摘要
以白刚玉、鳞片石墨为主要原料,分别外加质量分数为0、2.5%、5%、7.5%、10%的Ti粉,经等静压成型,在流动氮气中于1350℃4 h烧成,制备了含Ti的Al2O3-C试样,测试了试样的常温耐压强度、常温抗折强度和1 400℃2 h下的抗氧化性,用XRD分析了试样及其脱碳层的相组成,并用SEM观察试样脱碳层的显微形貌。结果表明:1)在流动氮气中烧成,Ti粉易于转化为TiC1-xNx(其中0≤x≤1),增强了物相间的结合力,且TiC1-xNx钉扎在基体中,增大了基体间滑移的摩擦力,提高了Al2O3-C试样的强度,外加Ti粉质量分数为5%时最佳;2)加Ti粉的Al2O3-C试样在空气中氧化时,TiC1-xNx氧化后的体积膨胀弥补了石墨被氧化后留下的空隙,阻止了外部O2的扩散,同时在高温的作用下,脱碳层氧化物间形成的钛酸铝和莫来石能胶结基体形成致密层,有效地减缓了内层非氧化物的氧化,提高了Al2O3-C试样的抗氧化性能。
The Al2O3-C specimens were prepared using white corundum and flake graphite as main starting materials,adding into 0,2.5%,5%,7.5% and 10% Ti powder,respectively,moulding by isostatic pressing,then firing in flowing N2 atmosphere at 1 350 ℃ for 4 h.The CCS,CMOR and oxidation resistance of specimen at 1 400 ℃ for 2 h were studied.The phase compositions of the specimens and the decarbonized layer were analyzed by XRD,and the microstructure of the decarbonized layer were observed by SEM.The results show that：（1）Ti powder easily changes into TiC1-xNx（0≤x≤1）during firing in flowing N2 atmosphere,which increases the adhesion force among phases and the friction force among materials,and strength of the specimen is improved.The proper addition of Ti powders is 5%;（2）After oxidation,TiC1-xNx volume expands and fills the gaps left by oxidation of graphite,which prevents the diffusion of O2.Meanwhile,at high temperature,the oxides in the decarbonized layer react forming aluminum titanate and mullite,which links the basal materials forming a compact layer.The compact layer slows down the oxidation speed of inner non-oxides,and improves the oxidation resistance of the Al2O3-C specimens.
出处
《耐火材料》
CAS
北大核心
2010年第1期34-37,共4页
Refractories
关键词
钛粉
Al2O3-C材料
抗氧化性
Titanium powder
Alumina-carbon materials
Oxidation resistance
