Black Particles on Sintered Tungsten Part

[gunnar6]

A sintered tungsten part (SAE-AMS-T-21014, Class 4) was received with a black deposit on the surface. EDAX indicates that the particles contain tungsten. The deposit is well adhere and not removed when ultrasonicallycleaned in IPA. Does anyone have an opinion as to the cause? Could the "black" material be blue tungsten oxide?

 

[NickE]

Was the acceleration voltage low enough that you were'nt exciting the material underneath the "black" coating?

What other elements were present in the "black" layer?

nick

 

[gunnar6]

I don't know the answer to the accelerator voltage inquiry. Work was performed elsewhere. No ther elements were reported. In fact, in their judgement, no oxygen was found; which seems unlikely.