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TiC由于其低密度、高硬度、易加工性,以及与铁族金属的良好接合性而被广泛用于硬质工具材料及其他金属-陶瓷复合材料;另一方面,Ni_3Al金属间化合物在900℃附近具有独特的高温强度和高温抗氧化特性,被认为是金属-陶瓷复合材料中金属相的优选材料.已有的研究表明,TiC汇与Ni_3Al具有良好的界面相容性,TiC和Ni_3Al组成的复合材料具有很高的强度,所以,选择Ni_3Al和TiC作为热应力缓和型梯度材料的金属相和陶瓷相而得到的TiC/Ni_3Al系FGM(functionally graded materials)材料将能够抵抗由于大温度落差而产生的巨大的热应力.但是,由于TiC与Ni_3Al的烧结温度之间差别很大(前者最低为1800℃,后者最高为1300℃),热压温度只能控制在1300℃左右,在该条件下,如不采用“温度梯度烧结”方法来制备整体致密的TiC/Ni_3Al系梯度材料将十分困难,这是因为在富金属侧,由于Ni_3Al的粘结作用,使得TiC/Ni_3Al复合材料能够致密;但是在少金属侧,如0%,5%,10%,20%(体积分数,下同)Ni_3Al层,由于金属含量少,Ni_3Al相不能完全地粘接TiC使之致密,则得不到整体致密的TiC/Ni_3Al系FGM.因此,TiC和少金属TiC在低温下的热压致密化是一项非常有意义
TiC is widely used in hard tool materials and other metal-ceramic composites because of its low density, high hardness, easy workability, and good bondability with iron group metals. On the other hand, It has been considered as the preferred material for metal phase in metal-ceramic composites because of the unique high temperature strength and high temperature oxidation resistance nearby.Recent studies have shown that TiC and Ni_3Al have good interfacial compatibility, and TiC and Ni_3Al Therefore, the TiC / Ni_3Al FGM (functionally graded materials) material, which is made of Ni_3Al and TiC as the thermal and chemical gradient-type graded materials, will be able to resist the large temperature drop However, since the temperature difference between TiC and Ni_3Al is very large (the former is the lowest 1800 ℃, the latter is 1300 ℃), the hot pressing temperature can only be controlled at around 1300 ℃. Under the conditions , It would be very difficult to prepare an overall dense TiC / Ni_3Al graded material without using the “temperature gradient sintering” method, because on the metal-rich side, due to the binding effect of Ni_3Al, TiC / Ni_3Al composites can be dense; however, the Ni_3Al phase can not be completely bonded to Ti_3Al due to the small amount of metal in the less metal side such as 0%, 5%, 10%, 20% (volume fraction) Of the dense, you can not get the overall compact TiC / Ni_3Al-based FGM.Therefore, TiC and less metal TiC hot pressing densification is a very meaningful