Study of self-propagating high-temperature synthesis of aluminium nitride using a laser monitor

Laser Systems for Distant Monitoring of Nanopowder Combustion

“…9 and 10 we present the frames of the high-speed imaging of the combustion process of the same powders using laser illumination. In comparison with [10,11], the area of observation of laser monitor in the present work is larger. It allows monitoring the agglomerate formation; however, it is not well suited for low-temperature stage control.…”

“…The laser monitor scheme can be designed with the proper magnification, required for the particular task. In [10], the agglomerates with the size of 5-30 µm were observed with Navitar DO-5095 objective lens. The laser monitor in the present work resolved the agglomerates observation with the size more than 25 µm.…”

“…Particularly, aluminum-based materials obtained by high-temperature combustion of nanopowders in air offer a number of interesting and potentially high impact commercial opportunities [1][2][3][4][5][6][7][8][9]. Combustion of aluminum and iron nanopowders and their mixtures proceeds at temperatures above 2000 • C and is accompanied by a bright gloving and the scattering of combustion products in some cases [10,11]. Moreover, the combustion of nanopowders is a fast process with a flow rate of a few millimeters or centimeters per second.…”

“…Opportunities for observing high-temperature high-speed processes, in particular, nanopowder combustion processes, appear with the use of laser radiation and high-speed video recording [10][11][12][13][14][15][16][17]. When an observation object is illuminated by narrow-band laser radiation, a part of the radiation is reflected from the surface.…”

“…These imaging systems allow observation through the flame or plasma and visualization of the processes shielded by intensive background lighting. In particular, they can be used to perform diagnosis of the substance surface burning with high intensity of light emission during the combustion or plasma induced processes [10][11][12][27][28][29][30]. For the first time, an active optical system with brightness amplification was used to study the aluminum nanopowder combustion in [12].…”