Thermisch gespritzte Al-Al_2O_3-Schichten von Fuelldraehten mit 'self propagating high temperature synthesis' (SHS)

摘要

Within this project two types of cored wires, Al+Al_2O_3 and Al+Cr_2O_3, were manufactured. Both wire types consist of an Al-sheath (tube) and mechanically alloyed Al+Oxide powder core. The mechanically alloyed powder Al+Cr_2O_3 forms a self propagating high temperature synthesis (SHS) during the spraying process. The very high reaction enthalpy of the exothermal process increases the temperature of sprayed particles what, in consequence, can positively influence coating properties such as bonding, cohesion and wear resistance. In consideration of these circumstances special tube cored wires with an Al-sheath and Al+Al_2O_3 and Al+Cr_1O_3 mechanically alloyed powders were manufactured. As spray techniques, a conventional, high velocity flame and plasma wire spray process were used. Coatings constitution was characterised using optical and scanning electron microscopy. The structure of coatings was described using X-ray examinations.