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使用Ag-Cu-Ti钎料以及Ag-Cu-Ti+BAg72Cu复合钎料对Al2O3弥散强化铜与T2铜进行真空钎焊,研究了钎焊温度和保温时间对钎焊接头组织和性能的影响。结果表明,温度过低,钎料与母材相互冶金作用较弱,接头性能较差;温度过高或保温时间过长,钎料向弥散强化铜中毛细渗入严重,焊缝中出现孔洞,接头强度也下降。利用Ag-Cu-Ti+BAg72Cu复合钎料进行钎焊能有效提高接头强度。 相似文献
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电真空应用中,要求高纯氧化铝与金属钛的连接接头不仅要有较好的强度,还要有高的气密性.用Ag-Cu-Ti钎料钎焊高纯氧化铝陶瓷与金属钛,钎焊温度为825~875℃,保温时间为15~20min,陶瓷表面为烧结自然表面时,钎焊接头抗剪强度可达到100MPa以上,连接温度过低或过高,保温时间过短或过长均对接头强度不利.陶瓷表面研磨后,接头强度降低.钎料厚度在60μm或105μm对接头强度的影响不大.接头由Al2O3/反应层(Cu,Al,Ti,0)/Ag Cu-Ti化合物/α-Ti(Cu)/Ti构成.反应层主要以Cu3Ti3O和Cu4Ti为主. 相似文献
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采用97(72Ag-28Cu)-3Ti活性钎料钎焊了Diamond/Cu复合材料和Al2O3陶瓷,研究了主要钎焊条件如钎焊温度和保温时间对接头强度的影响.结果表明,钎焊过程中Ti元素易聚集在金刚石颗粒周围并形成TiC化合物层.TiC化合物的形貌与Diamond/Cu钎焊接头剪切强度有密切关系,金刚石表面生长适当厚度的TiC化合物层能增强钎焊接头的剪切强度,但如果TiC为颗粒状或TiC化合物层生长过厚,将削弱钎焊接头的剪切强度.钎焊接头的最大剪切强度可达117 MPa. 相似文献
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采用Al5Si28Cu1.5Ti钎料,在真空钎焊炉中钎焊SiCP为55%的SiCP/Al6061铝基复合材料,钎焊温度580℃,研究了保温时间对接头组织性能的影响。结果表明,活性钛元素提高了钎料对复合材料的润湿性,保温40 min接头的组织性能最好,剪切强度为84 MPa。 相似文献
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采用BAg72Cu共晶钎料对奥氏体不锈钢与纯铜的真空钎焊工艺进行研究.通过剪切试验、光学显微镜观察、扫描电镜及能谱分析等手段研究了钎焊温度和保温时间对钎焊接头组织和性能的影响.试验表明,钎缝中心区为AgCu共晶组织,两侧界面反应区为铜基固溶体,钎焊温度对钎焊接头的组织和性能影响明显,而保温时间对其影响不明显.当钎焊温度865℃、保温时间10min时,剪切强度最高,达到160 MPa.钎焊温度过低时,冶金作用较弱,接头强度较低;钎焊温度过高时,钎料流淌较多,接头强度也较低.以865℃为钎焊温度,改变保温时间,在10~45 min保温时间内接头的剪切强度变化不大. 相似文献
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电真空应用中,要求高纯氧化铝与无氧铜的连接接头具有较高的强度和气密性.采用Ag-Cu-Ti活性钎料直接钎焊高纯氧化铝陶瓷与无氧铜,研究了钎焊温度和保温时间对接头组成、界面反应以及接头抗剪强度的影响,研究了铜基体材料对钎焊接头组织和界面反应的影响.钎焊温度850~900℃,保温时间20~60 min时,接头抗剪强度接近或达到90 MPa.钎焊工艺参数偏离上述范围时,接头抗剪强度较低.接头由Cu/Ag(Cu),Cu(Ag,Ti)/Cu3Ti3O(TiO2)/Al2O3组成,反应层以Cu3Ti3O为主,个别工艺条件下有一定量的TiO2生成,铜基体视工艺条件的不同对钎焊接头组织有一定影响. 相似文献
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在钎焊温度为780~900℃,钎焊时间为2~30 min的条件下,采用Ag-28Cu钎料对TC4钛合金进行了真空钎焊试验。利用金相显微镜、扫描电镜及能谱仪对接头微观组织进行了研究。结果表明,接头形成3个反应区:扩散区Ti_2Cu+Ti(s.s)、界面反应区Ti_2Cu/TiCu化合物以及钎缝中心区的Ag(s.s)+Cu(s.s)。随着钎焊温度的提高和保温时间的延长,扩散区及界面层的厚度增加,但过高的工艺参数会导致钎料流失从而使钎缝宽度降低。在钎焊温度为820℃,保温时间为10 min时,钎焊接头的抗剪强度最高,为121 MPa。 相似文献
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M. Balaceanu V. Braic A. Kiss A. Vladescu C. Vasilescu O. Muresanu 《Surface & coatings technology》2008,202(11):2384-2388
Results on the deposition and characterization of TiOxNy/ZrOxNy 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. 相似文献
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本文运用溶胶-凝胶燃烧法合成了双钙钛矿型LaNixCo1-xO3(LNCO)纳米材料,利用粉末冶金和热挤压技术制备了相应的Ag/LNCO触点材料及元件样品。重点考察了不同Ni、Co含量对Ag/LNCO触点材料微观结构、物相组成、物理性能、力学性能及电寿命服役能力的影响,对其电弧侵蚀失效行为进行了研究,并与SnO2粉体增强Ag基触点材料进行对比。结果表明:溶胶凝胶法合成的LNCO纳米颗粒粒径为20-30 nm,经粉末冶金工艺制备的Ag/LaNi0.5Co0.5O3触点材料电学性能和电寿命都优于Ag/SnO2触点材料,其电阻率低至2.10 μΩ?cm,电寿命性能达到51287次。表明Ag/LaNi0.5Co0.5O3触点材料性能较佳,是一种可以取代Ag/CdO的新型触点材料。 相似文献
