基于试验和数值模拟的TC1/1060/6061爆炸焊接复合板界面分析

将薄层钛合金板与铝合金板结合可以得到具有优异性能的钛/铝复合板,具有广阔的应用前景.采用爆炸焊接技术成功制备了TC1/1060/6061复合板,对2个界面的界面形貌和元素进行测试,分析夹层存在的优势;同时建立与试验条件一致的有限元模型,对界面状态和焊接过程进行分析,最后对复合板进行拉伸试验和剪切试验,验证界面结合质量.结果表明,TC1/1060界面为直线型形貌,1060/6061界面为波状形貌,且每个波形都伴随着涡流区,TC1/1060界面处的元素扩散范围为4.38μm,且没有检测到钛/铝金属间化合物的产生.数值模拟再现爆炸焊接过程中射流的形成,界面温度沿着界面形貌分布,界面压力在碰撞点处达到最大,且呈现出椭圆形分布,复合板具有较高的抗拉强度和剪切强度,满足结构使用需求.     

钛/铝/镁爆炸焊复合板波形界面及力学性能

文中提出以薄的铝合金板作为过渡层,采用爆炸焊接技术成功制备钛/铝/镁层状复合材料. 对钛/铝接合界面、铝/镁接合界面及钛/铝/镁爆炸复合板的整体力学性能进行了分析研究. OM和SEM试验结果表明,钛/铝接合界面和铝/镁接合界面均为波状接合界面,在铝/镁界面出现了局部熔化区;钛/铝接合界面为小尺寸波(λ=160 μm,h=26 μm),铝/镁接合界面为大尺寸波(λ=1 740 μm,h=406 μm);拉-剪试验表明,复合板沿着铝/镁接合界面断裂;弯曲性能测试表明,钛板一侧受拉时复合板弯曲强度和塑性均优于镁合金板一侧受拉,断裂始于铝/镁接合界面,最终从镁合金板一侧剪切断裂失效.     

钛/铝/钛三层板的一次爆炸复合制备及界面结合性能评价

为评价一次爆炸复合工艺制备的钛/铝/钛三层复合板的界面结合性能,利用SEM、EDS对钛/铝/钛复合板的双层界面组织形貌以及界面元素分布进行了表征;对钛/铝/钛三层复合板进行了拉伸实验和弯曲变形实验。研究结果表明：复合板界面主要由波状界面和平直状界面构成;铝元素与钛元素在界面上发生了互扩散;拉伸和弯曲变形结果表明,一次爆炸复合工艺制备的钛/铝/钛三层复合板具有较大的抗拉强度和优良的界面结合性能,可以承受后续较大的二次塑性变形。     

大规格高强度钛/纯钛/不锈钢爆炸焊接复合板性能研究

通过爆炸焊接工艺制备出大规格(大面积、大厚度)的化工用高强度钛/纯钛/不锈钢(Gr12/Gr1/316L)爆炸焊接复合管板,并对其结合质量、力学性能、结合界面形态进行研究。结果表明,复合板的结合质量良好,钛/不锈钢界面的剪切强度达到290 MPa以上,其力学性能也达到ASTM B898-2011(2016)标准要求和客户的验收指标;结合界面形态分析表明,钛/钛(Gr12/Gr1)界面呈现近似于直线状结合,钛/钢(Gr1/316L)界面呈现波纹状结合。     

钛/铝复合板爆炸焊接技术研究进展

通过爆炸焊接技术制备的钛/铝复合板可兼具钛合金耐腐蚀性和铝合金低成本的优点。对钛/铝复合板爆炸焊接技术的研究进展进行介绍,论述了炸药种类、质量比R、基覆板间距及爆炸焊接窗口等主要工艺参数对钛/铝复合板组织和性能的影响;分析了影响钛/铝复合板结合界面的主要因素——金属间化合物种类、扩散层和界面波形;对钛/铝复合板硬度、抗剪切强度、抗拉强度及拉伸断口的研究进行了汇总分析。最后,指出了钛/铝复合板爆炸焊接工艺研究的重点发展方向。     

钛/钢爆炸复合板界面波幅比与剪切强度关系研究

针对在不同爆炸复合工艺条件下生产的钛/钢复合板,通过在显微镜下观察其结合界面形态,测量其结合界面的波幅和波长,进行了波幅比的计算;同时,将界面波幅比与剪切强度进行分析对比,从而找出特定规格的钛/钢复合板界面波幅比与界面剪切强度的对应关系,为生产中钛/钢复合工艺优化提供参考依据.     

