What is silicon carbide(SiC) and its common use?

Silicon carbide, often known as SiC and carborundum, can be rarely found in the natural mineral deposit and meteorite. SiC is a ceramic compound which is binding with silicon and carbide, and has diverse types since its different atoms stacking arrangements. So far, we can see many colors of them, such as green, black, or brown, using in various industries. As massive demands and rare spread in nature, most of the SiC are made artificially. Requiring extreme high temperature for over 2000 degrees and only little production per time, it still exists challenges in manufacturing SiC materials.

SiC is first discovered in 1893 and has been started to applied in abrasive machining due to its great resistance of wear and high hardness and rigidity. In addition to these mechanic properties outlined above, it bears high thermal conductivity and low thermal expansion coefficient, resulting in outstanding thermal shock resistance. Since SiC can withstand high temperature condition without distortion and broken, it is majorly applied in automobile industries for brake and clutch. It is also utilized for bullet-proof vest in military and defense industries and fuel components in gas-cooled reactor in nuclear power industry. And for MOSFET in semiconductor industry, people has substituted silicon to silicon carbide for higher power switching. Even the substrate made by SiC can be ten times effective in thermal conductivity than conventional sapphire substrate. It is considered that SiC has led a new materials revolution.

Difficulties in SiC machining

As most kinds advanced ceramics, SiC also possesses extreme hardness and brittleness that cannot endure excessive power of knocking. Improper cutting force can generate sub-surface damage and micro-crack in the structure, causing scatter and uneven machined surface. The cutting scraps removal is also an essential part for SiC precision machining, the hard scraps might damage the materials or accumulate inside the micro holes.

What does Ultrasonic Machining bring to Silicon carbide processing?

Not only for SiC, ultrasonic machining technology has regarded as effective and economic method to process hard and brittle materials, such as ceramics and carbide. With the assistance of high frequency vibrations in controlled amplitude and resonance, we can dispearse uncontrolled, excessive cutting resistance and prevent micro-crack inside, creating greater quality. The relative smaller crash in each cycle cause little damage on tools than conventional CNC method, which effectively in prolonging tool life.

Compared with other SiC processing solutions, ultrasonic machining doesn’t have the restriction of thickness and risk for edge coking than laser machining does；as for water-jet machining, ultrasonic machining can reach the same precise cut and without the limitation for one-time processing.

Let’s take a look at two SiC machining cases that used ultrasonic machining for more information about ultrasonic machining achievements.