溶质元素(Ni,Sn)总量对Cu-Ni-Sn合金导电性能的影响

为提升Cu-Ni-Sn合金的导电率,系统研究了溶质元素(Ni,Sn)含量对导电Cu合金导电率和硬度的影响。通过对现有典型牌号Cu合金进行成分解析,发现在Ni、Sn原子比为3/1时合金具有高的导电率和强度,故本工作固定Ni、Sn原子比为3,改变Ni和Sn总量,设计了一系列三元成分合金;采用真空电弧熔炼工艺制备合金锭,随后进行1093K/1h固溶+65%~75%变形冷轧+673K/2h时效处理。实验结果表明,经过固溶+变形+时效处理后的Cu合金的导电率随溶质元素(Ni+Sn)含量增加而降低,而硬度变化则呈相反趋势;系列Cu合金的弹性模量随(Ni+Sn)含量基本保持不变。由此,为使Cu合金的导电率不低于15.0%IACS、且保持一定的强度,溶质元素(Ni+Sn)含量应为10.0%≤y(Ni+Sn)≤16.0%(质量百分比含量为12.0%≤w(Ni+Sn)≤18.0%)。     

Zn—4%Al合金超塑性变形性能及添加Cu、Mg的影响

本文研究了Zn—4％Al合金的超塑性拉伸性能,板材成型性以及合金元素Cu、Mg对上述性能的影响。结果表明:在350℃以下的温度区间和1.38 ×10~(-3)/s以上的应变速率区间内,该合金的延伸率随温度的升高和应变速率的降低而提高;合金元素Cu、Mg可同时提高该合金的超塑性变形性能和室温强度;经超塑性变形后合金的室温强度明显提高。     

AB2型LaMgNi3.7M0.3(M=Ni、Al、Mn、Co、Sn、Cu)贮氢合金的晶体结构及电极性能

系统研究了LaMgNi3.7M0.3（M=Ni、Al、Mn、Co、Sn、Cu）合金的组织结构和电化学性能。XRD和电子探针显微分析（EPMA）结果表明：该系列合金主相均为LaMgNi4相，其中含Mn、Cu和Co元素在LaMgNia合金相中有一定的固溶度，LaMgNi3.7Sn0.3合金中的Sn元素主要以LaNiSn相析出；XRD全谱拟合分析表明：LaMgNi3.7Al0.3中Al元素主要占据在LaNi5相的3g位置。合会化元素在LaMgNi4相中的固溶度从大到小的顺序是Mn〉Cu〉Co〉Al〉Sn。电化学实验表明，该系列合金经1～3次循环即可活化，最大放电容量由245．2mAh／g（M=Sn）变化至293．2mAh／g（M=Co），但合金电极的循环稳定性均较差。合金电极的高倍率放电性能（HRD900%）从大到小依次为Al〉Sn〉Cu〉Mn〉Ni〉Co，其中氢原子在合金中的扩散时合金电极的高倍率放电性能起主要作用。     

稀土系非化学计量比La(NiMMn)5.6合金的储氢性能

借助X-ray及吸放氢性能测试装置研究了不同处理条件及元素替代对非化学计量比La(NiMMn)5.6合金(M=Sn,Al,Cu)的结构、活化性能、吸氢容量和平台压力等性能的影响,测试了不同温度下合金的PCT曲线.结果表明,无论退火处理、快速凝固、以及Sn,Cu,Al元素取代,合金都出现点阵常数a缩短,c伸长,单胞体积增大.与常规熔铸相比,退火处理和快速凝固均提高了合金的活化性能,且都大大提高了合金的贮氢性能和降低平台压,但快速凝固吸氢量有所降低;快速凝固+低温退火合金的吸氢量最大.分别以Sn,Cu,Al取代Ni,元素替代的La(NiMMn)5.6合金都降低了合金的平台压,平台压降低的顺序按Sn＞Al＞Cu而减少,且都大大减小了滞后.     

