Study of Gas Detonation of Acetylene - Oxygen Mixtures Diluted with Argon or Helium and Their Application in Detonation Spraying
D. K. Rybin, V. Yu. Ulyanitsky, I. S. Batraev
Lavrentyev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: gas detonation, detonation spraying, helium, argon, pure titanium coating
Abstract
A study was conducted on the detonation of oxyacetylene mixtures diluted with helium or argon in an extended channel with a flow-through feed of explosive mixture components at atmospheric pressure. The steady-state detonation velocity, temperature, and dynamic pressure of the products were calculated. The limits of self-sustaining detonation in a 26 mm diameter channel were determined. These limits are achieved by diluting an equimolar and stoichiometric mixture to 92% with both helium and argon. Near these limits, near-spin detonation is initiated without a noticeable transition from combustion to detonation by a booster charge of an equimolar oxyacetylene mixture, the volume of which does not exceed 180 cm3 or 13 channel calibers. Detonation coatings made of pure titanium were obtained using both helium and argon as the purging gas. Helium produces a dense coating with a porosity of <0.5% and a microhardness of 370 HV300. Argon can be used to produce coatings with a developed surface and high (tens of percent) porosity in the surface layer, which have potential for use in catalytic reactors and the production of medical implants.
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