The Benefits of Using Carbide Tools in Manufacturing

Description

Hard materials known as cemented carbides are frequently employed in cutting tools and other industrial settings. It is made up of tiny carbide particles that a binder metal has bonded into a composite. Tantalum Carbide (TaC), Titanium Carbide (TiC), or Tungsten Carbide (WC) are frequently used as the aggregate in cemented carbides. In industrial applications, the terms "carbide" or "Tungsten Carbide" typically apply to these cemented composites. In contrast to high-speed steel or other tool steels, carbide cutters often leave a better surface finish on an item and enable faster machining. One of the main factors enabling the faster machining is that carbide tools can endure higher temperatures at the cutter-workpiece contact than conventional high-speed steel tools. Carbide is typically preferable when cutting hard materials like carbon steel or stainless steel, as well as when other cutting tools would wear out more quickly, like in high-volume manufacturing runs. High-speed steel is preferred because it is less expensive in circumstances when carbide tooling is not necessary.

Cemented carbides are metal matrix composites, similar to concrete in which a gravel aggregate is suspended in a cement matrix, in which carbide particles act as the aggregate and a metallic binder acts as the matrix. Although the abrasive particles in cemented carbide are conceptually considerably smaller than those in grinding wheels, the material of a carbide cutter appears homogeneous at macroscale.

Sintering or Hot Isostatic Pressing (HIP) is the process of fusing the carbide particles with the binder. The material is heated during this procedure until the binder transitions into a liquid state, while the carbide grains, which have a significantly higher melting point, stay solid. The carbide granules reorganise and compact together at this high temperature and pressure to form a porous matrix. The brittleness of the carbide ceramic is balanced by the metal binder's ductility, giving the composite its high overall toughness and durability. A carbide maker can customise the performance of the carbide to meet the needs of certain applications by adjusting a number of factors, such as grain size, cobalt content, dotation (for example, alloy carbides), and carbon content [1-5].

Compared to other common tool materials, carbide is more expensive per unit and more brittle, making it more prone to chipping and breaking. To address these issues, the carbide cutting tip is frequently used as a small insert for a larger tool that has a shank made of a different substance, typically carbon tool steel. By doing this, the advantages of employing carbide at the cutting contact are obtained without the expense or brittleness of manufacturing the complete tool out of carbide. In addition to various endmills and lathe tools, the majority of contemporary face mills use carbide inserts. However, solid-carbide endmills have also increased in popularity recently in applications where the positives (such as faster cycle durations) exceed the drawbacks (described above).

Tools made of carbide are occasionally coated to extend their life. TiN (Titanium Nitride), TiC (Titanium Carbide), Ti(C)N (Titanium Carbide-Nitride), TiAlN (Titanium Aluminium Nitride), and AlTiN (aluminium titanium nitride) are five examples of these coatings. (Newer coatings, referred to as DLC (diamond-like carbon), are starting to emerge; they allow for the cutting power of diamond without the unintended chemical reaction between genuine diamond and iron.]) The majority of coatings tend to make tools harder and/or more lubricious. With the aid of a coating, a tool's cutting edge can easily cut through a substance without the substance adhering (galling) to it. Additionally, the coating lengthens the life of the tool and lowers the temperature linked to cutting. Typically, a thermal Chemical Vapour Deposition (CVD) process is used to deposit the coating [6-10].

Carbide tooling provided an improvement in cutting speeds and feeds so remarkable that, like high-speed steel had done two decades earlier, it forced machine tool designers to rethink every aspect of existing designs with an eye towards even more rigidity and even better spindle bearings, despite the marketing pitch being a little hyperbolic (carbides are not entirely equal to diamond). Germany experienced a tungsten scarcity during World War II. It was discovered that tungsten in carbides cuts metal more effectively than tungsten in high-speed steel, so carbides were employed for metal cutting as much as possible to conserve tungsten.

Powder metallurgy is typically used to create pobedit, which is typically manufactured as plates of various sizes and shapes. A fine tungsten carbide (or other refractory carbide) powder and a fine binder powder, such as cobalt or nickel, are mixed together, and the mixture is then pressed into the required forms. Pressed plates are sintered at a temperature near the binder metal's melting point, creating an extremely solid and tightly-packed product. The plates of this extremely strong composite are used to make the cutting and drilling tips of metalworking tools; they are typically soldered on. There is no need for post-treatment heating. In Russia, pobedit inlays at the tips of drill bits are still fairly common.

References

1. Jockusch J, et al. Additive Manufacturing of dental polymers : An overview on processes, materials and applications. 2020.
2. Karacaer O, et al. Dynamic mechanical properties of dental base material reinforced with glass fiber. J App Pol Sci. 2002;1683-1697.  
3. Hata K, et al. Development of Dental Poly (methyl methacrylate)-based resin for stereolithography Additive Manufacturing. Polymers. 2021;1-15.  
4. Arnesano A, et al. Fused deposition modeling shaping of glass in filtrated alumina for dental restoration. Cera Int. 2019.  
5. Javaid M, et al. Current status and applications of Additive Manufacturing in dentistry : A literature-based review. J Oral Biol Craniofacial Res. 2019;9:179-185.
6. Sayed A, et al. Current perspectives of 3D printing in dental applications. Braz Den Sci. 2021;24.
7.  Huang G, et al. Review article main applications and recent research progresses of Additive Manufacturing in dentistry. Bio Rese Int. 2022:2022.
8. Zhang Y, et al. Review of research on the mechanical properties of the human tooth. IJOS. 2014;14:61-69. doi: 10.1038/ijos.2014.21.
9. Lin M, et al. Thermal pain in teeth : electrophysiology governed by thermomechanics. App Mech Rev. 2014:66.
10. Osman RB, et al. A critical review of dental implant materials with an emphasis on titanium versus zirconia. Materials;2015 932-958.