Bonding for Combustion/Flame Wire Spraying

[iwan-sedaryawan]

Dear Gordon and Members,
Did you have any experiences for using Bonding Wire Ni/Al 95/5 like product Kanthal SW 806 ( or TAFA 75B and others bonding wire Ni/Al 95/5 for Arc-Spraying system) with Combustion / Flame wire spraying system ? the diameter is 3.2 mm, since we tried and the bonding strength is not good enough. maybe need special procedures or setting in the equipments and gases ?
Your suggestion or comments is highly appreciated.

[Gordon]

Hi Iwan

Sorry, no experience with Ni5Al alloy wires through combustion wire process that I can recall. Normally, Ni/20Al composite wires (Metco 405 types) are used, which provide excellent bond coats with high bond strength and probably just as or more importantly a good texture for holding top coat.

[Stuart Milton]

Hi Iwan,

I agree with Gordon. Ni5Al is an arcspray wire. The temperature of arc spraying causes the Ni and Al to react in a given way so as to create a good bond strength. The temperature characteristics of combustion flame spraying do not produce the same characteristics. Flame spray bond coats would normally be either Ni20Al as Gordon mentioned or in some cases, Al Bronze is used with combustion flame spraying.

[iwan-sedaryawan]

Okay, many thanks for your explanations..