| 摘要 |
An improved kinetic spray system (10) and a method for using the same in a high speed manufacturing environment are disclosed. The improved kinetic spray nozzle system (10) comprises: a gas/powder exchange chamber (49) connected to a first end of a powder/gas conditioning chamber (80) having a length (L) along a longitudinal axis of equal to or greater than 20 millimeters; a converging diverging supersonic nozzle (54), the supersonic nozzle (54) having a converging section (56) separated from a diverging section by a throat (58), the diverging section comprising a first portion (59A) and a second portion (59B), with the first portion (59A) having a cross-sectional area that increases along a length of the first portion (59A) and with the second portion (59B) having a substantially constant cross-sectional area along a length of the second portion (59B); and the converging section (56) connected to a second end of the powder/gas conditioning chamber (80) opposite the first end. The method includes: use of the disclosed nozzle system (10) with the addition of hard particles that permit maximum enhancement of particle temperature while not permitting clogging of the nozzle (54); use of controlled particle feed rates to match the desired very high traverse speeds; and use of pre-heating of the substrate to clean it an to enhance particle bonding. With the disclosed nozzle system (10) coupled with the disclosed methods one can apply kinetic spray coatings at traverse speeds of over 200 centimeters per second with a deposition efficiency of over 80 percent. |
