Particle velocity in detonation plating

Conclusions

• 1. The acceleration of the particles in detonation plating is effected by dynamic pressure. The velocity attained by the particles is less than the velocity of the detonation products behind the wave front, and decreases with increase in particle density and size. With increase in barrel length, the velocity of the powder particles grows.

• 2. The particle velocity varies along the length of the two-phase pulse-type stream. To minimize variations in the conditions of formation of detonation-deposited coatings, it is necessary to employ powders showing little scatter of particle sizes and ensure an even distribution of powder on the barrel bore section.

• 3. The residence times, in the hot detonation products, of particles in the front and rear parts of a two-phase pulse-type stream may differ by a factor of between two and three. Consequently, such particles may be heated up to different degrees.

• 4. The residence time of particles in the detonation products and hence the extent to which they are heated up can be regulated, without affecting their velocity, by varying the length of the barrel and the distance from the mouth of the barrel to the original site of the batch of powder and also by using powders of different particle sizes.