添加Ti+Al或Ti₃Al对TiB₂-Fe金属陶瓷结构和性能的影响

【作者】 沈明；

【导师】 王零森； 高荣根；

【作者基本信息】 中南大学 ， 材料工程， 2003， 硕士

【摘要】 金属间化合物Ti₃Al、Ni₃Al，NiAl，FeAl等，尤其是钛合金—Ti₃Al，由于具有与TiB₂陶瓷基体一致的晶格结构和相近的晶格参数，均为密排六方晶格，有望改善TiB₂陶瓷材料的高温性能。 本文通过运用扫描电子显微镜（SEM）、能谱分析和X-衍射等方法系统研究了采用气氛保护烧结的加入了金属Ti和Al或金属间化合物Ti₃Al的TiB₂-Fe系金属陶瓷的组织结构、元素的分布以及相组成，分析了它们在TiB₂-Fe系金属陶瓷中的作用及反应机理。在加入一定量的金属3Ti+Al或金属间化合物Ti₃Al的TiB₂-Fe金属陶瓷中均形成了TiB₂+TiC双硬质相结构，与TiB₂-Fe金属陶瓷比较，TiB₂晶粒略大，并形成了多种元素组成的合金粘接相。在TiB₂-Fe金属陶瓷加入3Ti+Al，没有反应合成Ti₃Al化合物，Ti₃Al与TiB₂没发现固溶现象，Ti₃Al有一部分在烧结过程中分解了。加入的金属3Ti+Al较少时，在TiB₂-Fe金属陶瓷中没有发现TiC相，更没有TiB₂+TiC双硬质相，而添加少量的金属间化合物Ti₃Al，依然有TiC相，以及TiB₂+TiC双硬质相。与TiB₂-Fe金属陶瓷比较，添加较少量3Ti+Al或Ti₃Al的TiB₂-Fe金属陶瓷中TiB₂晶粒尺寸略小，这是由于Ti溶入液相Fe中的量大大增加而导致TiB₂晶粒析出时数量多且细所造成的。TiB₂-Fe-Ti₃Al系金属陶瓷在1550℃烧结生成了TiAl₃相。制备了加入较少量的金属3Ti+Al，或金属间化合物Ti₃Al的TiB₂-Fe基金属陶瓷，以及TiB₂-Fe金属陶瓷，比较了他们的力学性能。 添加少量的Ti₃Al或（3Ti+Al）的TiB₂-Fe系金属陶瓷有较好的强度-硬度性能组合，有潜在的应用前景。更多还原

【Abstract】 Intermetallic compouds. such as Ti3Al, Ni3Al, NiAl, FeAl, especially Ti3Al, which are of same crystalline structure and proximate lattice parameters, are expected to improve properties at elevated temperature of TiB2 ceramic.By means of SEM, EDXA and XRD, the sturcture, components and phases of the TiB2-Fe, TiB2-Fe-(3Ti+Al), and TiB2-Fe-Ti3Al cermet sintered in protective atomosphere were studied. The effects of adding 3Ti+AI or Ti3Al on the structure and properties of TiB2-Fe cermet were also dealed with. If the amount of additives being enough, whether no matter w hether in the form of 3Ti+AI or Ti3Al added, two hard phases structure of TiB2+TiC are formed in these cermets. The size of TiB2 crystallines in TiB2-Fe-(3Ti+Al) and TiB2-Fe-Ti3Al cermets are little larger than that in TiB2-Fe cermet No Ti3Al compoud is formed in TiB2-Fe- (3Ti+Al) cermet TiB2 and Ti3Al are not combined together in TiB2-Fe-Ti3Al cermet, and some Ti3Al is decompoed during sintering process. The binders in the above cermets are alloys composed of several elements. During the process, the TijAl compound in TiB2-Fe-Ti3Al mixture are decomposed and formed TiAl3 compound. If the amount of additives is not enough, no TiC, even less two hard phases structure of TiB2+TiC is found in TiB2-Fe-(3Ti+Al) cermet, but TiC and two hard phases structure of TiB2+TiC are still formed in TiB2-Fe-Ti3Al cermetthe size of TiB2 crystallines in TiB2-Fe-(3Ti+Al) and TiB2-Fe-Ti3Al cermet are little smaller than that in TiB2-Fe since that a large amount of Ti disolving into Fe liquid cause precipitating a largeamount of fine TiB2 crystallines. Some TiB2-Fe, TiB2-Fe-(3Ti+Al) and TiB2-Fe-Ti3Al cermets were manufactured, and the physical and mechanical properties were compared.TiB2-Fe cermet added alittle amount of Ti3Al or Ti and Al with nice combination of strenth and hardness, is of potential applications in future.更多还原