(Ca,Mg)α′-Sialon-AlN-TiN粉的影响
( 1. 东北大学 材料与冶金学院, 沈阳 110004;
2. 辽宁科技学院 冶金工程系, 本溪 117022)
摘 要: 以含钛高炉渣、硅灰、 高铝矾土熟料和炭黑为原料, 采用碳热还原氮化法合成了(Ca, Mg)α′-Sialon-AlN-TiN粉。 用X射线衍射法测定了产物相组成及相对含量,研究了合成温度和恒温时间对反应过程的影响, 并对合成机理进行了探讨。 结果表明: 合成温度对(Ca, Mg)α′-Sialon-AlN-TiN粉的合成过程影响显著, 随着合成温度升高, 产物中α′-Sialon相含量增大, 1 480 ℃时α′-Sialon含量达最大, 是最佳的合成温度。恒温时间对产物相组成的影响不十分显著, 但较长的恒温时间可使还原氮化反应进行得更充分, 恒温8 h的试样中α′-Sialon含量最高, 是较理想的恒温时间。 合成过程中SiO的挥发导致试样较大的质量损失,且随着合成温度升高和恒温时间延长而增大。
关键字: 含钛高炉渣;碳热还原氮化; (Ca, Mg)α′-Sialon-AlN-TiN;工艺参数; 合成机理
of (Ca, Mg)α′-Sialon-AlN-TiN powders from
titanium-bearing blast furnace slag by carbothermal reduction-nitridation
(1. School of Materials and Metallurgy, Northeastern University,
Shenyang 110004, China;
2. Department of Metallurgy Engineering,
Liaoning Institute of Science and Technology, Benxi 117022, China)
Abstract: With titanium-bearing blast furnace slag, silica fume, bauxite chalmette and carbon black as raw materials, (Ca, Mg)α′-Sialon-AlN-TiN powders were synthesized by carbothermal reduction-nitridation (CRN). Phase composition of reaction products was determined by X-ray diffractometry. The influence of synthesis temperature and holding time on synthesis was studied and synthesis mechanism was discussed in detail. The results show that synthesis temperature affects the formation of (Ca, Mg)α′-Sialon-AlN-TiN significantly. Content of α′-Sialon in the products increases with the increase of synthesis temperature and reaches the maximum at 1 480 ℃, which is assumed to be the best synthesis temperature. Holding time does affect the phase composition significantly, but with holding time expending, carbothermal reduction-nitridation reaction proceeds much sufficiently. Content of α′-Sialon in the samples reaches the maximum at 8 h, which is perfect holding time. Volatilization of SiO results in great mass loss of the samples and increases with synthesis temperature increasing and holding time expending.
Key words: titanium-bearing blast furnace slag; carbothermal reduction-nitridation; (Ca, Mg)α′-Sialon-AlN-TiN; process parameter; synthesis mechanism