Hi Gordon,

I have some doubt pertaining understanding about microhardness, maybe you can help me:

1. What the main 3 variables that determine the microhardness?

2. In a lay man term, the higher the microhardness, does it mean the compactness or density of the coating higher?

3. How does deposition quantity of coating per pass (build up per layer) affect the microhardness of the coating? e.g: I have 1 coating build-up at 0.001" per cycle, compare to 0.002" per cycle, what will be the microhardness difference?

4. How does turn table speed and gun traverse speed could affect the microhardness of a coating?

5. How does oxide concentration affect microhardness? Is there any co-relation? e.g: Is a coating with higher oxide concentration has a higher microhardness?

6. How does a partical travel velocity affect microhardness? The faster the velocity the higher mmicrohardness we will get? Does this mean also coating using HVOF will have a higher microhardness compare to Plasma system?

7. Is Velocity of the partical in the coating stream different from one point to another? E.g: The partical V1 at stand-off 3" compare to V2 at stand-off 6", and compare with V3 at 9". at the same stream of flame.

Thanks in advance on the many question posted.

Regards,
Alex

Crushed Carbide und Brazing (BS:1845 CZ6 , 1453 C2 )
Nearest Equivalent Standards: DIN L-Ms60, AWS RBCuZn-A

Can anyone give me an idea what these standards are, in respect to the compostion.

Hi everybody,

My name's yves and I am a new member. Congratulations for the forum, it is really great! I am an aircraft enthusiast and an intern for an Industrial Worldwide Gas Supplier. I am making a market study on aeronautics. Here are my questions :

- What are the surface engineering techniques used to treat aircraft parts, engine parts, landing gears and other parts of an aircraft ?
- What are the gases used and what is their importance, what are their roles in the process ?
- What is the average volume of gas used to treat, say, an engine compressor through thermal spray for abradable coating? what is the ratio (gas expense)/piece treated in this case ?

Can anybody tell me ? Any info on this will be welcomed. If anyone needs info on the aeronautics market, i can share as well.

Enjoy your day everybody !

Looking for used Speedfam Lapping machines, 32" or 48". Will consider all conditions and age.

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Hi guys,
I'm new to the forum so please be gentle!!
I have an F4MB plasma spray gun that i now wish to attempt spraying 'argon shrouded'... I plan to make my own argon shroud, but wonder if anyone has ever tried this on an F4MB before. Any info would be great as i realise developing could take some time.

Thanks
Phil (newbee)

Metallisation Company claims that 90% thermal spray plasma systems operate at less than 40Kw power rating. We are presently planning to buy a 80KW FST or GTV system for chromium oxide and stabilised zirconia coatings, as metallisation offers 50KW system. IS there a way to compare all three systems for our use.
Regards
Ragesh Bateriwala

Gordon,

Have you heard of the shear capability of a coating? any coating like Metco 443. As far as I know, most of the Lap shear Testing for thermal coating is not commenly applicable nowadays. Can you help to elaborate more on this topic? What's the shear capability means, what's it's impact and concern, and what's the importance o knowing the shear capability of a coating.

Thanks.

Regards,
Alex

We manufacture equipment for the nuclear industry, one item being a Tong Ball which is a lead sphere through which passes a tong grab, the ball is mounted in a lead shield housing allowing the operator to gimble the tong anywhere within the containment. At present the lead ball is manufactured and spray coated with chrome to reduce wear in the gimble housing, this is prone to cracking and the operation has become very expensive. Is there another coating such as a form of ceramic or teflon which can be sprayed on a spherical lead surface with an even coat to reduce the final machining and also give the required durability.

Dear Members

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