As non-metal tool materials, ceramics are widely used in metal cutting. As heat resistant alloy materials, such as Inconel alloy parts in aerospace industry and other industry increasingly extensive application, puts forward higher requirements for cutting tool, so the ceramic insert was born, the more difficult to machining materials exhibit excellent cutting performance.

Ceramic inserts are manufactured in very similar ways to carbide inserts. Because ceramics do not bond as easily as other materials, they must be subjected to much higher temperature and pressure during sintering.

Ceramic inserts although its hardness, high wear resistance compared with carbide insert a lot, but big brittleness is the biggest flaw, thus failed to get a good development, only for less than the amount of finish machining process, and to avoid discontinuous cutting process. Therefore, when choosing the insert number, it is better to consult the cutter engineer of the enterprise, and choose the product to recommend the product to be more reliable.

Ceramic inserts than compared carbide insert, can bear the high temperature of 2000 degrees, and hard alloy at 800 degrees is soft; Therefore, ceramic inserts have high temperature chemical stability and can be machined at high speed, but the disadvantage is that alumina ceramic inserts are very low in strength and toughness and are easily broken. Because of ceramic inserts, high temperature resistant, high temperature and high speed cutting is more advantageous, because the ceramic low thermal conductivity, high temperature, just on the tip of the heat generated by the high speed cutting as chip away, so most researchers think: alumina ceramic inserts can, and the best above 10 times that of the cemented carbide cutting tools under linear velocity, can truly reflect the advantages of ceramic insert.

In order to reduce the sensitivity of the ceramic insert to the crushing, in an attempt to improve its toughness and improve the impact resistance, it added zirconia or added a mixture of titanium carbide and titanium nitride. Although added to these additives, ceramic inserts are much less tough than carbide inserts.

Another improve alumina ceramic insert toughness method is to add crystal texture in material or silicon carbide whisker, through these special on average only about 1 nm in diameter, 20 microns long strong whisker, significantly increased the toughness, strength and thermal shock resistance of ceramics. It is restricted by its impact toughness and has been used in the field of fine car processing.

Like alumina ceramic inserts, silicon nitride ceramic inserts have higher thermal hardness than hard alloy inserts. It is also good for high temperature and mechanical shock. Compared with alumina ceramic insert, its disadvantage is that it has insufficient chemical stability in processing steel. However, a silicon nitride ceramic insert can be used to process gray cast iron at 1450 feet per minute or higher.

Ceramic inserts are applicable to processing materials: ceramic inserts can not be used for aluminum processing, but they are especially suitable for gray cast iron, ductile iron, hardened steel and certain unhardened steel and heat-resistant alloys. However, for these materials, the application of ceramic inserts is successful, and the appearance and micro-quality assurance of insert edge is required, and the optimal cutting parameters are required.

Related link:

http://www.wococarbide.com/

Posted by: hannahgwendolyn at 09:16 AM | No Comments | Add Comment
Post contains 543 words, total size 9 kb.