| Summary: | 碩士 === 國立中正大學 === 化學工程研究所 === 84 === The thesis contains two parts. The first part describes the
reverse burningphenomenon in combustion synthesis of ZrB2. In
general, using SHS to produce fine ceramics has a property: the
reaction(ignition) always starts at the heatedend , i.e. the
ignited hot spot always appears first at that place. But,in
theexperiments of ZrB2 reaction, under some reaction conditions
, the ignited hotspot first appeared at the opposite of the
heated end , or at themiddle of thepellet . This may be due to
the nonuniformly distribution of thepellet density,and resulted
in the heat transfers within the pellet. The second part
studiesies combustion synthesis of pellet-train TiC. Pellet
cascades were ignited by the tungsten coil in the glove box.
After the firstpellet reacted, heat of re-action of the first
pellet was utilized by the secondpellet.Because the effectof
interface, the combustion wave velocity of the first pellet was
faster thanthat of the second pellet , and the reaction time of
the reaction was proport-ional to the total length of the
pellet-train. We also studies the influences of interface by
varying the physical properties of the interface.
|
|---|
