Which is better? Ceramics or Metals?

Which is better? Ceramics or Metals?

As a new high-tech material, ceramic has been widely applied in various industries like Aerospace, Medical, Power Generation & Distribution, Automotive, Process Control & Monitoring, Industrial Equipment, Electronic & Electrical and so on. Ceramic parts can also take place of metal parts in some fields, for example, we use metal to produce ball valve before, but when ceramic is discovered, we found that ceramic has better performance on wear resistance and corrosion resistance, we started to use ceramic materials.

Which material is better? Metals or Ceramics? We have to compare the properties of both materials, then we can find the answer.

Metals in general have high electrical conductivity, high thermal conductivity, and high density. Typically they are malleable and ductile, deforming under stress without cleaving. Their excellent machinability help people make designed parts easily and quickly.

The weakness of metals is that they are often vulnerable to corrosion damage,they can easily react with corrosive liquids (acid, alkaline), for example, steels easily rust when placed in moist air, this will affect the using of steel parts. Also, metals usually have high density, this will increase load for a part on a machine.

Ceramics are generally compounds between metallic and nonmetallic elements and include such compounds as oxides, nitrides, and carbides. Typically they are insulating (not electrical or thermally conductive) and resistant to high temperatures and harsh environments (corrosion resistant). They usually have lower electrical and thermal conductivity, higher stiffness, good resistance to corrosive environments.

Ceramics have lower fracture strength than metals.Because of their susceptibility to cracking, consideration of the strength of ceramics requires consideration of their cracking behaviour.

Unlike metals, ceramics usually cannot be reshaped easily. To shape a ceramic, a mixture of ceramic powders, water, and binder materials is molded into the desired dimensions to form a temporary shape. Then the temporary shape will be sintered in the furnace, after that, they need further machining to reach the size requirement.

All in all, metals and ceramics have their own feature on properties, so we have to consider all factors when choosing material.