May 2022: Technical ceramics are utilized for countless applications where conventional materials like steel or plastics will not perform well, or at all. Many of these applications require incredible hardness, wear resistance, and/or high-temperature strength. These might include aerospace and tough industrial situations. Electrical or thermal insulation and resistance to all kinds of chemical attack may be vital properties of parts for medical, semiconductor and instrumentation applications. In this experiment, we take a look at thermal conductivity.
INSACO has developed specialized equipment and machining techniques to fabricate parts from technical ceramics to exacting tolerances that meet the critical needs of today’s design engineers. Since 1947, we have been deeply involved in not only fabricating and polishing precision parts, but our engineers have been a helpful resource to designers in guiding them to the optimal choice of material. Part of these discussions typically includes manufacturing capabilities that best allow repeatable performance while still controlling costs.
It is interesting to note that not all technical ceramics are super hard. Some are fragile, and some are quite tough against impact. In fact, all material properties vary quite a bit between different material choices. Some ceramics like sapphire are totally transparent and can serve as high strength, wear resistant windows or lenses.
Thermal conductivity varies tremendously between materials as well. For instance, some grades of silicon carbide conduct heat on a par with metals like aluminum.
Since it is often surprising to many designers that one of the hardest technical ceramics can actually conduct heat well, we came up with a novel “Science Experiment” to visually demonstrate this feature.
What we did was fabricate simple rods from a selection of technical ceramics and from some representative metals including steel and aluminum. Then as a group, we subjected them uniformly to high heat on one end and put the other end onto a block of ice to see which will melt the ice the fastest.
The fastest ice melting of the group is the CVD silicon carbide, followed closely by plain aluminum metal. Next is aluminum nitride. Followed by a low carbon steel rod for comparison. Sapphire and Alumina are actually the same material, but Sapphire being the single-crystal version of aluminum oxide does exhibit a slightly higher thermal conductivity than the sintered version. The slowest of the group were Quartz and Zirconia respectively.
You can review multiple properties from our comprehensive list of ceramic materials individually or easily compare key properties in our handy “Designers Guide“.
If you are working on a design project, or just contemplating a design that can benefit from technical ceramics, we encourage you to reach out to an INSACO engineer to discuss. We are happy to review your design intentions from a fabricator’s perspective, and share our experiences working with these fascinating materials.