Jiang Guojian

Morphologies and growth mechanisms of aluminum nitride whiskers by SHS method—Part 2

The high resolution electron microscopy was used to investigate the microstructure of AlN whiskers. The growth mechanisms of AlN whiskers were VLS and VS mechanism. The phenomenon of stacking fault was analyzed. Moreover, the growth mechanism of dendritic crystal was proposed.

Synthesis of pure molybdenum disilicide by the chemical oven self-propagating combustion method

Abstract A high pure molybdenum disilicide was prepared by using the “chemical oven” enhanced self-propagating combustion method. The mixtures of Si and Ti were ignited as chemical oven. Ammonium chloride was added to the mixed powders to control the propagation rate of combustion. The compostion of product was detected by X-ray diffraction (XRD) and X-fluorescence analysis. Results show the molybdenum disilicide product is single phase with trace impurities. Scanning electron microscopy (SEM) photos show the product by chemical oven self-propating high temperature synthesis (SHS) method is more homogeneous than the product by normal SHS method.

The effect of gravity on the microstructure of TiC material

By using chemical ovens, a series of porous TiC materials have been synthesized on parabolic flight plane. The morphology of combustion product obtained in the present microgravity is quite different from that under gravity condition. TiC materials combustion synthesized in microgravity are more uniform distribution and finer porosity.