射孔弹弹体Fe-Ni-Cu-C粉末材料组织及性能研究

为分析合金元素对Fe-Ni-Cu-C合金的强化机理,拓宽射孔弹弹体制造技术及材料应用范围,以Fe-Ni-Cu-C合金为对象,研究Cu、Ni、C等元素含量对油田射孔弹弹体用粉末冶金材料组织及性能的影响规律.结果表明:Cu会使基体孔隙率增加,进而降低延伸率;Ni含量的增加使合金中铁素体含量减少而珠光体含量明显增多,合金的抗拉强度和硬度呈增大趋势变化,延伸率在Ni质量分数为3%时达到极值后逐渐减小;在C含量不变的情况下合金延伸率随着Ni含量的增加,出现先增加后降低的趋势变化.     

高Nb-TiAl合金的凝固组织与力学性能研究

研究了Al含量变化对高Nb-TiAl合金的凝固组织与力学性能的影响.结果表明:随着Al含量的增加,TiAl合金晶粒尺寸呈增加趋势;当Al含量为45.7%时,凝固过程中局部区域发生包晶转变,使晶粒尺寸显著增大;室温及700℃高温拉伸强度随着Al含量的增加而呈增加的趋势,但发生包晶转变致使室温及700℃高温拉伸强度下降约200MPa;Al含量对延伸率不敏感,持久性能随Al含量的增加呈增加趋势.为控制铸锭凝固后的组织与力学性能,尽量避开包晶转变区,合金中Al含量应低于45.7%.     

Sn8Zn3Bi-xCu/Cu焊接接头界面反应及力学性能研究

以Sn8Zn3Bi为研究对象,采用微合金化方法研究了不同含量的Cu元素对其显微组织、钎料合金与Cu基板钎焊后的界面金属间化合物(IMC)层尺寸及焊接接头剪切强度的影响。结果表明,Sn8Zn3Bi-xCu/Cu(x=0.3,0.5,0.8,1.0,1.5)焊接界面IMC主要为层状Cu5Zn8相。随着Cu含量的增加,界面IMC层的厚度逐渐减小,接头的剪切强度逐渐提高,Sn8Zn3Bi-1.5Cu/Cu接头剪切强度较Sn8Zn3Bi/Cu显著提高。经120℃时效处理后,Sn8Zn3BixCu/Cu(x=0,0.3,0.5,0.8,1.0,1.5)焊接接头剪切强度都明显下降,接头断裂方式由韧性断裂转为局部脆性断裂,但添加了Cu元素的钎料界面IMC生长速度较Sn8Zn3Bi钎料慢,因此Cu元素的添加抑制了界面IMC层的生长。     

Ag合金化对热挤压前后耐热Al-Cu-Mg合金组织和性能的影响

采用拉伸力学性能测试和金相分析 ,研究了Ag合金化对热挤压前后耐热Al Cu Mg合金组织与性能的影响。结果表明 ,Ag的微合金化可以改善热挤压后Al Cu Mg合金的显微组织 ,明显提高合金的强度、延伸率及高温热稳定性。显微组织分析认为 ,这主要归功于合金化后析出的Ω相的沉淀硬化。     

Al_xCoCrFeNiCu_2高熵合金的组织结构及力学性能

采用真空电弧熔炼技术制备出不同Al含量的AlxCo Cr Fe Ni Cu2的高熵合金,研究Al含量对该高熵合金的微观组织及力学性能的影响。结果表明,该铸态高熵合金合金具有简单的bcc相固溶体结构及fcc相固溶体结构。AlxCo Cr Fe Ni Cu2(x=1,2和3)合金中fcc相固溶体的含量在增加;当x=4,5时,合金中bcc相固溶体的含量增加。合金的硬度随着Al元素的增加而提高。制备出的5种合金中Al4Co Cr Fe Ni Cu2硬度值最高。Al3Co Cr Fe Ni Cu2高熵合金具有较高的屈服强度和断裂强度。     