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Qi Wang Xiaomin RenLijuan Zhang Yue YangTianhe Li Hui HuangYongqing Huang Shiwei Cai 《Journal of Alloys and Compounds》2011,509(18):5631-5636
Zinc-blende BxAl1−xAs and BxAl1−x−yInyAs 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 BxAl1−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 BxAl1−xAs alloys. AFM measurements show that RMS roughness of BxAl1−xAs alloys increased sharply with the increase of gas-phase boron mole fraction. Raman spectra of BxAl1−xAs alloys show a linear increase of the BAs shift with boron composition x. Based on BAlAs deposition, bulk BxAl1−x−yInyAs (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. 相似文献
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Hailong ZhaoDongming Yao Feng QiuYumei Xia Qichuan Jiang 《Journal of Alloys and Compounds》2011,509(5):L43
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 (PrxOy and LaxOy) 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. 相似文献
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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。 相似文献
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CAD/CAE/CAM/PDM应用分析 总被引:1,自引:0,他引:1
分析了CAD/CAE/CAMP/PDM的作用和关系,介绍了常用CAD/CAE/CAMPDM软件及选型方法,为企业建立和应用CAD/CAE/CAM/PDM提供了依据。 相似文献
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Ganghua ZhangGuobao Li Fuqiang HuangFuhui Liao Kuo LiYinxia Wang Jianhua Lin 《Journal of Alloys and Compounds》2011,509(41):9804-9808
Superconductors Ba1−xKxBiO3 and body-centered double perovskites Ba1−xKxBi1−yNayO3 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 TC of Ba1−xKxBiO3 decrease from 22 K (for x = 0.35) to 8 K (for x = 0.55) with increasing the K doping level. 相似文献
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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。 相似文献
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Toshiki Tsubota Teruhisa Ohno Norihisa Shiraishi Yuji Miyazaki 《Journal of Alloys and Compounds》2008,463(1-2):288-293
Thermoelectric properties of Sn1−x−yTiy SbxO2 ceramics were investigated in detail. The addition of Sb into SnO2 matrix increased the electric conductivity, σ. The increase in the σ value should be caused by the increase in the carrier concentration. The Seebeck coefficients of all the samples were negative, which means that these samples have n-type conduction. The samples of this study have porous structure. The maximum Z value of all the samples measured in this study was 2.4 × 10−5 K−1. 相似文献