不锈钢纤维烧结毡在微生物燃料电池阳极中的研究进展

详细介绍了不锈钢纤维烧结毡在微生物燃料电池阳极中的应用现状及前景.不锈钢纤维烧结毡是采用微米级的不锈钢纤维经无纺铺制、叠配、真空烧结而成.它是由不同丝径的纤维形成的一种三维金属多孔材料,具有机械强度高、渗透性能好、导电性好、吸附能力强、耐腐蚀、耐高温、易加工等优点,在高效微生物燃料电池阳极材料方面呈现出了巨大的应用价值...     

Preparation of oriented linear copper fiber sintered felt and its performance

Long metal fibers were manufactured in horizontal lathe with a multi-tooth tool. Based on the coarse antler surface structure of copper fibers, a new sintering technology was put forward to manufacture a kind of oriented linear copper fiber sintered felt. The sintering mechanism of oriented linear copper fiber sintered felt was studied. Compared with sintered copper-wire felt, the characteristics of sintered copper-fiber felts were analyzed in details. Owing to the coarse antler surface structure of copper fibers, oriented linear copper-fiber felt was sintered under the condition ofmicro/nano scale range, and copper fibers easily bonded together in the sintering process. Microchannels with micro-scale coarse antler surface structure were constructed. These characters give oriented linear copper fiber felt some new merits： high filtration accuracy, high flow capability, low resistance loss, good capability to resistance pressure, stable and uniform pore, high specific surface area. The properties of oriented linear copper fiber sintered felt were analyzed.     

不锈钢纤维多孔材料拉伸性能研究

以316L不锈钢纤维毡为原料,采用不同的烧结工艺,制备出孔隙度为70%~95%的不锈钢纤维多孔材料,研究了纤维丝径、孔隙度、烧结温度和保温时间对其拉伸性能的影响。研究表明,不锈钢纤维多孔材料的拉伸过程主要分为3个阶段:弹性阶段、塑性变形阶段和断裂阶段。纤维越细,多孔材料的抗拉强度越高;随着孔隙度的增加,多孔材料的抗拉强度逐渐降低;提高烧结温度或延长保温时间,均会提高多孔材料的抗拉强度。     

陶土对铸钢消失模涂料烧结性的影响

采用阿基米德法测试烧结试样密度,研究了陶土对铸钢消失模涂料烧结性的影响。结果表明,随着陶土含量和烧结温度的增加,试样体积密度都有增大趋势。陶土含量为5%时,试样在1550℃时密度显著增大,符合铸钢消失模涂料要求。另外,进行现场浇注试验,对涂片层断面进行扫描电镜分析,涂片层断面与钢水接触部分烧结良好,耐火骨料连成整片,阻止钢水进一步渗透,使涂料烧结壳从铸件表面自动剥离。     

Ag-Cu固溶体颗粒制备及低温烧结互连接头性能

通过液相化学还原法制备Ag-Cu固溶体纳米颗粒,采用低温热压烧结工艺制备“三明治”结构的互连接头.采用X射线衍射仪对所制备的Ag-Cu固溶体纳米颗粒及烧结体进行物相表征;采用能谱仪对所制备的Ag-Cu固溶体纳米颗粒的元素进行表征;采用纳米粒度仪对Ag-Cu固溶体纳米颗粒粒径进行表征;通过扫描电子显微镜对互连接头的烧结组织和剪切断面形貌进行观察,分析颗粒烧结情况和互连接头断裂模式. 结果表明,通过液相化学还原的方法实现了室温下铜在银中的超饱和固溶,其中Ag原子分数为62.29%,Cu原子分数为37.71%,远超常温下常规块体材料的固溶度. 所制备的纳米颗粒在250 ℃以内保持相对稳定的固溶体相,260 ℃时发生相分离. 当烧结温度为300 ℃、烧结压力20 MPa时,所获得的互连接头具有优异的力学性能,平均抗剪强度达到105 MPa,且烧结组织呈现完整的脉络状,剪切断面全部为韧窝状,属于韧性断裂.     

Rapid sintering of ultrafine WC–Ni cermets

Using high-frequency induction-heated sintering (HFIHS), cermets of WC–xNi (x = 8, 10, and 12 wt.%) were consolidated to a density of about 98%. The sintered samples had WC grain size of 300 nm. The hardness was significantly higher than that obtained with conventionally sintered WC–Co and WC–Ni cermets without a reduction in fracture toughness.     

用于大面积芯片互连的纳米银膏无压烧结行为

文中采用化学还原法制备出一种可以用于低温烧结的纳米银膏,通过对低温无压烧结纳米银焊点的组织结构、力学性能和失效模式进行了分析,系统地讨论了无压烧结焊点中烧结银组织的渐进性组织演变规律,获得了互连焊点尺寸对烧结银连接性能和可靠性的影响.在烧结温度250℃,保温时间1 h的条件下,焊点面积小于等于3 mm×3 mm时,无压...     