Cu和Sn对钎焊料4343Al合金组织性能的影响

通过添加0-1.0%(质量分数)的Cu或Sn来合金化4343合金,获得一种熔点更低、抗塌陷性能更优良的钎焊材料。熔点测试结果表明,随Cu或Sn含量的增加,合金的固相线温度和液相线温度逐渐降低,添加1.0%的Cu或Sn后合金固相线温度、液相线温度降低10-15℃。微观组织和挤压变形后力学性能研究结果表明,随Cu或Sn含量的增加,铸态合金中含Cu的第二相量或Sn颗粒逐渐增多;热挤压后含Cu第二相趋于溶解,而Sn促进含Si、Fe第二相溶解;合金室温抗拉强度逐渐升高,但延伸率略有降低。模拟钎焊实验结果表明,添加Cu或Sn可降低4343合金的可钎焊温度,添加1.0%的Cu或Sn可使钎焊温度降低15-20℃。     

The bulk alloy microstructure and mechanical properties of Sn–1Ag–0.5Cu–xAl solders (x?=?0, 0.1 and 0.2?wt.?%)

This work investigates the effects of 0.1 and 0.2?wt.?% Al additions on bulk alloy microstructure and tensile properties as well as on the thermal behavior of Sn–1Ag–0.5Cu (SAC105) lead-free solder alloy. The addition of Al reduces the amount of Ag₃Sn intermetallic compound (IMC) particles and leads to the formation of larger Al–Ag IMC particles. Moreover, the addition of Al suppresses the formation of Cu₆Sn₅ IMC particles and leads to the formation of larger Al–Cu IMC particles. The Al added solders show a microstructure with large primary β-Sn grains. The tensile tests show that the 0.1?wt.?% Al addition reduces the elastic modulus, yield strength and ultimate tensile strength (UTS). However, the 0.2?wt.?% Al addition brings the yield strength up to SAC105 level and the UTS up to level slightly higher than that of SAC105, while its effect on reducing the elastic modulus becomes less dependent compared with the 0.1?wt.?% Al addition. Moreover, both 0.1 and 0.2?wt.?% Al additions deteriorate the total elongation. The two additions of Al slightly increase the solidus and liquids temperatures, while slightly reduce the pasty range, hence allowing the use of the Al-containing Sn–1Ag–0.5Cu alloys, to be consistent with the conditions of usage for conventional Sn–Ag–Cu solder alloys.     

Effect of Al on the microstructure and properties of Sn–0.7Cu solder alloy

Effect of Al on the microstructure and mechanical properties were investigated. The results showed that Al could depress the formation of eutectic phase in Sn–Cu–Al solder alloy. The intermetallic compounds of Sn–0.7Cu–0.03Al were refined compared with that of Sn–0.7Cu–0.015Al. Segregated CuAl intermetallic compound was observed in Sn–0.7Cu–0.15Al and Sn–0.7Cu–0.5Al solder alloy. Sn-whisker was observed on the polished surface of Sn–0.7Cu–0.15Al and Sn–0.7Cu–0.5Al. The ultimate tensile strength of Sn–0.7Cu–0.03Al and Sn–0.7Cu–0.5Al was found to be higher than that of Sn–0.7Cu–xAl (x = 0, 0.015 and 0.15). The elongation of Sn–0.7Cu–0.015Al was the highest. The creep performance of Sn–0.7Cu–0.03Al and Sn–0.7Cu–0.5Al was similar and higher than that of Sn–0.7Cu and Sn–0.7Cu–0.15Al.     

SiC颗粒尺寸及含量对SiCp／2024Al复合材料性能的影响

本文对粉末冶金法制备的SiCp/2024Al复合材料的性能进行了研究。随SiC颗粒尺寸的增大,复合材料的强度降低,而塑性和磨损抗力则增加。SiC颗粒尺寸对复合材料的物理性能没有什么影响。增加SiC颗粒含量,复合材料的强度、模量均增大,磨损抗力亦明显增加,而塑性和热膨胀系数则降低。     

Microstructure and interfacial reaction of Sn–Zn–x(Al,Ag) near-eutectic solders on Al and Cu substrates

