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From: "George Lendich" <lendich@optusnet.com.au>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-3117736@logan.com>
Subject: Re: [FlyRotary] Re: New rotary engine-mazda points on design
Date: Sun, 7 Sep 2008 12:03:15 +1000
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> George Lendich wrote:
>> Are they really going to have ceramic coatings on the side housings?
> I have nothing to suggest that they will, other than it being the most 
> realistic choice.  The other option is steel inserts.  Steel inserts are 
> doable, but they carry a lot of machining, joining and dissimilar metal 
> baggage.  The ceramics would be a cast/bake in place operation.

Ernest,
As much as I love ceramics for wear durability, I don't believe I would 
favour them for aviation application, as I've heard too many bad reports of 
ceramic coatings failures - paint me paranoid, Again!

My preferred coating would be Det-gun coating. I believe thick enough steel 
plating would negate some of the weight savings of aluminum.

Interestingly  thin carbon steel housing were developed by Powersport before 
their demise, with weights equal (or similar) to  that of aluminium - 
apparently they worked very well, but the wear surface would have to be well 
supported. Apparently all the aluminium housings they trialled were failures 
or too expensive to produce. I believe Mistral has some similar experience 
with aluminium housings but may have found a modified and denser aluminum 
whereby the substrate will withstand the loads from the side seals. It's the 
substrate failure which is one of the problems I am most concerned about 
with ceramics.
I hope Mazda has found the answer.
George (down under)