Nanostructure Composition of Diamond-WC-Co

Abstract

The properties of ultradispersed and nanostructured materials with average grain or particle size below 100 nm be different from those of conventional materials that have on a coarser size scale [1, 2]. In the previous paper [3] we have reported that the conditions of carbidization and the size of tungsten carbide particle depend from tungsten dispersivity. The influence of the tungsten dispersivity and the properties of carbonised component on the conditions of carbonisation and the size of tungsten carbide particle in simple and composite systems was studied in this work. From composite system WC-Co-diamond is more interesting. It is compared the processes of tungsten carbidization in the present of cobalt in different gas mediums by the carbon in solid phase and from gas. As a carbonised component in solid phase we were choused carbon black and explosion carbon.lt has been earlier shown [4,5], the mixture X-ray amorphous carbon and diamond, called explosion carbon, can be formed by high temperature (3500–5000 K) impact compression of carbon. The crystalline size in these mixture is varied from a few tens to a few hundreds nm and carbon, which is the impurity to diamond, is X-ray amorphous phase. As shown in [6], the high temperature impact compression of carbon was used for production of molybdenum carbide simultaneous with a diamond. The present paper focuses on the use high depression and defected state of the explosion carbon for acceleration of tungsten carbidization and decrease of temperature of this process in order to produce the nanophased mixture hard alloys with diamond. The conditions of reduction and carbidization of CoWO4 + WO3 by carbon black and explosion carbon was studied in this work and proved the possibility of diamond keeping in the mixture with hard alloys at reduction and following carbidization by explosion carbon.