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Compared to silicon carbide, silicon nitride, aluminum oxide, and zirconium oxide, what are the advantages and disadvantages of silicon carbide?

Release time:

2020-09-30

Their performance is compared extensively in the literature; the biggest drawback of silicon carbide is that it’s extremely difficult to sinter!
Silicon nitride is relatively expensive!
Zirconia’s phase-transformation toughening effect is unstable and exhibits time-dependent behavior. Once this issue is overcome, not only zirconia—but the entire ceramics field—could see a breakthrough!
Alumina is more common and cheaper, and it boasts good temperature resistance and strength. Zirconia has better wear resistance than alumina and can withstand higher temperatures, but its thermal shock resistance is inferior to that of alumina. As for silicon nitride, it offers excellent overall performance in terms of wear resistance, thermal shock resistance, and strength—but its operating temperature is lower than that of the other two materials. It’s also the most expensive.
Alumina ceramics are the earliest ceramic materials to be developed and remain in use today. They are inexpensive, have stable performance, and offer a wide variety of products. The market for alumina is undoubtedly the largest—why is that? Once you compare it with the other two, you’ll understand.
The comparison is mainly based on performance and price. From a market perspective, that translates to cost-effectiveness.
In terms of price, alumina is the cheapest, and the preparation process for powder raw materials is also highly mature. The other two materials, however, have obvious disadvantages in this regard, which represents one of the key bottlenecks hindering their development.
In terms of performance, silicon nitride and zirconia significantly outperform alumina in mechanical properties such as strength and toughness, and their cost-effectiveness also seems reasonable. However, in reality, many issues exist.
Let’s start with zirconia. It boasts high toughness thanks to the presence of stabilizers. However, this high toughness is time-dependent: for instance, when zirconia components are left in air for a period of time, they become unstable, leading to a severe degradation in performance—potentially even cracking! Moreover, at high temperatures, the metastable phase disappears, thereby eliminating the characteristic of high toughness. As a result, both its high-temperature performance and its time-dependent stability at room temperature severely limit the development of zirconia. In fact, among the three materials we’re discussing, zirconia has the smallest market share.
Speaking of silicon nitride, it has also been a popular ceramic material over the past two decades. However, its finished-product manufacturing process is more complex than that of alumina. While its applications are significantly better than those of zirconia, they still fall short of alumina's performance.