Sn–Zn–x(Al,Ag) near-eutectic solders, namely Sn–8.3Zn–0.73Ag, Sn–8.4Zn–0.44Al and Sn–7.4Zn–0.26Al–0.68Ag (in wt%) with melting points of 200.74, 198.00 and 197.32 °C, respectively, as well as the Sn–9Zn eutectic solder, were used to join Al and Cu substrates. The addition of Ag led to the formation of dendritic AgZn₃ phases, while the addition of Al obviously refined the microstructure of Sn–Zn eutectic, as well as the AgZn₃ phases. The Sn–Zn–Al solder possessed the best wettability on both Cu and Al substrates among the four solders. Al_4.2Cu_3.2Zn_0.7 intermetallic compound (IMC) layers formed at the Sn–Zn–x(Al,Ag)/Cu interfaces while Al-rich (Zn) solid solutions at the Sn–Zn–x(Al,Ag)/Al interfaces of all the as-soldered joints. The shear strength of the Al/Sn–Zn–Al/Cu solder joints was the highest among the four solder joints. The declining degree of the shear strength of the Sn–Zn–x(Al,Ag) solder joints in 3.5 % NaCl solution was in agreement with the corrosion-resistance order of the bulk solders. The Al/Sn–Zn–Ag/Cu joint thus owned the best corrosion resistance.     

Al含量对选区激光熔化Al_(x)CoCrFeNi(x=0.3,0.5,0.7,1.0)的显微组织及纳米压痕的影响EI北大核心CSCD

采用气雾化法制备预合金粉末,通过选区激光熔化(selective laser melting,SLM)制备Al_(x)CoCrFeNi(x=0.3,0.5,0.7,1.0)高熵合金。通过X射线衍射仪、扫描电镜以及纳米压痕实验,综合分析Al_(x)CoCrFeNi的物相、微观组织、硬度、杨氏模量及蠕变曲线,探讨Al含量对Al_(x)CoCrFeNi显微组织及纳米压痕的影响。结果表明:Al含量对物相组织有显著影响,其中Al_(0.3)CoCrFeNi与Al_(0.5)CoCrFeNi为FCC结构,Al_(0.7)CoCrFeNi和Al_(1.0)CoCrFeNi为BCC/B2结构。Al_(0.3)CoCrFeNi和Al_(0.5)CoCrFeNi主要由等轴晶组成,Al_(0.7)CoCrFeNi和Al_(1.0)CoCrFeNi主要由柱状晶组成。随Al含量增加,孔隙及裂纹等缺陷增加。在Al_(0.3)CoCrFeNi和Al_(0.5)CoCrFeNi中没有观察到明显的熔池形貌。随Al含量增加,样品残余应力增加。随Al含量增加,硬度增加,由Al_(0.3)CoCrFeNi的447HV增加至Al_(1.0)CoCrFeNi的567HV。Al_(0.3)CoCrFeNi杨氏模量约为273 GPa,Al_(0.5)CoCrFeNi约为233 GPa,Al_(0.7)CoCrFeNi和Al_(1.0)CoCrFeNi杨氏模量相近,分别为240 GPa和242 GPa,硬度与杨氏模量的变化主要与组织及物相有关。与传统蠕变曲线不同,Al_(x)CoCrFeNi的纳米压痕蠕变曲线只包括瞬时蠕变和稳态蠕变两个阶段,其蠕变机制主要为位错蠕变,其中Al_(0.7)CoCrFeNi具有最好的抗蠕变性能。Al_(0.3)CoCrFeNi具有最好的打印成形性,其屈服强度为702 MPa,伸长率为27.5%。     

Vetiver–polypropylene composites: Physical and mechanical properties

Injection molded vetiver–polypropylene (PP) composites at various ratios of vetiver content and vetiver length were prepared. When compared to PP, vetiver–PP composites exhibited higher tensile strength and Young’s modulus but lower elongation at break and impact strength. An increase in vetiver content led to an increase in viscosity, heat distortion temperature, crystallization temperature, and Young’s modulus of the composites. On the other hand, the decomposition temperature, tensile strength, elongation at break, and impact strength decreased with increasing vetiver content. The chemical treatment of the vetiver grass improved the mechanical properties of the composites.     

