HVOF vs Spray and Fuse

[Danmarco]

Hello

Which one has better bonding strength?
Are there any studies??

Thanks

[Gordon]

Hi Danmarco

Spray and fuse will have a very much higher bond strength.

[Stephen Booth]

What is the calculated bond strength of NiCrBSi coating fused on a ferrous substrate.

Could a 3 lug guided sheer test provide some data.

I have always worked on the basis of 60,000 PSI

[Vadim Verlotski]

Hello Stephen,
From what I've learned from working with NiCrBSi, the bond strength, which also equals the tensile strength of this material, is less than 45,000 PSI (< 310 MPa). This is due to the fact that fused NiCrBSi has large, closed pores, which severely limit its strength.
By the way, you can measure the adhesive strength and tensile strength of the fuse NiCrBSi layer directly in a tensile test by coating two steel stamps with the NiCrBSi and then sintering them together in a vacuum furnace.

[Stephen Booth]

thank you Vadim Verlotski