Why did you pick Alimina ceramic? The properties look very nice, especially with anti-wear and being used in plumbing applications:I've been using Alumina Ceramic balls in my SSV43 for awhile now, ordered them from AliExpress and they seem to hold more heat than borosilicate balls, they have similar thermal properties to SiC for a significantly cheaper price. I've checked them after a month of everyday use and they're still in perfect condition.
Here's where I bought them, I got 200 and had a few to spare. https://www.aliexpress.com/item/1941197528.html?spm=2114.12010612.8148356.32.2d9b1fd05Pvrib
This seller also sells 3mm SiC balls but you have to buy at least 500 and that comes out to $125 vs $35 for 200 Alumina Ceramic balls.
US $125.0 |3mm Silicon Carbide Ceramic Ball 3mm SiC Ceramic balls G16 500pcs/Lot 3mm SiC balls ceramic balls|Bearings| - AliExpressSmarter Shopping, Better Living! Aliexpress.comwww.aliexpress.com
"Al2O3 ball is anti-wear, heat-resistant, anti-oxidant, and corrosion resistant, in salt solution
and other chemicals. One feature of Al2O3 ball is its size remains unchanged up to 1100degC.
Al2O3 ball is mainly used for pump, valve and flow-meter
1. Al2O3 content is 99.5%
2. Non-standard size could be supplied
3. Fracture toughness is relatively lower
4. Al2O3 ball is not suitable for application in HCI acid, HF acid and strong alkali"
Sounds perfec. A the temperatures we're using, we probably won't be experiencing any dust, we're well below the meltiing point, it's size won't even change, but 2000 knoop (what I can find as a rating for alumina ceramic), that's ~9 or corunom on the mohs hardness scale. That's not what concerns me. What concerns me is
"Alumina is produced by firing a tightly packed powder form of Al2O3 which includes some binder material. Commercially available grades range from 90% up to 99.95% with the higher purity generating somewhat higher hardness."
What is that binder material as well? We're .45 off of max purity, can that binder change? Call me overanxious if you want, but I don't trust a seller with so few sales and I'd like to know what that binder is. The MSDS for alumina looks very nice, no known health hazards, and this is the toxicology report:
"In general, aluminas are efficiently eliminated from the lung and are considered to be nuisance dusts; their role in fibrogenic lung disease remains unclear. High aluminium levels (between 400 and 1080 mg/kg of wet pulmonary tissue) have been found in the lungs of subjects exposed during 10 to 37 years to alumina dust.Animal experiments indicate that prolonged inhalation of alumina involves a rise in the concentration of aluminium in the brain. A review of the literature (1957), on the pulmonary toxicity aluminium carried out in the USA concluded that aluminium, aluminium oxide and aluminium hydroxyde Al(OH)3 do not cause pulmonary effects; the lesions reported by some authors would result from the presence of other substances."
Only negative I can think of is a study re. inhalation of alumina dust, but again, resistance to wear and these aren't really moving since they aren't changing size.