Spin combustion

Finally, the combustion zone does not always proceed at a uniform rate, but oscillates in time, slowing down and dren advancing rapidly. This effect is probably due to die non-uniform packing and distribution of die reactants in the compact. Also visual observation shows that the zone is not uniformly distributed around the periphety of the compact, and the observed movement of a hot spot around the periphery is usually refeiTed to as spin combustion. 

Filonenko30 in 1975 investigated the combustion of metal/gas systems and the occurrence of non-steady state phenomena. He described the conditions leading to the occurrence of two types of non-steady state phenomena, i.e. oscillatory and spin combustion. Filonenko and Versheminkov in 197531 reported the spin burning of titanium in nitrogen, and discussed conditions leading to spin and the basic factors which control the process. 

T. P. Ivleva, A. G. Merzhanov, K. G. Shkadinsky, Mathematical Model of Spin Combustion, Soviet Physics Doklady 23 (1978), 255. 

Figure 4. Evidence of spin combustion during the synthesis of Ni silicides [7].

Figure 1.15 Photographic record of hafnium combustion in nitrogen at = 6.0 MPa (a) stationary combustion, (b) second front, (c) self-oscillating combustion, and (d) record of spin combustion at P = 6.0 MPa and = 0.1 MPa.

Figure 1.20 Spin combustion (a) of zirconium and (b) dependence of Zr combustion velocity on argon content in nitrogen at spin combustion.

The combustion product composition at 2.0 MPa corresponded to nonstoichio-metric hafnium nitride HfNg 55 in the whole volume of the sample, and in the case of spin combustion, the nitride layer was only 1-2 mm thick, the other part of the sample consisted of pure hafnium. 

Figure 6.8 plots three temperature profiles measured from Nb powder compacts with and without NbN dilution at different nitrogen pressures. The rapid rise in temperature signifies the arrival of the spinning combustion wave and... 

Lavrenchuk, G.V., Naiborodenko, Y.S., and Merzhanov, A.G. (1979) Spin combustion of gasless systems. Combust. Expl. Shock Waves, 15, 415-418. 

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