织、相组成、硬度及耐磨性能。并预测了Al0.5CoCrCuFeNiBx (x=0-1)中简单固溶体形成规律。未添加硼元素的合金具有简单FCC固溶体结构。添加硼元素后,合金由简单FCC固溶体及多元硼化物组成。硼以硼化物形式析出,没有固溶到FCC固溶体中,因而添加硼对FCC固溶体的晶格常数无影响。硼化物的析出使合金的硬度提高,并且硬度随着硼含量的增加而呈线性增加。当硼含量x?0.4时,合多的磨耗阻变化不明显,但当硼含量x?0.6时,合金的磨耗阻抗随着硼含量增加而呈线性增加。 随着硼含量的增加,合金的磨损机制由粘着磨损转变为氧化磨损。合金硬度与耐磨性能的提高是高硬度的粗大硼化物与韧性的FCC固溶体基体共同作用的结果。     

Nb含量对Fe_(0.5)MnNi_(1.5)CrNb_x高熵合金微观结构和力学性能的影响（英文）

采用真空感应熔炼法制备了Fe_(0.5)MnNi_(1.5)CrNb_x(x=0,0.05,0.1,摩尔比)高熵合金,并分析了不同Nb含量对其组织和力学性能的影响。结果表明,不含Nb元素的合金具有单相fcc结构,其抗拉强度和断裂延伸率(即延展性)分别为519 MPa和47%。添加少量的Nb(x=0.05)后出现(200)织构和少量Fe_2Nb Laves相,合金的延展性增加到55%,并且抗拉强度增加到570 MPa。当Nb含量增加到x=0.1时,织构减少,而Fe_2Nb Laves相增多,抗拉强度和延展性分别为650 MPa和45%。     

Cr元素含量对TC21钛合金表面激光熔覆Ni-Al涂层组织与性能的影响

目的研究Cr元素含量对TC21钛合金表面激光熔覆Ni-Al涂层组织与性能的影响,改善其表面性能。方法利用激光熔覆技术在TC21钛合金表面制备不同Cr含量的Ni-Al涂层,采用带有能谱仪(EDS)的扫描电子显微镜(SEM)、X射线衍射仪(XRD)对熔覆层的显微组织、物相组成进行分析,采用显微硬度计和材料表面性能综合测试仪测试熔覆层的硬度分布和耐磨性能。结果熔覆层表面质量良好,未添加Cr元素时,熔覆层主要由Ni(Al,Ti)、Ni_2AlTi、Ti Ni等物相组成;添加Cr元素后,熔覆层中有α-Cr沉淀相析出,并且随着Cr元素含量的逐渐提高,Ti Ni、Ni_2AlTi、α-Cr等物相的相对含量逐渐增加。熔覆层主要由Ni(Al,Ti)枝晶组织与其周围呈网状分布的Ti Ni、Ni_2AlTi、α-Cr晶间组织构成。熔覆层的显微硬度均提高到基体的2倍左右,Cr元素对提高Ni-Al涂层显微硬度的影响不大,但能使其显微硬度波动减小,趋于平稳,熔覆层的韧性随着Cr元素含量的增加而不断提高。当Cr元素添加量为20%(原子数分数)时,耐磨性最好,约为基体的2.948倍。结论 Cr元素的添加,有利于熔覆层中α-Cr相的析出和Ti Ni/Ni_2AlTi共晶组织的生成,能有效降低熔覆层的室温脆性,提高塑韧性及耐磨性能。     

激光熔覆CoCrFeNiSix高熵合金涂层的组织与性能

为了探究Si元素含量对CoCrFeNiSi_x(x=0.5,1.0,1.5)高熵合金涂层的组织与性能的影响,采用激光熔覆技术制备高熵合金涂层,通过X射线衍射仪、扫描电子显微镜、能谱仪、显微硬度仪、摩擦磨损试验机、电化学工作站等表征了涂层的物相组成、微观组织以及元素分布、硬度值、耐磨性能和耐腐蚀性能. 研究表明,随着Si元素的含量增加,合金物相由单相面心立方结构转变为面心立方结构、Si元素化合物(σ)相结构,最后形成面心立方结构、体心立方结构和σ相混合结构.涂层的组织主要由柱状晶转变成树枝晶,最后形成胞状晶;同时,涂层的硬度不断提高,当Si含量为1.5时,涂层的平均硬度值达到最高,为619.04 HV0.2,约为基体的2.67倍.涂层的磨损量、摩擦系数随着Si含量的增加而减少,耐磨性能显著提高.涂层在3.5%NaCl溶液中腐蚀性能随着Si含量的增加先增加后降低,当Si含量为1.0时,涂层的耐腐蚀性能最优.     

