Evidence-first editorial standard
This guide separates observed facts, engineering assumptions and data that still require confirmation. It does not promise a universal service life or replace the exact product data and project specification.
Silicon carbide is the harder ceramic, and hardness is where its advantage starts and mostly ends
It resists erosion by hard, fine particles better than alumina, conducts heat far better and tolerates rapid temperature changes. It is also costlier, more difficult to make in large flat formats, and as brittle as other monolithic ceramics, so it is chosen for small parts where erosion is extreme rather than for large wear surfaces.
The grade of silicon carbide matters as much as the choice of material
Reaction-bonded silicon carbide contains free silicon and can be cast into complex shapes; sintered silicon carbide has no free silicon and better chemical resistance, at a higher cost; nitride-bonded grades are common in refractory and some wear applications. Two quotations for silicon carbide may therefore describe quite different materials, and the grade should always be named.
Silicon carbide pays where a small part erodes fast and is costly to stop for
Hydrocyclone spigots and apex inserts, nozzles, orifices, splitter edges and some pump components see concentrated high-velocity erosion; a part that lasts longer reduces both the part cost and the number of stops. The guide to ceramic-lined hydrocyclones shows where these parts sit; shaped parts of this kind are made to drawing, as with IC CUSTOM.
Alumina remains the economic choice for large surfaces and sliding wear
Chutes, hoppers, pipe and cyclone walls lose material slowly over a large area, and high-alumina tiles such as IC TILE cover them in standard formats at a lower cost. Where impact rather than erosion limits life, the tougher choice is zirconia-toughened alumina, not silicon carbide — see ZTA or alumina.
Chemistry and temperature can decide between grades
Free silicon in reaction-bonded grades can be attacked by strongly alkaline or some acidic media, which favours sintered grades in aggressive chemistry. The high thermal conductivity of silicon carbide helps in hot, cycling service, but the adhesive or retention behind it still sets the temperature limit of the lining, as explained in bonded versus weldable fixing.
What to ask before choosing silicon carbide
Name the grade and its manufacturing route, the part geometry and tolerances, the service chemistry, pH and temperature, the current part material and its life, and the cost of each stop to replace it. Without that last figure, the higher price of silicon carbide cannot be weighed against the life it gains.