FORMATION OF NOVEL CARBON BY CONTROLLED OXIDATION CARBIDES AND DEVELOPMENT TO FABRICATION OF CARBIDE/CARBIDE COMPOSITES

将ZrC单晶在600 ~ 150℃的氧气和氩气混合气氛中，在0.02 ~ 2 kPa的氧分压（Po_2）下等温氧化1 ~ 20h。ZrO_2量表由1区和2区两个子量表组成。1区的界面由大小为2 ~ 10 nm的立方ZrO_2 （c-ZrO_2）晶体的111200和220晶格和非晶相组成。晶状体生长在第2区，可见第1区和第2区界面。成功地分离出了具有1区性质的黑色薄膜，该薄膜由含有20 nm大小的c-ZrOX_n颗粒的无定形碳组成。用浓HF溶液处理氧化后的ZrC，可分离出氧化板和碳膜。TEM和拉曼光谱分析表明，在700 ~ 1100℃的低温下得到的薄膜是无定形的。薄膜中碳的六边形平面趋于生长；在1500℃时，光晕转变为圆弧或圆环。t-ZrO_2颗粒在碳膜中分散，粒径在几至几十纳米之间。

A ZrC single crystal was oxidized isothermally at temperatures of 600 to 150 0C in a mixed atmosphere of oxygen and argon with an oxygen partial pressure(Po_2) of 0.02 to 2 kPa for 1 to 20h.The ZrO_2 scale was shown to consist of two subscales, zones 1 and 2. Interfacial area in zone 1 was composed of regular lattice fringes corresponding to the 111,200 and 220 lattices of cubic ZrO_2 (c-ZrO_2) crystallites of 2 to 10 nm in size and amorphous phase. The growth of crystallites occurred in zone 2, which visualized the interface of the zones 1 and 2.Black thin films reminicent of zone 1 were successfully separated, which were composed of amorphous carbon in which c-ZrOX_n particles of 20 nm in size were included. Two subscales could be separated as oxide plates and carbon films, respectively, from the oxidized ZrC by treatment with a concentrated HF solution. The films obtained at low temperatures (700 to 1100ﾟC) were amorphous, as evidenced by TEM observation and Raman spectra.The hexagonal planes of carbon in the films tended to grow ; on the electron diffraction pattern, halos changed to arcs or rings at 1500ﾟC.The t-ZrO_2 particles, several to tens of nano-meters in size, were dispersed in the carbon films.