Corrosion Behavior of Sintered 316L Stainless Steel Fibre Porous Felt

烧结金属纤维多孔材料是一种优质高效新型功能材料。通过浸泡试验、动电位极化扫描、金相分析及SEM扫描电镜等试验对316L不锈钢纤维多孔材料的腐蚀机理进行了系统的研究。研究发现:晶界腐蚀和蚀坑对材料的腐蚀过程均有影响;纤维烧结点处比纤维杆处耐蚀;随着孔隙率的增大,纤维毡的腐蚀失重量增大,腐蚀程度更严重。     

铁粉烧结圆环开式热锻综合试验研究

采用烧结圆环开式热锻试验方法,综合考察了中碳合金钢粉烧结材料热锻过程的摩擦因子、断裂应变极限和致密情况。提出了一种烧结－喷丸、－热锻新工艺、用以有效提高材料的断裂应变极限和锻后材料的表面密度。     

基于SPS烧结的M42/45钢双金属接头及性能

利用放电等离子烧结技术(SPS)研究了M42粉末高速钢/45钢双金属连接技术,分析了连接接头的界面形貌,测试了连接接头的界面结合强度.结果表明:在970℃×10 min×70 MPa烧结工艺下,可一次性实现M42粉末高速钢的烧结及其与45钢的连接;接头的M42粉末冶金高速钢部分,显微组织均匀,碳化物细小、无偏析,经工艺1180℃×5 min×550℃×1 h热处理后,硬度达到67.36 HRC;M42/45钢连接接头组织致密且均匀,界面两侧有元素扩散,属冶金结合,界面结合强度可达到550 MPa.     

Electrochemical characterization of vacuum sintered copper alloyed austenitic stainless steel

The aim of this work is the study of the electrochemical behaviour and corrosion resistance of copper alloyed vacuum sintered stainless steel. The presence of copper can improve the passivability of sintered stainless steel and, as a consequence, the corrosion resistance; moreover, vacuum sintering allows materials with good chemical and mechanical properties to be produced, avoiding the interaction between the metal and the sintering atmosphere. Microstructural characterization was carried out: copper evaporation during sintering and a different solubility of copper in AISI 304L and AISI 316L were indicated. This last result was related to the surface oxides stability of the steels in the sintering condition. The electrochemical characterization in an acid environment showed different behaviour as a function of the copper amount and of its presence as solid solution. These results were compared with similar measurements of wrought materials or samples sintered in a nitrogen-containing atmosphere.     

除尘灰对Si质消失模铸钢涂料烧结性的影响

使用BST401抗折弯仪测试烧结试样的抗弯强度,研究除尘灰对Si质消失模铸钢涂料烧结特性的影响.结果表明,随着除尘灰含量增加和烧结温度提高,试样的抗弯强度有增大的趋势,当除尘灰含量为4％、在1 500℃烧结时,试样的抗弯强度显著增大,符合消失模铸钢涂料的要求.经对现场浇注试样进行涂层断面扫描电镜(SEM)分析,发现涂层断面与钢液接触部分烧结良好,耐火骨料连成整片,因此可实现涂料烧结壳从铸件表面自动剥离.     

铜颗粒低温烧结技术的研究进展

金属纳米材料因具有良好的导电导热性以及能够在较低温度下进行烧结，是功率器件在高温高压高频等工作环境下服役所需的关键电子封装材料之一.文中对应用于功率器件封装领域的铜颗粒实现烧结的研究进行了综述，阐明了目前通过铜颗粒烧结技术实现低温键合的研发背景.从铜颗粒烧结材料的制备、工艺参数和还原方法等关键影响因素出发，讨论、归纳了基于不同烧结机理的低温烧结铜颗粒材料接头的力学性能和电学性能.此外，介绍了铜颗粒烧结技术在贴片封装和全铜互连领域中应用的优良特性.通过对该领域研究成果的分析，结果表明，目前铜烧结材料仍然受到氧化问题的挑战，需要进一步在接头性能的精准调控方面深入研究.     

消失模铸钢涂料耐火骨料烧结性的研究

以石英粉和铝矾土组成复合耐火骨料,在不同温度下进行烧结,使用BST401抗折弯仪测试烧结试样的抗弯强度,研究不同配比的耐火骨料的烧结性。研究表明,随着复合骨料中铝矾土含量的增加和烧结温度的升高,试样的抗弯强度都有增大的趋势。当铝矾土含量为60%、石英粉含量为40%、试样在1500℃时抗弯强度显著增大。并对烧结试样进行扫描电镜(SEM)分析,试样烧结良好,符合消失模铸钢涂料耐火骨料的要求。     

溶液浸渍法制备镍金属布的研究

以涤纶布和粘胶纤维布为基体,采用溶液浸渍法并在氢气气氛下还原烧结制备了镍金属布。用扫描电子显微镜、X射线衍射研究了不同工艺对镍金属布显微结构和相成分的影响,并通过TG-DTA分析研究了还原烧结过程中的反应机制。结果表明：选用粘胶纤维布作为基体,在NiCl2溶液中浸渍后,置于氢气气氛中900 ℃还原烧结,即可制备出连续、完整、柔韧性较好的镍金属布。     