衬板轧制铝/镁/铝复合板的波纹界面结构及形成机理（英文）

提出一种采用衬板轧制进行AA1060铝/AZ31B镁/AA1060铝复合板的制备方法。结果表明：传统轧制铝/镁/铝复合板截面轮廓较为平直，而衬板轧制由于衬板可将剪切力部分转化为压应力，从而改变复合板板受力状态，在铝/镁界面连接处形成差速流动，故而界面轮廓呈现波浪状特征，层间实现互锁连接。界面连接强度为64 MPa，是传统轧制复合板的4倍。力学性能测试表明：衬板轧制复合板的抗拉强度可达210 MPa，比传统轧制法提高12.3%。综上可知，衬板轧制法为高性能铝/镁/铝异质复合板成形制造提供一种新思路。     

冷轧制备AlSn20Cu/钢多层板的微观组织和力学性能（英文）

通过室温冷轧制备出了1060Al/AlSn20Cu/1060Al/钢多层复合板材,并探索了轧制压下量对复合板微观组织和力学性能的影响。利用扫描电子显微镜和电子背散射衍射（EBSD）对复合板微观组织进行表征,通过拉伸试验测量了复合板力学性能。复合板的初始轧制压下量为17%,最小稳定压下量为40%。结果表明,随着轧制压下量的增加,铝合金层中锡相和钢中组织沿轧制方向被拉长,但是纯铝层呈现出等轴晶。随着轧制压下量的增大,复合板抗拉伸强度和界面结合强度增加,而延伸率下降。AlSn20Cu合金层的断裂主要跟其中的锡相有关。     

正火处理对Cu/Al爆炸焊接板显微结构及力学性能的影响

采用爆炸焊接技术制备出以T2紫铜为覆板、1060工业纯铝为基板的T2/1060层状复合板.300℃正火处理12,24,36,48 h后,对复合板结合界面的微观结构及各项力学性能进行了测试与分析.结果表明,T2/1060爆炸焊接板焊接质量良好,结合界面出现规则的、幅值/宽度分别约为35 μm/200 μm的波形结合.正火处理48 h后,两种元素在结合界面附近互相扩散明显,其扩散层的厚度、均匀程度有明显的提高;力学性能方面,试样的显微硬度、抗拉强度明显下降（分别从215 HV,255.7 MPa降为170 HV,228.8 MPa）,而延展性有明显提升（屈服应变由3.64%变为22.4%）.     

钛/铝/钛三层板的一次爆炸复合

为评价一次爆炸复合工艺制备的钛/铝/钛三层复合板的界面结合性能,利用SEM、EDS对钛/铝/钛复合板的双层界面组织形貌以及界面元素分布进行了表征;对钛/铝/钛三层复合板进行了拉伸试验和弯曲变形试验。结果表明:复合板界面主要由波状界面和平直状界面构成;铝元素与钛元素在界面上发生了互扩散;拉伸和弯曲变形结果表明,一次爆炸复合工艺制备的钛/铝/钛三层复合板具有较大的抗拉强度和优良的界面结合性能,可以承受后续较大的二次塑性变形。     

Structural, mechanical and corrosion properties of TiOxNy/ZrOxNy multilayer coatings

Results on the deposition and characterization of TiO_xN_y/ZrO_xN_y multilayers, with bilayer periods of 20 and 400 nm, are presented. The coatings were deposited on TiNiNb alloy substrates by the pulsed magnetron sputtering method. The elemental composition, hardness, adhesion and corrosion resistance of the coatings were analyzed.As resulted from the XPS analysis, the individual layers consisted of a mixture of titanium or zirconium oxynitrides and corresponding oxides. X-ray analysis revealed that the coatings were amorphous. Only slight differences between the microhardness and adhesion values of the coatings with small and large bilayer period Λ were found. The experiments also showed that the multilayered coatings improved the corrosion resistance of the uncoated alloy and reduced the amount of ion release in artificial body fluids.     

生物医用NiTi形状记忆合金腐蚀研究进展

镍钛形状记忆合金(NiTi-SMA)具有较好的耐腐蚀和机械性能,在口腔和临床医学中有着大量而广泛的应用。NiTi-SMA腐蚀后释放Ni²⁺会引发细胞毒性和过敏反应,进一步提高NiTi-SMA的耐蚀性是目前生物医学材料领域发展的核心之一。本文对近年来国内外有关口腔医学和临床医学中常用NiTi-SMA的腐蚀研究现状进行了总结,同时也对NiTi-SMA增材制造及表面改性技术进行了评述,以期为开发高性能抗腐蚀生物医用NiTi-SMA提供一定的指导意义。     

Li掺杂Ba(Ti1/7Sn1/7Zr1/7Hf1/7Nb1/7Ga1/7Li(1/7-x))O3高熵陶瓷的制备及介电性能研究

近年来,在高熵合金基础上发展起来的高熵陶瓷逐渐引起了研究者的广泛关注,其出现为开发高性能的无机非金属材料提供了新的设计思路。本文采用固相法制备了BaMO3基钙钛矿型高熵陶瓷Ba(Ti1/7Sn1/7Zr1/7Hf1/7Nb1/7Ga1/7Li(1/7-x))O3 (x = 0, 2.3%, 5.3%, 8.3%, 11.3%),并研究了Li含量对高熵陶瓷物相结构、微观形貌及介电性能的影响。结果表明,Li含量对陶瓷结构的影响不大,陶瓷均保持立方钙钛矿结构,且无杂相产生;陶瓷的晶粒尺寸相对较均匀。当x = 0时,即B位七元等摩尔比Ba(Ti1/7Sn1/7Zr1/7Hf1/7Nb1/7Ga1/7Li1/7)O3高熵陶瓷,其介电常数达到了最大值2920 (@100 Hz),相较于已报道的不掺Li的六元高熵钙钛矿陶瓷Ba(Ti1/6Sn1/6Zr1/6Hf1/6Nb1/6Ga1/6)O3提升了近50倍。     

