DESIGN OF COAXIAL LASER CLADDING HEAD

Abstract

Cladding head is one of the most important components of laser cladding System. Material provided in laser cladding may be in the form of wire mostly feeding in lateral manner or it may be in powder form which could be feed either lateral or coaxial manner. Coaxial becomes important whenever the uniform material feeding is required in all around directions. Coaxial may also be of discrete type whenever the number of grooves has produced around periphery of nozzle. As the powder feeding takes place along the laser energy source it is considered as DED (Directed Energy Deposition) process and material deposition on substrate becomes function of both energy source, flow parameters and Nozzle Head. Thats why different variation in nozzle parameters had done like nozzle size (75mm, 55mm, 35mm ), nozzle angle(29.3780, 22.50,170 ), inlet angle ( 00,, 250, 500 ) and after that flow parameters study also has done by changing parameters like density (cu-8978 kg/m3 , Wc-15800 kg/m3 ), carrying gas flow rate (10.06L/min, 20L/min, 30L/min ) and finally the powder inlet rate (5g/min, 10g/min,20g/min) . For all the above cases Argon and Steel has been taken for carrier gas and nozzle metal respectively. Then analyzing of the concentration, standoff distance and powder distribution has done and found that nozzle angle and inlet angle has inverse effect with both whereas height has no effect on the standoff, but concentration increase due to uniform distribution. Similarly, the effects of flow parameters are also considered as with increase in density strokes no. increase and the effect of carrying gas variation on the powder reduced. After having this all-parameters variation, a nozzle could be design as per need like for short nozzle used for internal cladding maintain then nozzle angle and inlet angle at lower side otherwise it may become hotter and could damage the nozzle head assembly but for longer nozzle which could use high angles for easy feeding, but it may affect powder distribution and concentration as well.