摘要
采用燃烧合成工艺，在超高压氮气下，制备了具有较高致密度的ＡｌＮ／Ｙ_２Ｏ_３陶瓷．研究表明，Ａｌ－Ｎ_２－Ｙ_２Ｏ_３的自蔓延高温合成（ＳＨＳ）过程为：６６０ ℃ Ａｌ熔化，１０００℃ Ａｌ剧烈挥发并与_Ｎ２迅速反应形成ＡｌＮ，放出大量热；当反应温度升至１７２０℃时，Ｙ_２Ｏ_３与Ａｌ_２Ｏ_３形成共晶液相Ａｌ_５Ｙ_３Ｏ_１２，发生液相烧结．高温液相烧结使产物的致密度显著提高，但由于其阻碍Ｎ_２向反应前沿的渗透，产物中残余Ａｌ含量增加随着Ｙ_２Ｏ_３含量的增加，液相烧结作用增强，产物致密度显著提高，抗弯强度及断裂韧性提高Ａｌ－Ｎ_２－Ｙ_２Ｏ_３体系的ＳＨＳ致密化主要发生在燃烧波蔓延方向，具有明显的方向性。
Compact AIN/Y2O3 ceramic was fabricated by combustion synthesis of Al particles in the ultra-high pressure nitrogen (1000 MPa). The SHS reaction procedure of the Al-N2-Y2O3 system is as follows: Al melts at 660 ℃, volatilizes strongly at 1000℃ and rapidly reacts with N2 to form AlN , meanwhile a great deal of reaction heat is released out; When the temperature is up to 1760℃, eutectic melt Al5Y3Ol2 form from Y2O3 and Al2O3, then liquid sintering occurrs. Liquid sintering at high temperature decreased the porosity of reaction zone and greatly improved relative density of products. However, high relative density made reaction ratio decrease and residual Al content increase in the products, because it was more difficult for N2 to penetrate to the reaction zone. With increasing of Y2O3 content in the original powder system, porosity of the products decreases, content of Al in the products increases, and the bending strength and fracture toughness are improved. In Al-N2-Y2O3 system, SHS-densification mainly occurrs along the combustion front.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第2期207-211,共5页
Acta Metallurgica Sinica
关键词
陶瓷
燃烧合成
氮化铝
氧化钇
AIN ceramic, combustion synthesis, Y2O3, gas HIP