Mo元素对激光熔覆AlCoCrFeNiMox高熵合金涂层组织性能的影响(英文)

采用激光熔覆的方法制备AlCoCrFeNiMox高熵合金涂层。研究Mo元素含量对涂层微观结构、硬度及耐腐蚀性的影响。结果表明,随着Mo含量的增加,微观组织从富(Al, Ni)的体心立方（bcc）相和富(Mo-Cr-Fe)的σ相,转变为富(Fe, Ni)的bcc相、富(Mo-Cr-Fe)的σ相、富(Al-Fe-Mo)的σ相与少量AlN相。此外,涂层的显微硬度（HV1）从6154.4 MPa增加到10652.6 MPa。随着Mo含量的添加,涂层在3.5%（质量分数）氯化钠溶液中的自腐蚀电位升高,当Mo含量为x=1.0时,涂层的耐腐蚀性能最好。     

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.     

铋和磷元素对Sn-Zn-RE电子微连接钎料组织与性能的影响

制备了含不同Bi,P元素的（Sn-9Zn0.05Ce）xBi和（Sn-9Zn0.05Ce）xP钎料合金,观察并分析了钎料的显微组织形貌,测试了钎料的抗拉强度、断后伸长率以及维氏硬度.结果表明,添加Bi元素能显著提高Sn-9Zn0.05Ce钎料合金的抗拉强度和硬度,但同时会明显降低其断后伸长率,而添加微量P元素对钎料的抗...     

Development of high strength Sn-0.7Cu solders with the addition of small amount of Ag and In

Nowadays, a major concern of Sn-Cu based solder alloys is focused on continuously improving the comprehensive properties of solder joints formed between the solders and substrates. In this study, the influence of Ag and/or In doping on the microstructures and tensile properties of eutectic Sn-0.7Cu lead free solder alloy have been investigated. Also, the effects of temperature and strain rate on the mechanical performance of Sn-0.7Cu, Sn-0.7Cu-2Ag, Sn-0.7Cu-2In and Sn-0.7Cu-2Ag-2In solders were investigated. The tensile tests showed that while the ultimate tensile strength (UTS) and yield stress (YS) increased with increasing strain rate, they decreased with increasing temperature, showing strong strain rate and temperature dependence. The results also revealed that with the addition of Ag and In into Sn-0.7Cu, significant improvement in YS (∼255%) and UTS (∼215%) is realized when compared with the other commercially available Sn-0.7 wt. % Cu solder alloys. Furthermore, the Sn-0.7Cu-2Ag-2In solder material developed here also exhibits higher ductility and well-behaved mechanical performance than that of eutectic Sn-0.7Cu commercial solder. Microstructural analysis revealed that the origin of change in mechanical properties is attributed to smaller β-Sn dendrite grain dimensions and formation of new inter-metallic compounds (IMCs) in the ternary and quaternary alloys.     

Sn-Cu-Ni焊点纳米压痕试验分析

为研究金属间化合物与无铅焊点力学性能之间的关系,采用纳米压痕法测定了Sn-Cu-Ni焊点中金属间化合物及钎料基体的弹性模量和压痕硬度等力学性能参量．结果表明,Sn-Cu-Ni焊点中（Cu,Ni）6Sn5金属间化合物的弹性模量为113．2GPa±4．8GPa,压痕硬度为5．59GPa±0．32GPa,均与钎料基体有较大差...     

稀土La对45Cr2NiMoVSi热作模具钢力学性能的影响

研究了稀土La对45Cr2NiMoVSi钢的强度、硬度、塑性和冲击韧度的影响。在相同的热处理工艺条件下,分别加入3种不同含量的稀土La,与不添加稀土La的45Cr2NiMoVSi钢的力学性能进行对比。结果表明：稀土La加入量在适当的范围内可显著提高45Cr2NiMoVSi的力学性能,稀土La加入量为0.20%（质量分数）时,45Cr2NiMoVSi钢可获得最好的综合力学性能。     

BGA单板结构与板级结构焊点剪切力学行为分析

采用试验方法研究BGA封装结构中焊点的剪切力学行为. 分析并比较了Sn-3Ag-0.5Cu,Sn-0.3Ag-0.7Cu,Sn-0.3Ag-0.7Cu-0.07La和Sn-0.3Ag-0.7Cu-0.07La-0.05Ce四种钎料焊点在单板结构与板级结构中的力学性能. 结果表明, 单板结构中焊点的抗剪强度高于板级结构中焊点的抗剪强度. 在单板结构中,高银焊点的抗剪强度最大,加入稀土元素的低银焊点只是得到了一定程度上的改善,然而对于板级结构,加入稀土元素的低银焊点剪切力学性能基本与高银焊点相当. 在同等拘束条件下,低银焊点的延展性优于高银焊点. 此外,对于同一种钎料而言,单板结构中的焊点断裂在体钎料上,而板级结构则断裂在IMC/体钎料界面处.     

