| title: | Production of ultrafine and nanostructured WC-Co hardmetals from recycled scrap. |
|---|---|
| reg no: | ETF6758 |
| project type: | Estonian Science Foundation research grant |
| subject: |
2.2. Materials Science |
| status: | accepted |
| institution: | TTU Faculty of Mechanical Engineering |
| head of project: | Jüri Pirso |
| duration: | 01.01.2006 - 31.12.2009 |
| description: | WC-Co hardmetals are most widely used wear resistant materials. The properties of hardmetals depend mainly on chemical composition (carbide/binder ratio) and structure (carbide grain size). In order to improve mechanical properties and wear resistance of hardmetals, especially the toughness-hardness relationship, it is necessary to reduce the carbide grain size to the sub-micron scale or even to the nanosize scale. Usually spray conversion process, plasma chemical and chemical vapor condensation has been used to produce nanocrystalline WC-Co hardmetal powders with grain size of < 100 nm. These methods for producing carbides are either so expensive and ineffective. The present work provides a process for reclaiming a hardmetal carbide from a hardmetal scrap. A method of single-stage reduction and carburizing treatment of oxidized tungsten containing scrap will proposed. Procedures are suggested for preparing nanocrystalline tungsten carbide of stoichiometric composition with adding carbon black, high-energy milling and subsequent combined reduction and carburizing treatment of oxidized tungsten carbide-cobalt scrap. No extra equipment is necessary to effect the process of the present work. The cost of the metal carbide reclaimed according to the process of this work has been less than half of the cost of the virgin material and remarkably lower than nanostructural hardmetals. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Sergei Letunovitš | |||
| 2. | Jüri Pirso | Tallinna Tehnikaülikooli Mehaanikateaduskond | ||
| 3. | Mart Viljus | |||