Problem solved glassy :shine"
10-22-2015, 09:28 AM,
#1
glassy :shine"
We ara currently sprayfusing test for Ni base alloy powder of hoganas company.
I can not see glassy shine at fusion point.
What is the metter?

base material : SUH3
spray powder : 1335-00
Ni5Cr3Si1.5B2Fe, 45-125micron
spray gun : sulzer metco 5p-II
Nozzle : P7B-G
gas flow : oxygen 60 SCFH at 25psi
acetylene 33 SCFH at 15psi
coating thickness : 0.3-0.4mm
spray distance : 200-250mm
fusing method : torch
preheating(celsius) : 100-200
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10-22-2015, 12:01 PM,
#2
RE: glassy :shine"
(10-22-2015, 09:28 AM)kim jong hun Wrote: We ara currently sprayfusing test for Ni base alloy powder of hoganas company.
I can not see glassy shine at fusion point.
What is the metter?

base material : SUH3
spray powder : 1335-00
Ni5Cr3Si1.5B2Fe, 45-125micron
spray gun : sulzer metco 5p-II
Nozzle : P7B-G
gas flow : oxygen 60 SCFH at 25psi
acetylene 33 SCFH at 15psi
coating thickness : 0.3-0.4mm
spray distance : 200-250mm
fusing method : torch
preheating(celsius) : 100-200

The problem may be in a too low boron content are in Ni5Cr3Si1.5B2Fe powder (only 1.5%). So a material melts at higher temperatures than ordinary self-fluxing alloys with 3% boron. In addition, the flux-effect is with 1.5% boron significantly less than with 3% of boron. I fear that you can not good re-melt this powder with torch in air. For the powder you need a remelting in furnace under protective gas at about 1100°C.
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11-04-2015, 11:02 AM,
#3
RE: glassy :shine"
You are using acetylene when fusing right ?
Also find the best position of torch to actually see the "shine".
Some external light source might be even better.
If all the above are fulfilled and you still can not see the "shine", you wont because of what Vadim said Smile
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03-07-2016, 09:05 AM,
#4
RE: glassy :shine"
Hi,

i am new to the field,

but i had faced similar problems while coating 40 hrc nicrbsi on plungers for glass industry, leading to the over heating of the plungers.

i think, low hardness powders tend to give a little less shine, than the harder coatings,

if the powder is oxidized before reaching the substrate, it tends to give a little less shine.

try reducing the spray distance to 125mm, this will reduce the time for the power to get oxidized in the spray stream.

all the best.

abhay
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