INFLUENCES OF MECHANICAL VIBRATION ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SHS CERAMIC-LINED PIPES

Based on using the gravitational separation SHS process to produce ceramic lined pipes under the condition of mechanical vibration with different amplitudes and frequencies in a form of up down motion with one degree of freedom, the influences of mechanical vibration on SHS thermit combustion, ceramic solidification as well as structure and properties of pipes have been investigated. It was found that mechanical vibration with increasing frequency increased the combustion temperature, combustion rate and reaction transformation rate, promoted Al₂O₃-Fe liquid liquid phase gravitational separation and ceramic densification, and made Al₂O_{3 dendrite crystal be changed in size and growth orientation. The results showed from mechanical tests that the various mechanical properties of pipes and surface quality of lined ceramic layers had been improved to a great extent following the mechanical vibration with increasing frequency.}