钢/铝添加粉末激光焊接头界面组织与性能

基于密度泛函理论的第一性原理,利用层技术构建钢/铝激光焊接的Fe/Al界面模型,研究金属原子X(X=Sn,Sr,Zr,Ce,La)置换Fe/Al界面模型中Fe(Al)原子的合金形成热及其体系电子结构。结果表明:Sn,Sr,Ce优先置换Fe/Al界面处的Al原子,而La,Zr优先置换Fe/Al界面处的Fe原子,合金化促进Fe/Al界面电子在不同轨道之间的转移,增强Fe-Al的离子键性能,提高Fe/Al界面结合能力,改善Fe/Al界面的脆性断裂,其中Sn的合金化效果最显著。在此基础上,进行1.4mm厚DC51D+ZF镀锌钢和1.2mm厚6016铝合金试件添加Sn,Zr粉的激光搭接焊实验,结果显示:添加粉末可促进焊接熔池的流动性,改变接头界面成分和显微组织,添加Sn粉激光焊钢/铝接头的抗拉强度327.41MPa,伸长率22.93%,较添加Zr粉和未添加粉末有了明显提高。     

The effect of saccharin addition on the mechanical properties and fracture behavior of electroless Ni–Cu–P deposit on Al

In a previous study, the effects of additive saccharin on internal stress, diffusion, and crystallization behaviors of electroless Ni–Cu–P deposits on Al were examined. In this study, tensile test results and microhardness measurements were used to investigate the effect of additive saccharin on the mechanical properties and fracture behavior of electroless Ni–Cu–P deposits on Al. An increase in the saccharin content of the plating solution from 0 to 12 g/L results in nodule growth and void elimination in the deposits. The denser nodules in the deposit also cause a decrease in the tensile stress and reveal the effect of ΔTCE on compressive stress generation. Consequently, the mechanical properties of Ni–Cu–P/Al deposits in terms of microhardness, yield strength, modulus of elasticity, and ultimate tensile strength were improved. The fracture behavior of the deposit changes from transnodular to internodular when the saccharin addition is above 4 g/L.     

Effect of Cu/Zn on microstructure and mechanical properties of extruded Mg–Sn alloys

In this paper, the effect of Cu and Zn addition on mechanical properties of indirectly extruded Mg–2Sn alloy was investigated. Mg–2Sn–0.5Cu alloy exhibits a moderate yield strength (YS) of 225?MPa and an ultimate strength of 260?MPa, which are much higher than those of the binary Mg–2Sn alloy, and the elongation (EL) evolves as ～15.5%. Mechanical properties of the Mg–2Sn–0.5Cu alloy are deteriorated with more 3 wt-% Zn addition, and YS and EL are reduced as 160?MPa and ～10%. The detailed mechanism is discussed according to the work-hardening rate and strengthening effect related to the grain sizes, second phases and macro-textures. Grain refinement and proper texture are believed to play a critical role in both strength and ductility optimisation.     

聚醚砜含量对纤维素/聚醚砜中空纤维血液透析膜结构和性能的影响

以离子液体氯代1-烯丙基-3-甲基咪唑([AMIM]Cl)为溶剂来纺制纤维素/聚醚砜共混中空纤维膜,考察了聚醚砜含量对中空纤维膜结构与性能的影响。采用扫描电子显微镜(SEM)对膜内、外表面形态结构进行了观察,测试了中空纤维膜的水通量、截留率等渗透性能,最大拉伸强度、断裂伸长率、杨氏模量等力学性能以及透析性能。结果表明:随着聚醚砜含量的增加,中空纤维膜外表面孔洞结构变大,内表面结构变得更加疏松,膜孔隙率与水通量升高,最大拉伸强度、断裂伸长率、杨氏模量等力学性能则逐渐下降;对尿素的清除效率逐渐提升;对溶菌酶和牛血清白蛋白的清除效率逐渐增大,在聚醚砜含量为13%时分别达到最大值24.05%和19.91%。