机械润滑材料MAX相氮化物的制备及其性能研究

发布时间：2018-06-19 15:29

本文选题：MAX相 + Ti2A　；参考：《南华大学》2015年硕士论文

【摘要】：机械润滑材料MAX相氮化物Ti2Al N和Ti4Al N3材料,其晶体结构是由Tin+1Nn片层与Al原子面交替堆垛排列而成,这种层状结构和独特的价键特性,使其具有较好的自润滑性能和耐辐照损伤性能,又具备金属和陶瓷的优异性能,因而是潜在的机械润滑材料和核燃料包壳结构材料。本文首先通过微波烧结法合成了Ti2Al N和Ti4Al N3材料。在微波烧结条件下,制备得到纯的带有取向生长的Ti2Al N,研究了烧结工艺和反应路径,以及取向生长机理;Ti4Al N3,则研究了在微波烧结条件下烧结工艺和初始原料对最终成相的影响。最后,将制得的纯相,再采用放电等离子体法以适当的烧结工艺分别对Ti2Al N和Ti4Al N3致密化烧结成型。研究了其微观结构,物理性能,摩擦磨损性能,并尝试用HF腐蚀Ti2Al N和Ti4Al N3材料;同时对合成的Ti2Al N和Ti4Al N3材料开展了在70 ke V He离子束辐照实验研究,从微观结构及模拟方面探究了其辐照损伤结构演变。在室温测得的Ti2Al N和Ti4Al N3这二种致密化材料的基本物理性能与文献报道相吻合。Ti2Al N和Ti4Al N3这二种材料在稳定磨损阶段的摩擦系数均相近,其摩擦磨损机制类似。在Ti2Al N中没有取向的表面的耐磨性相对于有取向的表面要好。此外,Ti4Al N3的摩擦磨损性能要优于Ti2Al N。研究发现Ti4Al N3比Ti2Al N相在HF中更为稳定,其中Ti4Al N3相有望用来制备二维氮化物片层材料。利用70 ke V He离子对所合成的Ti2Al N和Ti4Al N3材料开展了辐照损伤实验研究。发现目前报道的MAX相在辐照条件下的结构转变机制不能解释辐照后Ti2Al N和Ti4Al N3的结构转变。在低剂量下,Ti2Al N和Ti4Al N3基本相似,它们的电子衍射模拟结果与实验结果均并不相符。在较高剂量下,不同于Ti2Al N的是,Ti4Al N3的微观结构并没有发生明显的退化,仍然保持了在较低剂量辐照下的微观结构,并不形成孪晶的FCC结构。
[Abstract]:Mechanical lubricating materials Max phase nitride Ti2AlN and Ti4AlN3, the crystal structure of which is composed of Tin 1Nn lamellar alternating stacking with Al atomic surface, this kind of layered structure and unique valence bond properties. It is a potential mechanical lubricating material and nuclear fuel cladding structure material because it has good self-lubricating property, radiation damage resistance and excellent performance of metal and ceramics. Ti2AlN and Ti4AlN3 materials were synthesized by microwave sintering. Pure Ti 2AL N with orientation growth was prepared under microwave sintering condition. The sintering process, reaction path and orientation growth mechanism of Ti 4AL N 3 were studied. The effects of sintering process and initial raw materials on the final phase formation were studied. Finally, the pure phase was prepared and densified sintering of Ti _ 2AL _ N and Ti _ 4AL _ 3 was formed by using discharge plasma method and appropriate sintering process, respectively, in which Ti _ 2AL _ N and Ti _ 4AL _ 3 were densified respectively. The microstructure, physical properties, friction and wear properties of Ti _ 2AL _ N and Ti _ 4AL _ N _ 3 materials were studied, and the synthesized Ti _ 2AL _ N and Ti _ 4AL _ N _ 3 materials were irradiated by 70ke V he ion beam. The evolution of radiation damage structure was investigated from microstructure and simulation. The physical properties of Ti _ 2AL _ N and Ti _ 4AL _ 3 densified materials measured at room temperature are in agreement with those reported in literature. The friction coefficients of Ti _ 2AL _ N and Ti _ 4AL _ 3 are similar at the stable wear stage, and their friction and wear mechanisms are similar. The wear resistance of non-oriented surfaces in Ti _ 2AL N is better than that of oriented surfaces. In addition, the friction and wear properties of Ti _ 4AL _ N _ 3 are better than that of Ti _ 2AL _ N. It is found that Ti _ 4AL _ 3 is more stable in HF than Ti _ 2AL _ N, among which Ti _ 4AL _ 3 is expected to be used to prepare two-dimensional nitride laminates. The irradiation damage of Ti _ 2AL _ N and Ti _ 4AL _ 3 materials synthesized by 70ke V he ion was studied experimentally. It is found that the structure transition mechanism of MAXphase under irradiation condition can not explain the structural transformation of Ti _ 2AL _ N and Ti _ 4AL _ 3 after irradiation. The electron diffraction simulation results of Ti _ 2AL _ N and Ti _ 4AL _ N _ 3 are not consistent with the experimental results. At higher doses, the microstructure of Ti4AlN3, which is different from Ti2AlN, does not degenerate obviously. It still maintains the microstructure of Ti4AlN3 at lower doses and does not form a twin FCC structure.
【学位授予单位】：南华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB34

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