NiAl力学性质合金化效应的第一原理计算

采用第一原理赝势平面波方法,计算几种合金化元素X(X=Cr、Mn、Fe、Co和Cu)与不同Fe含量(0,3.125%,4.167%,6.25%,摩尔分数)(NiFe)Al超胞的几何与电子结构,并采用如下几个力学参数:弹性常数C44、Cauchy压力参数(C12-C44)、弹性模量E和剪切模量G及比值G/B0等,表征和评判了合金化元素X与不同Fe含量对NiAl金属间化合物延性与硬度的影响。结果表明:高浓度(6.25%)合金化虽可提高NiAl晶体的硬度,但却导致NiAl延展性降低,合金化后NiAl硬度增加的次序为:(Ni7Mn)Al8>(Ni7Co)Al8>(Ni7Fe)Al8>(Ni7Cr)Al8>(Ni7Cu)Al8>NiAl,其延性降低次序则与硬度增加次序相反;随着Fe含量的升高,NiAl晶体的硬度增加,但其使硬度增加的上限约为4%,而随着Fe含量的降低,NiAl晶体的延性逐步增大,当Fe含量低到一定程度时,可改善NiAl晶体的本征脆性。     

Effect of Iron Impurity and a Cd Trace Addition on the Delayed Ageing of Al-7Si-0.3 Mg Casting Alloy

Abstract

Iron in aluminium alloys is considered to be an impurity. It forms intermetallic compounds with Al and elements Si and Mg; these coarse intermetallic compounds impair the mechanical properties. An increase in hardness and decrease in UTS, YS, and ductility was observed with an increase in Fe content in the range 0.2 to 0.8% in an Al-7Si-0.3Mg Alloy. Further analysis showed higher hardening rate of the alloy at 0.8% Fe compared to 0.2% Fe with the tensile flow curves. Studies were carried out on the effect of chemical composition (Mg, Fe), solidification rate, heat treatment (delayed ageing with Cd trace addition) on microstructure and mechanical properties of the alloy. Chill castings were found to possess higher mechanical properties than sand castings.     

Microstructural,mechanical and shape memory characterizations of Ti–Mo–Sn alloys

As a β stabilizing element in Ti-based alloys, the effect of Mo on phase constitution, microstructure, mechanical and shape memory properties was investigated. Different compositions of Ti–xMo–3Sn alloys (where x=2, 4, 6, at.%) were prepared by arc melting. A binary composition of Ti–6Mo alloy was also prepared for comparison. Ti–xMo–3Sn alloys show low hardness and high ductility with 90% reduction in thickness while Ti–6Mo alloy shows high hardness, brittle behavior, and poor ductility. Field emission scanning electron microscopy (FESEM) reveals round morphology of athermal ω (ω_ath) precipitates. The presence of ω_ath phase is also confirmed by X-ray diffraction (XRD) in both as-cast and solution-treated and quenched conditions. The optical microscopy (OM) and FESEM show that the amount of martensite forming during quenching decreases with an increase in Mo content, which is also due to β→ω transformation. The hardness trends reinforce the presence of ω_ath too. The shape memory effect (SME) of 9% is the highest for Ti–6Mo–3Sn alloy. The SME is trivial due to ω_ath phase formation; however, the increase in SME is observed with an increase in Mo content, which is due to the reverse transformation from ω_ath and the stress-induced martensitic transformation. In addition, a new and very simple method was designed and used for shape memory effect measurement.     

热处理对轧制AM50+xCa组织及力学性能的影响

研究了固溶、时效对轧制AM50＋xCa（x=0.1％,2％,质量分数）镁合金组织和力学性能的影响。结果表明：合金轧制后,随着固溶时间的增加,Mg17Al12相通过原子扩散弥散嘲溶到镁基体中;而Al2Ca相比较稳定,部分变细,逐渐断开并出现球化现象。随着时效时间的增加,Mg17Al12相以细粒状从过饱和的镁基体中析出;而Al2Ca相比较稳定,其数量和形状变化极小。固溶处理后,合金硬度和拉伸强度有所下降;时效处理后,合金硬度增加到峰值后下降,拉伸强度略有升高。固溶、时效处理肟轧制AM50和AM50＋1Ca镁合金的颦性有所增加;而轧制AMSO＋2Ca镁合金固溶后塑性有所增加,时效后塑性有所下降。