High thermal conductivity
Low coefficient of thermal expansion
Good electrical insulation and resistivity
Low dielectric constant
High mechanical strength under compression load
Corrosion resistant (gas)
Good thermal shock resistance
Ceramic materials have been produced for custom practices for centuries but they are a rather modern development in medical processes and applications. Used in surgical implants, prosthetics and various medical tools and devices, medical ceramics change lives. Manufacturers fabricate numerous ceramic medical appliances from the oxides alumina and zirconia. Some medical devices, specifically, ceramics-on-ceramics in artificial joint systems, required various modifications before they became such a widely practiced. Among the latest products of medical ceramics are electronic implantable ceramic sensors, a blend of medical processing and modern technology.
Aluminum Nitride (AlN) is an excellent material to use if high thermal conductivity and electrical insulation properties requirement area; making it an ideal material for use in thermal management and electrical applications. Additionally, Aluminum Nitride is common alternative to Beryllium Oxide (BeO) in the semiconductor industry as it is not a health hazard when machined. Aluminum Nitride has a coefficient of thermal expansion and electrical insulation properties that closely matches that of Silicon wafer material, making it an useful material for electronics applications where high temperatures and heat dissipation is often a problem.
AlN commonly comes in substrates up to 1 mm thick which can easily be laser cut. It can also come in thicker forms, however, it can be difficult/costly to manufacture in small quantities if the part requires custom material or significant machining. Shapal Hi-M Soft is often used as an alternative to pure aluminum nitride because it also offers high thermal conductivity and can be machined into complex geometries.
* Note – Aluminum Nitride is susceptible to surface oxidization. When this happens, a layer of Aluminum Oxide forms. This does help to protect the material, however, it impacts the thermal conductivity (Alumina is ~30 W/m.K). In oxidizing atmospheres, this happens around 700°C. In inert atmospheres this layer protects the AlN up to ~1350°C. Bulk oxidation will occur at temperatures above this.