4 Types of Metallized Ceramics

Due to the difference in thermal expansion coefficient between ceramic and metal materials, the two materials cannot achieve high-quality direct connection. Therefore, it is first necessary to sinter or deposit a layer of metal film on the ceramic. This process is called Ceramic metallization, and the quality of metallization directly affects the airtightness and strength of the final seal are the most important part of the ceramic-metal sealing process. At present, this process is widely used in many fields such as vacuum electronic technology, microelectronic packaging technology, energy chemical industry, and aerospace.

1. Metallized Ceramic Insulator

Metallized Ceramic Insulators are commonly made of aluminum oxide, zirconium oxide, aluminum nitride and beryllium oxide. A metallic layer will be deposited on specific surface of ceramic body to achieve ceramic to metal, ceramic to ceramic joining, to meet brazing and hermetically purpose.

Metallized Ceramic Insulator is widely used in vacuum interrupters, vacuum capacitors/Thyristors, gas discharge tube, electron tubes, current feedthroughs, X-ray tubes, power switches and so on.

2. Vacuum Ceramic Component

As shown in the picture, this vacuum ceramic component is an Alumina ceramic vacuum switch housing, which is used in the field of power electronics.

Its main function is that through the excellent insulation of the vacuum in the tube, the medium and high voltage circuits can quickly extinguish the arc and suppress the current after the power is cut off, so as to achieve the function of safely breaking the circuit and controlling the power grid to avoid accidents and accidents.

The vacuum switching tube has the characteristics of energy saving, explosion-proof, small size, low maintenance cost, reliable operation and no pollution, etc. It is mainly used in the transmission and distribution control system of electric power.

Relays are one of the most widely used automotive electronic components next to electronic sensors. They are widely used to control car starting, air conditioning, lights, oil pumps, communications, electric doors and windows, airbags, and automotive electronic instruments and fault diagnosis, etc. system.

Metallized Ceramic Insulators used in the relay and some of its products are shown in right photo. The ceramic shell is insulated and sealed. The spark generated by the high-voltage and high-current circuit is connected to the power supply. When the high-voltage DC relay is switched off with load, an arc is generated. The arc is quickly extinguished by the cooling and surface adsorption of ceramics. Put an end to the short-circuit fire caused by the electric arc in the automobile circuit, and ensure the safety performance and service life of the whole vehicle.

3. Metallized Ceramic Ring

Metallized ceramic ring is commonly made from high purity alumina, mainly including 95%, 99% aluminum oxide. As alumina ceramic offer excellent electrical insulation strength, great mechanism strength and good thermal properties, so metallized ceramic rings are always used as a ceramic insulator, ceramic washer at ceramic to metal jointing application in high-voltage, high-current fields.

The most extensive type of metallization is ceramic body with molybdenum/manganese (Mo/Mn) metallization, then a following Nickle plating will be covered on it. Other different metallic coating is available to supply to meet different requirements, like direct silver (Ag) plating on ceramic body, tungsten (W) metallization with gold(Au) plating and so on.

With our art-of-the-state manufacturing equipment, we are able to produce some different shapes from small-size to large-size, also we have very high precision flatting grinding, cylindrical grinding, glazing capability at house, the reach client`s tight dimensional requirement.

As shown in the figure, the metallized ceramic ring is used as a ceramic sealed connector, which plays an important role in the high-voltage and high-current circuit on the car. When the high-voltage DC relay is switched off with load, an arc is generated, and the ceramic sealed connection will cool and surface in time. Absorb the arc and make it extinguish quickly.

4. Metallized Ceramic Tube

The main difference of metallized Ceramic tube than regular ones are the applied metal layer on the appointed area of ceramic body. With the applied metal layer on the surface, it can realize the bonding aim between the ceramic tube to metal, ceramic tube to ceramic tube. The metal film will be attached on Ceramic parts tightly under high temperature cure. Then the Ceramic Tubes could be brazed with Kovar, stainless steel parts together directly.

In order to increase the wettability at brazing process, in common case, an additional metal plating will be covered on metallization layer further, mainly including Nickle plating, gold plating and so on.

In the recent market, alumina metallized ceramic tube is one of most extensive technical parts. They are features of high bonding strength, excellent electrical insulation and mechanical strength.

Sometimes, high precision dimensions are needed to cater to the fitting purpose. With our in-house machining workshop, we are able to make the dimensional tolerance as expected according to customers` specification.