多尺度纳米银烧结接头连接强度及塑性

以低温烧结连接使用的纳米银膏为研究对象,通过计算获得银膏中纳米银颗粒与微米银颗粒的最佳配比并制备复合银膏. 研究了银膏中不同溶剂对接头孔隙形成的影响,对比了纳米银膏与复合银膏硬度、弹性模量及塑性因子. 结果表明,在250 ℃的烧结温度下松油醇和酒精的混合有机溶剂有利于烧结接头质量的提升,其烧结层孔隙率明显低于乙二醇制备的复合银膏烧结接头. 与纳米银膏烧结接头相比,复合银膏烧结层压痕面积较大,硬度与弹性模量较低. 当烧结时间为10 ~ 30 min时,复合银膏烧结层塑性因子高于纳米银膏烧结层.     

Effect of titanium addition on mechanical properties of Mo-Si-B alloys

In this study, we investigated the effect of titanium addition on microstructure and mechanical properties in Mo-Si-B alloys. The Mo-Ti-Si-B alloy (Mo-3.9Ti-3Si-1B, wt%), which has α-Mo, Mo₃Si, Mo₅SiB₂ and TiO₂ phases_, was fabricated by a powder metallurgy (PM) method. The starting materials were pulverized by using a high-energy ball milling and the resultant powder was subjected to a reduction process followed by cold isostatic pressing (CIP) compaction and pressureless sintering. In the microstructure, intermetallic compound phases were uniformly distributed in the α-Mo matrix. Some titanium atoms solved into the α-Mo matrix and the others formed a TiO₂ phase caused by reaction with oxygen at the grain boundary. Fracture toughness of the Mo-Ti-Si-B sintered body was recorded as 10.42 MPa·m^1/2, which is lower than that of the Mo-Si-B sintered body without addition of titanium. In the Mo-Ti-Si-B sintered body, the fracture mode is similar to the Mo-Si-B sintered body where intergranular fracture through the Mo grain boundary and transgranular fracture cross the intermetallic compound phase. The decrease of fracture toughness is due to the relatively large TiO₂ at the grain boundary, promoting intergranular fracture.     

掺Li量和烧结温度对铬酸镧烧结行为的影响

研究了用Pechini法制备掺Li铬酸镧超细粉体在烧结过程中掺Li量和烧结温度对粉体烧结行为及烧结体组织的影响.结果表明,在相同烧结温度下,LaCr1-yLiyO3烧结体收缩率随掺Li量的增加而升高;当掺Li量y为0.2时收缩率达到最大;此后随着掺Li量增加而降低.就相同掺Li量的烧结体而言,烧结温度越高组织越致密.致密烧结体的断口特征为穿晶和沿晶混合断裂,这表明晶界结合强度接近晶内.烧结过程中晶粒不断合并、长大,其长大机制为台阶方式.     

Mechanical properties of β-SiC fabricated by spark plasma sintering

The consolidation of SiC nanopowder synthesized by the mechanical alloying method was subsequently accomplished by spark plasma sintering of 1700 °C for 10 min under an applied pressure of 40 MPa. The SiC sintered compact with relative density of 98% consisted of nano-sized particles smaller than 100 nm. This phenomenon resulted in the ordering process of stacking disordered structure formed by mechanical alloying. In this work, the effect of grain size and relative density on the mechanical properties were studied. The mechanical properties of sintered compacts were evaluated and compared with the reference samples fabricated from the commercial SiC powder (β-SiC, 0.3 μm, IBIDEN Co., Gifu, Japan) with sintering additive (B–C mixture). The Vickers hardness and bending strength of those sintered compacts increased with the increment of the density. However, the mechanical properties were lower than those of reference samples in case of lower density, even though the mechanical property was close to that of reference sample in case of higher density. This phenomenon was considered for the difference of bond strength between grains because those sintered compacts were fabricated without any sintering additives, while those reference samples were fabricated by accelerating the grain bonding with a sintering additive of B–C mixture. In other words, those results indicated that the effect of sintering additive affected on mechanical properties directly. This paper was presented at the International Symposium on Manufacturing, Properties, and Applications of Nanocrystalline Materials sponsored by the ASM International Nanotechnology Task Force and TMS Powder Materials Committee on October 18–20, 2004 in Columbus, OH.     

Microwave sintering of large size pieces with complex shape

In this study, large size pieces of kaolin with a complex shape were successfully sintered in a microwave multimode cavity. The challenge was to obtain a sample homogeneously sintered on a large surface. For this purpose, prior to sintering, a finite element modelling study was carried out to determine the optimal experimental set-up configuration permitting to have an electromagnetic field as homogenous as possible around the sample. In this case, it was pointed out that the hybrid heating configuration (use of susceptors) was the most suitable configuration.The samples experimentally obtained were structurally and mechanically characterized. Therefore, it was highlighted that the microwave sintered samples present a microstructure and mechanical properties similar to those of samples conventionally processed for a lower sintering temperature.Finally, the microwave sintering permit to significantly reduce the energy consumption required for the production of sintered ceramic pieces, which is crucial for sustainable development.