镍多孔结构中微纳米粒子的烧结与腐蚀

发布时间：2018-02-04 03:43

  本文关键词： 多孔镍 微米粒子 纳米粒子 烧结 腐蚀　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：多孔金属材料不仅拥有金属材料的导电性强、强度高、韧性好等金属特性,还具备了体积密度低、比表面积高等优点。这些优良的特性使多孔金属材料得到了广泛的应用。其中多孔镍在催化领域可作为催化剂或载体,在锂空气电池、超级电容器等能源领域可作为电极载体,在过滤分离行业可用于气-固分离等应用使其成为研究的热点。多孔金属材料的制备方法多样,但都存在各自的优缺点,将多种制备方法结合可以更好地控制多孔材料的制备过程和孔结构。本文分别以微米粒子和纳米粒子为原料,采用烧结法和腐蚀造孔法相结合的方法来制备多孔镍金属材料。镍和铝纳米粒子采用直流电弧氢等离子体法制备,并用TEM、XRD等方法进行表征,对于多孔体采用SEM、XRD、DTA、BET等表征方法进行分析。实验结果表明,A1的质量分数为16.7%的Ni/A1纳米粒子,在氩气保护的条件下800℃烧结的产物为NiAl金属间化合物,形成的孔结构呈融化不规则状；而同样成分的微米粒子烧结产物为Ni2Al3,形成A1微米粒子消耗坍陷的孔结构。单一的烧结方法可以形成孔结构,而辅以化学腐蚀法则使孔结构更具可控性。烧结温度、腐蚀条件是决定孔结构的关键因素,经过500℃烧结并利用NaOH溶液腐蚀的纳米粒子Ni/Al烧结体可以获得纳米多孔镍金属材料,其孔径在几十至几百纳米,比表面积为18.948m2/g,相同条件下的微米粒子Ni/Al烧结体可以获得均匀的、平均孔径约为401μm的圆孔结构。此外,本文还对多孔镍制备过程中的烧结行为和腐蚀行为进行了分析,发现纳米粒子Ni/Al烧结体的体积膨胀率低于相同成分的微米粒子烧结体的体积膨胀率；纳米粒子烧结体相比微米粒子烧结体,更难被NaOH溶液腐蚀；且无论粒子粒度如何,烧结温度越高,腐蚀后多孔镍中残留的Al含量越高。对于微米粒子Ni/A1烧结体,在800℃烧结时,Al含量越多,烧结后的体积膨胀率越大,形成的孔径和孔个数增多,但当Al含量达到一定程度时(质量分数约40%以上),由于过量的Al堵塞表面孔洞,形成粗糙的表面结构。
[Abstract]:Porous metal materials not only have high electrical conductivity, high strength, good toughness and other metal characteristics, but also have low bulk density. These excellent properties make porous metal materials widely used. Porous nickel can be used as catalyst or carrier in lithium-air batteries in the field of catalysis. Supercapacitors and other energy fields can be used as electrode carriers in the filtration separation industry can be used in gas-solid separation applications make it a research hotspot. The preparation methods of porous metal materials are various. However, each has its own advantages and disadvantages. The preparation process and pore structure of porous materials can be better controlled by combining various preparation methods. In this paper, micron particles and nano-particles are used as raw materials, respectively. The porous nickel metal materials were prepared by sintering method and corrosion pore-forming method. The nickel and aluminum nanoparticles were prepared by DC arc hydrogen plasma method and characterized by TEM XRD and so on. The Ni/A1 nanoparticles with a mass fraction of 16.7% were analyzed by means of SEM-XRDX DTA-BET and other characterization methods. The product sintered at 800 鈩，

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