MOCVD growth and characterizations of BxAl1−xAs and BxAl1−x−yInyAs alloys

Zinc-blende B_xAl_1−xAs and B_xAl_1−x−yIn_yAs alloys have been grown on exactly oriented (0 0 1)GaAs substrates by low pressure metalorganic chemical vapor deposition (LP-MOCVD). The influence of susceptor coating, growth temperature and gas-phase boron mole fraction on boron incorporation into AlAs has been comprehensively investigated. It has been found that boron incorporation into AlAs could be enhanced and the optimal growth temperature range of B_xAl_1−xAs alloys changed from 580 °C to 610 °C when SiC-coated graphite susceptors were replaced by the non-coated ones. In this study, the maximum boron composition x of 2.8% was achieved for the pseudomorphically strained B_xAl_1−xAs alloys. AFM measurements show that RMS roughness of B_xAl_1−xAs alloys increased sharply with the increase of gas-phase boron mole fraction. Raman spectra of B_xAl_1−xAs alloys show a linear increase of the BAs shift with boron composition x. Based on BAlAs deposition, bulk B_xAl_1−x−yIn_yAs (x = 1.9%) quaternary alloy was grown lattice-matched to GaAs successfully. Moreover, 10-period BAlAs/GaAs and BAlInAs/GaAs MQW heterostructures were also demonstrated.     

Hydrothermal synthesis of superconductors Ba1−xKxBiO3 and double perovskites Ba1−xKxBi1−yNayO3

Superconductors Ba_1−xK_xBiO₃ and body-centered double perovskites Ba_1−xK_xBi_1−yNa_yO₃ have been selectively synthesized by a facile hydrothermal route. The appropriate ratio and adding sequence of initial reagents, alkalinity, reaction temperature and time are the critical factors that influence the crystal growth of the compounds. The purity and homogeneity of the crystals were detected by the ICP, SEM, EDX and TEM studies. Magnetic measurements show that the superconducting transition temperatures T_C of Ba_1−xK_xBiO₃ decrease from 22 K (for x = 0.35) to 8 K (for x = 0.55) with increasing the K doping level.     

Magnetic phase diagrams of the TbRh2−xPdxPdxSi2 and TbRu2−xPdxSi2 systems

The a.c. susceptibility and high field magnetization on TbRh_2−xPd_xPd_xSi₂ and TbRu_2−xPd_xSi₂ compounds were investigated up to 140 kOe. The (T,x) magnetic phase diagrams were determined. For both systems, an increase in the Pd content causes a decrease in the Néel temperature and changes the magnetization curves.     

High strength and good ductility of casting Al-Cu alloy modified by PrxOy and LaxOy

A modified Al-Cu alloy with high tensile strength and ductility of about 574.0 MPa and 10.4%, respectively, was obtained by adding multiple rare earth oxides (Pr_xO_y and La_xO_y) as modifier. Compared with the unmodified Al-Cu alloy, the tensile strength and ductility of the modified sample were increased by 24.3% and 42.5%, respectively. The improvement both in the strength and ductility may attribute to the finer crystal grains and dendrites, more homogeneously distributed θ′ phase precipitates and the intermetallic compounds formed at the crystal grain boundaries as well as in the space of the dendrites.     

Si3N4/Ti/Cu/Ni/Cu/Ti/Si3N4二次部分瞬间液相连接强度

采用Ti/Cu／Ni中间层对Si3N4陶瓷进行二次部分瞬间液相(PTLP)连接，研究连接工艺参数对Si3N4／Ti/Cu／Ni连接强度的影响，同时研究了连接强度随试验温度的变化规律。结果表明，在该试验条件下，室温连接强度随着二次连接温度的提高和二次保温时间的延长而提高，改变连接工艺参数对Si3N4／Ti/Cu／Ni二次PTLP连接界面反应层厚度无明显影响；连接强度在试验温度400℃时达到最大，随后随试验温度升高，连接强度降低，但在800℃前，其高温强度具有很好的稳定性。     

Structural analysis of sputtered (W-C)1−xMx (MFe, Co) films with 0x0.20

Structural characterization of (W-C)_1-xM_x (MFe, Co) films with 0x0.20 was carried out using electron probe microanal ysis (EPMA), X-ray diffraction (XRD) and transmission electron microscopy-electron diffraction (TEM-ED). The results showed that the structure of these films depends on the percentage of iron and cobalt and becomes amorphous with increasing content of these elements. The microstructure of the crystalline coatings was found to be composed of small grains of β-WC_1-x with a high number of defects. A strong β-WC_1-x[311] texture was observed for iron and cobalt contents around 5.5 at.%. The films richer in iron and cobalt showed typical amorphous XRD and ED patterns, exhibiting two broad peaks and two wide diffuse rings respectively. Moreover, bright-field analysis revealed fairly contrasted images, the structure of these films being difficult to resolve.