DIAMALLOY 4700- HVOF

[alvliew]

Hi Everyone,

I writting to seek help on the Diammalloy 4700 powder. To give you a little background. I'm trying to spray this powder to meet the Rolls-Royce Specification. However, one of the criteria we are unable to do so.

How can i mitigate/reduce the oxide inclusion and porosity in a HVOF process particular using Diamalloy 4700? Ive adjusted the O2 to 5%, 15%, increment (from 336SCFH). The oxide inclusionand porosity still exist. Please help...

The parameters:
spray gun - DJ2600
The parameters use - Diamalloy 4700 Technical Bulletin
H2(SCFH) - 1610
O2 - 336 (trial1-5% 352SCFH)
N2 - 909
N2 (carrier) - 41
SOD( in) - 10
angle - 80 deg
fdrt - 16.8% ( 41.8g/min)