WS2 / MoS2 additive question.

[Wrehch]

Looking for a answer from the additive experts about Tungsten Disulfide WS2 as a replacement for Molybdenum Disulfide MoS2. From the data I see on this suppliers page http://www.lowerfriction.com/compare.asp it looks like the WS2 provides greater protection, has a greater load bearing ability, lower coefficient of friction and greater heat handling ability than MoS2.

My question is why is this not used (or is it?) in place of MoS2 in lubricating oils and greases? Is it that it cost more or are there other reasons. Many specialty lubricant manufacturers make a "Moly" engine oil and grease. Why don't they make a "Tungsten" engine oil and grease? Most peoople that purchase these higher dollar lubricants are buying them for the added protection they get from the Moly additive package. It would seem to reason that if Tungsten provided better protection it would be the way to go. Any input from the experts would be appreciated.

Mike

 

[GMorg]

From the link above: [price of] "Tungsten Disulfide was almost 10 times that of Molybdenum Disulfide"

I think the quote above explains why WS2 has been used instead of MoS2, historically. Today, you are likely to see more being used in grease-type applications, but from a marketing point of view, customers "know" the term "moly". Tungsten will have to prove its way onto the market.

 

[Wrehch]

According to the site the price of the two are rather close now. That's why I was asking why it is not being used more. I was wondering if there was a reason other than cost that it is not being used.

Quote: "Till few years ago, price was Tungsten Disulfide was almost 10 times that of Molybdenum Disulfide. But since then price of Molybdenum Disulfide has doubled every six months. Now the prices of both chemicals are within comparable range. Now, it makes more economic sense to use superior dry lubricant (Tungsten Disulfide) and improve the quality and competitiveness of final product."

 

[bruce381]

""According to the site the price of the two are rather close now.""

looks like at most $28 per lb MOLY is far les in price and better avalibility last I looked which is old Moly was in the $8-11 lb range